Reign of Rot

2 | CREDITS Reign of Rot DUNGEONS & DRAGONS, D&D, Wizards of the Coast, Forgotten Realms, Ravenloft, Eberron, the dragon ampersand, Ravnica and all other Wizards of the Coast product names, and their respective logos are trademarks of Wizards of the Coast in the USA and other countries. This work contains material that is copyright Wizards of the Coast and/or other authors. Such material is used with permission under the Community Content Agreement for Dungeon Masters Guild. All other original material in this work is copyright 2023 by Scott Mcclintock and published under the Community Content Agreement for Dungeon Masters Guild. Credits Lead Writing: • Scott Mcclintock • Buck Wev Supplemental Writing • Daniel Kahn • Isaac Minarik Cartography: Buck Wev Illustration: • Map of the Doomed Underdark by Marco Bernardini • Zuggtmoy, Rotroots and Fungal Beholder by Jimmy Nijs • Caverns of Slime by Matias Trabold Rehren Editing: • Billy Middleton • Kathleen Harrington Layout: Daniel Kahn Beta Reader: Rory “Death Master” Crawford Creative Consultant: Marc Altfuldisch Foreword Our first volume of the Doomed Underdark expands the Doomed Forgotten Realms, delving deeper into a war-torn Underdark. As with all of our products it has been a team effort. In addition to our usual suspects we were blessed with the tremendous talents and much-appreciated contributions of Daniel Kahn and Isaac Minarik, who are welcome addition to the team. I am also extremely grateful to the wonderful Buck Wev who masterminded much of this product. He is as steadfast and reliable as fine dwarven steel. Most of all, though, thanks to you for spending your hard-earned coin to support our product. Please consider sending us an email to [email protected] and letting us know what you think. Also please consider letting us know where you would like us to go next. Would you like to see more mid-level adventures within the Doomed Underdark? Epic-level adventures pitting your heroes against the demon lords? Or something else entirely?

TABLE OF CONTENTS | 3 Chapter 6 - Mantol-Derith ������������������������44 Introduction ..............................................................44 Mantol-Derith Exterior ..........................................44 Mantol-Derith Interior ............................................46 Chapter 7 - A Man with No Name �������������54 Introduction ..............................................................54 Day One - Starting the Journey ............................55 Day Two - Ettercap Lair .........................................55 Day Three - Grick Burrow..................................... 59 Day Four - Ooze Cave .............................................60 Destination - Myconid Grove ................................ 61 Conclusion ................................................................ 61 Chapter 8 - Neverlight Grove ��������������������62 Introduction .............................................................. 62 The Journey .............................................................. 62 Neverlight Grove .....................................................63 Conclusion ................................................................ 73 Chapter 9 - Descent into the Fungal Depths ��������������������������������������������������������������������74 Introduction .............................................................. 74 The Journey .............................................................. 74 About Zuggtmycos .................................................. 75 The Fungal Frontier ...............................................77 The Fungal Depths .................................................83 Epilogue ....................................................................87 Extending the Adventure .......................................87 Appendix A - Demon Lords of the Abyss�88 Appendix B - Monsters and NPCs������������89 Appendix C - Magic Items�������������������������96 Introduction������������������������������������������������4 Doomed Forgotten Realms ..................................... 5 A History of Doom .................................................... 5 Chapter 1 - Doomed Underdark ����������������6 The Demon Lords ..................................................... 6 Demogorgon and Orcus .......................................... 6 Fraz-Urb’luu and Graz’zt ......................................... 7 Juiblex and Zuggtmoy .............................................. 9 Lolth ............................................................................. 9 Other Demonlords .................................................... 9 Chapter 2 - Underdark Locales����������������12 Araj ............................................................................. 12 Blingdenstone .......................................................... 12 Chaarn Van Sonn ................................................... 12 Cyrog ......................................................................... 14 Darklake .................................................................. 14 Elemental Chaos ..................................................... 14 Fardrimm ................................................................. 15 Gauntlgrym .............................................................. 15 Gracklstugh .............................................................. 15 Gravenhollow ........................................................... 16 Labyrinth .................................................................. 16 Mantol-Derith ........................................................... 17 Menzoberranzan ..................................................... 17 Neverlight Grove ..................................................... 17 The Sharnlands....................................................... 18 The Silken Paths ..................................................... 18 Skullport ................................................................... 19 Sloobludop ................................................................ 19 Ti’bok’bik’bok .......................................................... 19 Wormwrithings .......................................................20 Zuggtmycos ..............................................................20 Chapter 3 - Navigating the Underdark�����22 Underdark Travel ....................................................22 Fungi of the Underdark .........................................23 Environmental Effects ...........................................26 Narrating the Journey ...........................................29 Travel Encounters ...................................................29 Chapter 4 - Rampage ��������������������������������33 Zymorven Crossing ................................................33 Beginning the Adventure ......................................33 Repelling the Gnoll Incursion ..............................34 Chapter 5 - Of Mushrooms and Malice����38 Introduction ..............................................................38 Zymorven Hall .........................................................38 The Fungal Grottos ................................................39 Conclusion ................................................................ 43 Table of Contents

4 | INTRODUCTION L ord Vecna has been known by many names— The Maimed Lord, The Whispered One, The Maker of All That is Secret. He was a great wizard, perhaps the greatest of all time, tutored by the serpentine embodiment of magic itself. He was a supreme archlich of inestimable power, rumored to have stolen the secret of undeath from the demon lord Orcus. He was an emperor, worshiped as a god. Then, through force of will, he became a god. He was betrayed and slain by his closest lieutenant. He was imprisoned in the distant domains of Ravenloft. None of this stopped him. Nothing can stop Vecna. Vecna is more than power. He is knowledge incarnate. He hoards secrets like Tiamat hoards treasure. Vecna’s core belief is that for every person, for every city, for every world, there exists a secret so powerful that it can bring about their downfall. He gathers such secrets to further his divine ascendency. As part of his quest for greater godhood, Vecna besieged the planar hub of the multiverse. Although his plans were ultimately thwarted, he nonetheless managed to plunder the hub’s many secrets. One of these secrets was the existence of worlds beyond that of his birth. Of all these worlds, Vecna was most fascinated by the magicrich realms of Toril. He was particularly obsessed by the eldritch ingenuity of fallen Netheril. Vecna set his eye to conquest. With the patience and restraint of an expert strategist, Vecna spent generations preparing Toril for his arrival. In the planar hub, Vecna learned of the existence of portals that allowed travel between worlds and communicated this information to his most devoted followers. They, in turn, slowly infiltrated every corner of Faerûn from Candlekeep to Silverymoon. Year after year, Vecna’s cultists gathered and obscured knowledge, subverted governments, and patiently corrupted the good-hearted champions of Faerûn, all in the name of their Maimed Lord. At the same time, the archlich Acererak, one of Vecna’s oldest and most loyal servants, traveled to the jungles of Chult to build a hidden, deathtrap dungeon. In the heart of this dungeon, he secreted a device called the Soulmonger, designed to devour the soul of any Humanoid that dies anywhere on Toril. Few knew that the Soulmonger’s purpose was to feed a gestating atropal, the ghastly, unfinished creation of a long-forgotten evil god. Fewer still knew that this atropal was to serve as a corporeal vessel for the godly essence of Vecna. It was agents of Vecna who corrupted the translation of Sammaster’s holy prophecies. This, in turn, inspired the Cult of the Dragon’s Red Wyrmspeaker, Severin, to summon forth Tiamat from her lair within the Seven Hells. The Thayan illusionist and secret Vecnan disciple, Rath Modar, worked with Severin to bring this mad plan to fruition. And so the Soulmonger fed. To one such as Vecna, even the grandest plan is but the seed of an even grander plan. As part of Tiamat’s summoning, a great treasure trove, one fit for the Queen of Dragons, was gathered in tribute. Vecnan agents, posing as cultists of the dragon, stole relics of incredible power, including some of Netherese origin, in service of their lord. Four such artifacts were later found in the Dessarin Valley by cultists of the Elder Elemental Eye. This cult went on to raze and destroy much of the Valley. And so the Soulmonger fed. Soon thereafter, Vecna tricked Gromph Baenre, the archmage of Menzoberranzan, into summoning the many demon lords of the Abyss into the Underdark. Madness and decimation on a catastrophic scale soon followed. And so the Soulmonger fed. The breaking and reshuffling of Annam’s Ordning. Elturel and Baldur’s Gate’s descent into Avernus. Auril’s self-imposed exile and the subsequent eternal winter. In one way or another Vecna, the cosmic master mind, had his hand in it all. And finally the Soulmonger was full. Vecna was reborn. He gathered to his banner all that was evil. Not just his cultists, but orcs from Dark Arrow Keep, yuan-ti from Najara, giants from all across the Sword Coast, and liches from Warlock’s Crypt all fought at his bidding. The Realms, devastated by repeated calamity, fell quickly. In less than a year’s time, Vecna ensconced himself within Waterdeep, declaring himself the Lord of Toril. Evil has ruled the lands ever since. Introduction

INTRODUCTION | 5 Doomed Forgotten Realms Welcome to a dark chapter in the history of the Forgotten Realms. A chapter in which your players are destined to play a starring role. Through their actions, the Realms will find salvation. Or doom. The Doomed Forgotten Realms imagines a world where all the various catastrophes threatened in a Wizards of the Coast hardcover adventure have come to pass. It is an acknowledgment that for every successfully completed campaign there are likely a dozen more that have fizzled out or failed. This adventure serves as a tribute to these failed campaigns. As described in the Rise of Tiamat, “Nations and kingdoms shatter, civilization collapses into bloody war, and chaos reigns supreme. . . Such dark times need not mean the end of your campaign, however. . . The new goal is to bring peace to the world once more.” In the Doomed Forgotten Realms, the neverending parade of apocalypses that have racked the Sword Coast are not an improbable coincidence. They have, instead, been purposefully masterminded or exploited by the archlich Vecna so that he might conquer the Forgotten Realms. For those not familiar with Vecna, he is an iconic villain that has haunted Dungeons & Dragons since its earliest days. His relevant background has been briefly summarized in the Rise of Vecna section. For those interested in a deeper exploration of Vecna’s history, it can easily be found online. Reign of Rot is the first volume in the Doomed Forgotten Realms exploring the Doomed Underdark. It includes a gazetteer describing the Doomed Underdark. It also contains an exciting adventure that takes three to five characters from 3rd to 7th level. A History of Doom Faerûn has changed dramatically in the years since Vecna’s conquest. Tiamat holds court over the dragons of the Realms from atop her Soaring Citadel. Zariel wages war over the cratered ruin that was once Baldur’s Gate. The drow Jarlaxle, one of the last hopes for a dying realm, rules over the sailing city of Qu’madosfan Delmah. And the Frostmaiden Auril’s arctic grasp expands ever outwards. For a more detailed exploration of this brave new world, see our supplemental product the Doomed Forgotten Realms Sword Coast Gazetteer.

6 | CHAPTER 1 - DOOMED UNDERDARK Baphomet and Yeenoghu Baphomet, the Horned King, and Yeenoghu, the Gnoll Lord, both appeared within a stretch of the Underdark known as the Labyrinth when they were summoned to the Underdark. Given their bestial nature and territorial urges, conflict was inevitable. Earthquakes ravaged the lands around them as they battled, opening new rifts and chasms within the Underdark. The battle was quick and bloody as the two demon lords clashed on the Material Plane for the first time in millennia. In the end it was Yeenoghu who prevailed. A massive pack of gnolls entered the fray, providing the distraction Yeenoghu needed to deliver a deadly blow with his triple-headed flail. The Gnoll Lord then moved in for the kill, tearing out Baphomet’s throat with his teeth. But, in his death throes, Baphomet managed to grievously wound Yeenoghu, rending the Gnoll Lord with his horns and claws. Though gravely wounded, Yeenoghu bestowed a portion of his power to the brave gnolls who helped him that day, turning them into Fangs of Yeenoghu. These gnolls helped the Gnoll Lord drag himself through endless tunnels, looking for a place where he might stop and lick his wounds. He left behind a trail of demonic blood from which grew a wild profusion of alien foliage. In time Yeenoghu and his new pack settled within a vast cavern. Other legions of gnolls flocked to his side, vowing to protect their lord while he recuperated from his great battle. Over time the gnolls built a city, Ti’Bok’Bik’Bok with the cavern. For more details on Ti’Bok’Bik’Bok see chapter 2. Recently Yeenoghu has returned to full strength. Shortly after his recovery the demon lord learned that his ancient nemesis, the archangel Zariel, had also created a foothold within the Underdark. A new bloodlust rose upon the Gnoll Lord. He and his armies raised their banner and marched upon Helldoor’s Gate. The Blood War had a new front. Demogorgon and Orcus Demogorgon, the Prince of Demons, appeared within the drow city of Menzoberranzan when he was summoned into the Underdark. In a confused rage, he significantly damaged the city before wandering into the subterranean depths. His wanderings took him to the kuo-toa settlement Sloobludop where, despite the demon lord’s destructive indifference, he was worshiped as a god. The coming of Vecna irrevocably changed the Sword Coast. Where once there was peace, now there is strife. Where once there was hope, now there is despair. Where once there was order, now there is chaos. As above, so below. It was Gromph Baenre, the drow archmage of Menzoberranzan, who brought Doom to the Underdark. Manipulated by Lolth, the Demon Queen of Spiders, as well as the archlich Vecna, Gromph inadvertently cast a spell that summoned innumerable demons and demon lords into the Underdark. For Lolth, this meant she could now easily conquer wide swaths of the emptied Abyss. For Vecna, it fed the Soulmonger and weakened the Realms. For the Underdark, it meant only Doom. Shortly thereafter, as an inevitable consequence to the Incursion, the archdevil Zariel arranged for Baldur’s Gate to be dragged into the Nine Hells. In its place was left a gaping crater leading straight into the Underdark. Zariel, refusing to allow the demons to rage across the Material Plane unopposed, established Helldoor’s Gate, an infernal beachhead amidst the craterous ruins of Baldur’s Gate. Now, years later, unbeknownst to most surface-dwellers, a new chapter in the Blood War has begun. One that might have multiversal consequences. Demons and devils battle tooth and talon, leaving carnage and ruin in their wake. Thus far their battle has been confined to the Underdark, but it is only a matter of time until it explodes upwards and consumes all of Faerûn. The Demon Lords The Underdark is a changed place. Much of this change is due to the presence and actions of fearsome demon lords such as Demogorgon and Zuggtmoy. This section summarizes what has befallen each of the fiendish lords since their arrival within the Underdark. These Abyssal lords make for excellent adversaries for characters who are running or have completed Fall of Vecna. If these characters are already level 20 then consider using Epic Characters, to allow them continue leveling. For new and improved stat blocks of each demon lord, including the Demon Queen Lolth, see appendix A. Chapter 1 - Doomed Underdark

CHAPTER 1 - DOOMED UNDERDARK | 7 Orcus, the Demon Prince of Undeath, was more purposeful upon his summoning. After arriving in the illithid colony of Cyrog, the demon lord began to hunt out other illithid colonies, killing the mind flayers and then raising them as undead thralls. The greatest treasures were the elder brains. Orcus planned to harness their collective energy to create a psionic death burst that would slay all of the living creatures within a thousand-mile of radius,so that Orcus could then raise them as Undead puppets. Demogorgon’s wanderings and Orcus’s machinations were cut short by Vizeran DeVir, a renegade drow wizard who detested Lolth. Sneaking into Menzoberranzan, the archmage attempted a spell to summon together all of the demon lords. Vizeran’s hope was that the demon lords would kill one another, destroying the despised drow city in the process. However, with no heroes to aid him, Vizeran was missing key spell components and, consequently, his spell summoned only Orcus and Demogorgon. Demogorgon reacted with savage fury, immediately tearing into Orcus. The Demon Prince of Undeath tried his best to defend himself but it was too little too late. Howling in triumph, Demogorgon claimed the Wand of Orcus as a trophy before turning his destructive rage upon Menzoberranzan. It was not long before even the mightiest of buildings were turned to rubble and the streets to graveyards. Demogorgon now claims Araurilcaurak, the cavern containing the ruins of Menzoberranzan, as his lair. The demon lord spends months at a time ranging afar, killing indiscriminately any creatures or settlements unlucky enough to cross his path. The influence of the Wand of Orcus often raises these dead creatures as zombies, leaving behind legions of restless Undead. After these intense periods of wanton destruction Demogorgon inevitably returns to Menzoberranzan where he goes into a great hibernation before waking up and repeating the process all over again. A little-known secret is that Orcus did not, in fact, die. Nor was he returned to the Abyss. That which is dead cannot die. Orcus had the foresight to bind his Abyssal essence to a hidden receptacle within the Underdark, much as a lich binds its soul to a phylactery. And from this receptacle he has been reborn. Fraz-Urb'luu and Graz'zt Not all demons conquer through violence. Some do so through seduction and guile. Fraz-Urb’luu, the Prince of Deception, sensed his summoning seconds before it happened. The demon lord bound himself within a

8 | CHAPTER 1 - DOOMED UNDERDARK magical gemstone, thinking that doing so would anchor his essence and prevent his summoning. Such actions were in vain, and Fraz-Urb’luu, now trapped within a magical gemstone, was summoned to Mantol-Derith, a secret trading outpost hidden within the Underdark. With no heroes to intervene, the demon’s sudden appearance stirred up a civil war within the city. Graz’zt, the dark Prince of Pleasure, was summoned to Gravenhollow, an ancient library full of obscure, yet powerful secrets. Time behaves strangely in Gravenhollow and Graz’zt was able to conduct years of research within the passage of but a few hours. While doing so the demon prince learned much of the Underdark, as well as the details behind Lolth’s machinations. Graz’zt then set out for the trade settlement of Mantol-Derith. The demon lord knew that in Mantol-Derith, he would find greedy hearts that could easily be corrupted as well as the luxury goods to which he was accustomed. Unexpectedly, due to the influence of Fraz-Urb’luu, Graz’zt found Mantol-Derith on the verge of tearing itself apart. Graz’zt quickly intervened and through a mixture of bribes and threats restored peace. The most human-looking of demons, Graz’zt is a master of seduction and temptation, and it was quite easy for the demon lord to claim leadership over the fractured town. Graz’zt also claimed the bound Fraz-Urb’luu. The Prince of Deception pretended that by taking possession of his gemstone that Graz’zt had control over him. However, this was a lie intended to lull Graz’zt into complacency. The two worked together, in a secret, uneasy truce, taking advantage of the chaos and destruction caused by their demonic kin to solidify a political coup over Mantol-Derith and its many surrounding areas. Thanks to Graz’zt’s research the two demon lords knew that Lolth had arranged this summoning so that she might conquer their Abyssal kingdoms. In retaliation they rallied the civilized races of the Underdark, chiefly the duergar and svirfneblin, revealing that it was the drow that were responsible for the demonic destruction wrought upon their homelands. Over the next few years the Underdark united against a common foe of demon and drow, destroying entire drow communities in the process. Lolth, in turn has delayed her conquest, fretting over the ongoing genocide of her children. All demons, even the crafty ones, are chaotic by nature. And so it was only a matter of time until one of the two demon princes turned upon the other. Graz’zt, thinking that he had enslaved Fraz-Urb’luu, was caught unaware when it happened, and Fraz-Urb’luu, the Demon Lord of Illusions, managed to imprison Graz’zt within a magical gemstone. Fraz-Urb’luu now rules over Mantol-Derith and many other smaller settlements scattered throughout the Underdark and surface world. He does so through a cabal of chaotic evil rakshasas known as the Hollow Rajahs. These rakshasas often assume the guise of Graz’zt but speak the will of Fraz-Urb’luu. In truth, Fraz-Urb’luu cares little for politics, although he greatly enjoys deceiving others by pretending he is Graz’zt. Instead the demon lord spends his time obsessively searching for the three pieces of his broken staff. The legendary Staff of Fraz-Urb’luu was shattered centuries ago, while the Prince of Deception was imprisoned upon the distant world of Oerth. Fraz-Urb’luu now uses his new-found freedom to search for these hidden fragments. Fraz-Urb’luu has learned to craft magical gemstones that can imprison the essence of slain demons. The demon lord can use these imprisoned essences to bolster his own power. By gaining the power of his rival demon lords, FrazUrb’luu hopes to become strong enough to find and rebuild his staff before then returning to and conquering the Abyss.

CHAPTER 1 - DOOMED UNDERDARK | 9 Juiblex and Zuggtmoy Zuggtmoy, the Demon Queen of Fungi, found her way to the myconid community of Neverlight Grove, drawn by the strength of its fungal vitality. While there she corrupted many of the myconids, slowly bending them to her will. Zuggtmoy then “wed” Araumycos, an enormous fungus that occupied hundreds of miles of the Underdark. With no heroes to stop her, Zuggtmoy was successful in her unholy mockery of matrimony– in truth, a demonic rite of domination–gaining tremendous power in the process. This fiendish fusion of demon and fungi is now known as Zuggtmycos. Juiblex, the Oozing Hunger, was instinctively drawn toward Zuggtmoy, his eternal nemesis. The great slime lord arrived just as the Demon Queen consummated her marriage and was no match for her newfound power. Juiblex was ruthlessly smashed to pieces. And yet, these thousands of pieces each retained a portion of Juiblex’s power. The slimy tadpoles fled through the nooks and crannies of the Underdark. Most of these remnants perished but some managed to survive. Always hungering. Always consuming. These remnants fed first on bugs, then rodents, and then finally Humanoids, growing without bound. These Spawn of Juiblex are now scattered throughout the vastness of the Underdark, sought after by cultists of Juiblex hoping to rebuild their sundered lord. The largest remnant is a roaming acidic lake of slime, known as the Blood of Juiblex. It lurks directly under Zuggtmycos, eating away at the fungal behometh’s roots in hopes of disrupting the unholy union between Zuggtmoy and Araumycos. Lolth Lolth, the Queen of Spiders, remains within the Demonweb Pits, her layer within the Abyss. There she directs her forces as they invade the territories of her many rivals. After engineering the summoning of her rival demon lords, Lolth had one last trick up her sleeve. The demon queen cocooned the Underdark within the strands of an intricate spell that she refers to as the Demon Web. Normally when a demon dies outside of the Abyss they later reform within the Abyss. However, Lolth’s Demon Web prevents this from happening so that any demon that dies within the Underdark and is caught within the web dies permanently. The spell is primarily intended to catch demon lords, and because of this, lesser demons sometimes slip through it safely. Other Demonlords Given the infinite layers of the Abyss it should not be surprising that there is also an infinite number of demon lords. Just as most of the Abyss is uncharted, so too are most of these demon lords unknown. However, the Demon Lords of the Abyss table includes a list of some lesserknown demon lords that you might include within your campaign (adapted from Fiendish Codex I: Hordes of the Abyss).

10 | CHAPTER 1 - DOOMED UNDERDARK Demon Lords of the Abyss Name Title Concerns Layer Abraxus The Unfathomable Magic words, arcane secrets 17: Death’s Reward Admimarchus Prince of Madness Insanity 507: Occipitus Ahazu The Seizer Night, abduction — Ahrimanes Chief of the Cacodaemons Exiles, wanderers 452: Ahriman-abad Aldinach The Lady of Change Transformation 1: Pazunia Alrunes The Soothing Spirit Protection, sisterhood — Alvarez The Purging Duke Inquisition, torture 57: Torturous Truth Alzrius Lord of Infernal Light Fire, destruction 601: Conflagratum Anarazel The Daring Darkness Adventurers 79: Emessu Tunnels Ansitif The Befouler Corruption of religious sites 73: Wells of Darkness Ardat The Unavowed Failing marriages, harpies — Areex The Forgotten Prince Unknown 73: Wells of Darkness Arzial The Blooded Baron Subterfuge 45,46,47: Azzagrat Aseroth The Winter Warlock Cold, ice 566: Soulfreeze Asima The Unanticipated Ill surprises 4: The Grand Abyss Astaroth Diabolus Prophecy — Azael The Ensnared Rebellion, War 422: Yeenoghu’s Realm Azazel Prince of Scapegoats Blame, absolution 137: Outcasts’ End Baltazo The Seeping Sovereign Diplomacy, strategy 1: Pazunia Barbu The Unwelcome Guest Discord, ruined peace — Bayemon Of the Unhealing Wound The afflicted — Bechard The Rotting Husk Decomposition, obsolescence 422: Yeenoghu’s Realm Cabiri The Watching Master Observation 73: Wells of Darkness Charun The Hammerer Massacres — Dagon Prince of the Depths Creatures of the deep aquatic 89: The Shadowsea Dweirgus The Chrysalis Prince The shaping of demonic races 558: The Fleshforges Eblis Of the Unbended Knee Refusal to surrender 1: Pazunia Eldanoth The Bloodless Scion Crime 359: The Arc of Eternity Eltab Lord of the Hidden Layer Hatred, retribution 248: The Hidden Layer Gresil Custodian of Records Abyssal lore — Haagenti Lord of Alchemy Alchemy 548: Garavond Ilsidahur The Holwing King Bar-lurgas 90: The Guttering Grove J’zzalshrak The Errant General Blood War campaigns — Kardum Lord of the Balors Balors, fire 21: The Sixth Pyre Kerzit Guardian of the Tome The Tome of the Black Heart — Kostchtchie Prince of Wrath Frost giants, wrath, rage 23: The Iron Wastes Lamashtu She Who Erases Monstrous birth, deformity 503: Torremor Laraie The Stalking Terror Pursuit — Lazbral’thull The Butcher Torture, bloodletting 73: Wells of Darkness Lissa’aere The Noxious Poison gas 27: Malignebula Luperico The Baron of Sloth Sloth, darkness 128: Slugbed Lynkhab Lady of Regret Depression, desire 297: The Sighing Cliffs Malgarius The Demon Tree Evil Sylvan creatures — Mastiphal The Hunting Sovereign Pursuit of prey 1: Pazunia Munkir The White Guardian Afterlife, back door to Paradise 77: The Gates of Heaven Nekir The Black Guardian Afterlife, back door to Paradise 77: The Gates of Heaven

CHAPTER 1 - DOOMED UNDERDARK | 11 Name Title Concerns Layer Nocticula The Undeniable Night 72: Darklight Obox-ob Prince of Vermin Vermin 663: Zionyn Pale Night The Mother of Demons Motherhood 600: The Endless Maze Pazuzu Prince of the Lower Aerial Kingdoms Flying creatures 1: Pazunia Rhyxali Queen of the Shadow Demons Shadow demons, secrets 49: Shaddonon Sch’theraqpasstt The Serpent Reborn Yuan-ti 111: The Mind of Evil Sess’Innek The Emperor Lizard Lizardfolk, civilization 7: The Phantom Plane Shaktari Queen of Mariliths Mariliths 531: Vudra Shami-Amourae Queen of the Succubi Succubi 73: Wells of Darkness Siragle The Ineffable Secret Oaths 493: The Steeping Isle Socothbenoth The Persuader Perversion 597: Goranthis Soneillon The Youthful Crone Rejuvenation 71: Spirac Tharzax The Chattering Prince Poisonous vermin 2: Driller’s Hives Thrallhavoc Shadowmaster Undead shadows, suberfurge — Turgalas The Ebon Maw Hunger, consumption 32: Sholo-Tovoth Ugudenk The Squirming King Worms and hungry parasites 177: The Writhing Realm Verin Voice of Graz’zt Diplomacy 45, 46, 47: Azzagrat Volisupula The Flensed Marquesse Finery, ostentatious ceremony 8: The Skin-shedder Vucarik Consort of Chains Chains, torture 651: Nethuria Yibyiru The Rancid Lady of Bitter Bile Poison 222: Shedaklah

12 | CHAPTER 2 - UNDERDARK LOCALES Now, Blingdenstone is a slime-filled cavern of festering ooze. It is ruled by the Pudding King and a collection of bizarre, sentient Oozes that he refers to as his Royal Court. Despite their gelatinous nature, the Royal Court has as much internal drama and intrigue as that of any Humanoid kingdom. Over the years cultists of Juiblex have journeyed here. Those that survive the royal welcoming feast receive blessing from the Pudding King and are allowed to reside within Blingdenstone. These cultists experiment on behalf of the Faceless Lord, creating new types of monstrous Oozes. The cultists also scour the twisting passages of the Underdark looking for Spawn of Juiblex (see the “Juiblex” section from chapter 1), hoping that if they find enough such remnants they might be used to bring back their dark god. There are a number of notable locales near Blingdenstone. One of the most notable locales is a large, hidden cavern to the west known as Entemoch’s Boon. This cave is sacred to Entemoch, the good-aligned prince of elemental earth. Elemental spells cast within the cavern are remarkably potent. Additionally, hidden within a ring of stalagmites is an ancient, nearly forgotten earth node (see chapter 6 area B6 for details on earth nodes). Chaarn Van Sonn Years ago, Vecna’s gathered forces conquered the dwarfholds of the north. The legendary king Bruenor Battlehammer rallied together the remaining dwarves. One third of his armies, he declared, would march west to Ironmaster in search of allies. The non-combatants, largely children and elders, but also scholars and craftsmen, marched with Bruenor and another third of his army in search of sanctuary. The remaining third of his army, bolstered by the infamous Gutbuster Brigade, stayed behind to harry their enemies and protect their fleeing kin. Bruenor’s journey took him first to Blingdenstone and then, after consulting with some deep gnome sages, to the Elemental Plane of Earth. While in the Elemental Plane of Earth, Bruenor and a portion of his army was captured by the Great Khan of the dao. The remaining army pushed on, searching for the earthen palace of Entemoch. Their search was successful, and Entemoch listened sympathetically to their entreaties. In particular, the Prince of Elemental The Underdark is unfathomably vast, moreso even than the surface world. It is filled with ancient, buried secrets, the crumbling ruins of forgotten civilizations, and fungal monstrosities capable of rending the world asunder. Below is a small sampling of locations that barely scratches the surface of what might be found within the darkness beneath: Araj Araj, also known as the Tower of Vengeance, can be found in a secret cavern east of the Wormwrithings. It is an enormous stalagmite, carved with a spiraling series of chambers leading up to its peak. It was once home to the outcast drow Vizeran DeVir. Vizeran was a spiteful archmage who despised his fellow drow, as well as the Demon Queen Lolth. Vizeran arranged for Demogorgon and Orcus to be summoned within Menzoberranzan in hopes that their inevitable battle would lead to the city’s destruction. Vizeran has since abandoned his tower and now works with the cultists of the Elder Elemental Eye to free the imprisoned deity, Tharizdun the Chained. When Vizeran moved out, he left the tower to Kleve, his death slaad guardian. Since then hundreds of slaadi have gathered within Araj and the surrounding caverns. The chaotic Fiends work to spread chaos and madness throughout the Realms. Through these erratic acts of chaos and madness the slaadi hope to summon their slaad masters, the Lords of Chaos, into the Underdark. Blingdenstone The deep gnome city of Blingdenstone had been ransacked by drow invaders years before the Incursion. When the demons did arrive in the Underdark, the gnomes had just begun to resettle within the ruins of their city. Their resettlement was short-lived. A deep gnome cultist of Juiblex, known only as the Pudding King, sneaked into the city and rallied together an army of slimes and Oozes. With no heroes to stop him, this army assailed the svirfneblin settlers, driving them yet again from their city. Only a handful of deep gnomes remain within Blingdenstone, either by choice or because they are trapped. Many of these gnomes are wererats from Clan Goldwhisker. Those gnomes that were not lycanthropes have had to voluntarily submit themselves to the curse so that they might better hide and navigate within the city’s Ooze-haunted ruins. Chapter 2 - Underdark Locales

CHAPTER 2 - UNDERDARK LOCALES | 13

14 | CHAPTER 2 - UNDERDARK LOCALES Earth was dismayed to hear that Ogremoch, his evil twin, had been unleashed upon Faerûn. Entemoch returned the dwarves to the Underdark, revealing to them the location of Chaarn van Sonn, an ancient dwarven city that could only be accessed through earth node magic (see chapter 4). The lost city had a cache of weapons, as well as mines rich in adamantine and mithral. It was also built around an enormous forge known as the First Forge, whose flames were said to rival, if not exceed, those of Gauntlgrym. These magically empowered dwarves, who refer to themselves as Entemoch’s Chosen, are now debating on how best to take back their former homes from the foul squatters who inhabit them. They are led by Dayvin Flintlock, a paladin who was hand-picked by Bruenor to lead in the king’s absence. Dayvin is protected by two massive galeb duhrs and advised by Gilraka, a stone giant seer. Cyrog Cyrog was once a small illithid colony built along the outskirts of an abandoned bloodstone mine. It was here that Orcus appeared when he was first summoned into the Underdark. The colony’s elder brain, also named Cyrog, had died just before the demon lord’s arrival, and Orcus was quick to turn the fallen creature into an Undead thrall. Using the Undead elder brain, Orcus was able to enslave the rest of the mind flayers. Cyrog now serves as Orcus’s seat of power. Orcus has found Lolth’s Demon Web to be a pleasant surprise and, because of it, has been able to create a host of Undead demons and devils that he now uses to reinforce his city. Over the last few years, Orcus has managed to keep his existence secret. With methodical patience the demon lord is conquering other illithid settlements, building an army of Undead mind flayers. For a glimpse at what Cyrog looked like during the early days of the Incursion see Fall of Cyrog by Daniel Kahn. Darklake The Darklake is not a single underground lake but a vast network of subterranean rivers, tunnels, and canals connecting numerous water-filled caverns and chambers. It spans over 100 miles and has varying depths and heights, with some ceilings reaching several miles high. Years ago one of Juiblex’s generals, a gargantuan crimson slime known as the Blood that Hungers, slurped its way to the bottom of the Darklake. It has since gorged itself on the lake’s denizens, wiping out entire species of marine animals. Its corpulent mass has infected the Darklake. The lake’s foul, gelatinous waters have taken on the bright red tinge of the demonic creature and are now filled with all manner of predatorial Oozes and formless slimes. As of now the corruption has been limited to the interior of the Darklake. The non-Newtonian water along its shores and tributaries looks normal and is safe to drink, even if it is slightly sticky and viscous. Elemental Chaos Because of Vecna’s scheming, the Princes of Elemental Evil were summoned successfully to the Sword Coast. They and their followers terraformed the Dessarin Valley, creating a balanced, tranquil paradise amidst an otherwise apocalyptic world. However, beneath this harmonious paradise, hidden within the depths of the Underdark, is a riotous conflagration of elemental energy known as the Elemental Chaos. This juxtaposition reflects the dichotomous nature of the elements. Whereas the Dessarin Valley has been magically transformed to accommodate humans and their ilk, the maelstrom swirling within the Underdark is openly hostile to anything not elemental in nature. There are many subsections within the Elemental Chaos, most of which remain uncharted. Those few that have been explored include the Frozen Caves, the Lava Vents, the Mud Pits, and the Air Flows.

CHAPTER 2 - UNDERDARK LOCALES | 15 Fardrimm The Fardrimm is a network of ancient tunnels created more than a thousand years ago by the Delzoun dwarves. It connects to many settlements such as the drow cities of Ched Nasad and Yathcol, as well as the former dwarven citadels, Adbar and Felbarr. After the defeat of the dwarves, Vecna placed necrotic beacons, designed to attract undead, throughout some of these tunnels. Over the years these beacons have drawn thousands of zombies, most of which were created by Demogorgon and the Wand of the Orcus. Vecna’s purpose in leaving these beacons was two-fold. First, he hoped the undead would deter the dwarves from resettling within their homelands. Second, it provided the archlich with a ready-made army should he need it. Recently a courageous band of paladins known as the Hell Riders found themselves within the Fardrimm after escaping from Avernus, the first layer of Hell. These Hell Riders have occupied an abandoned dwarven outpost that they refer to as New Elturel. The paladins have committed themselves to the cause of ridding the Underdark of the demons and devils that now infest it. Gauntlgrym Gauntgrym, a subterranean city, was the capital of the ancient dwarven Delzoun Empire. It had cavernous halls, some of which were large enough to hold entire surface villages, with soaring ceilings and towering statues of dwarven gods and heroes. With the coming of Vecna, the dwarves were forced to flee yet again from their ancestral stronghold. A clan of fire giants led by the brutal Duke Zalto moved into the abandoned city. The fire giants were particularly attracted to the Great Forge. Constructed from adamantine and powered by an imprisoned fire primordial, the forge is capable of constructing relics of great power and beauty. The fire giants use the forge to augment and enhance the crafting of their brutally efficient weapons. Some of these weapons are exported to agents of Vecna; however, most of them are used in the fire giants’ tireless war against the dragons of the Realms. Gauntlgrym most easily connects to the surface world, though it also has a few protected tunnels that wind their way into the Underdark. The fire giants primarily trade with the orcs of the ManyArrows tribe that have occupied the surrounding dwarfholds. However, they have more recently established contact with the duergar of Gracklstugh, and have built a strong alliance with the gray dwarves. Gracklstugh Gracklstugh is the duergar capital. The industrious city never sleeps, its ever-burning forges filling the acrid air with cinder and smoke. Although Gracklstugh is nominally ruled by its Deepking, there are a number of other political factions that vie with one another for influence. The duergar capital is built into a large cavern along the southwest shore of the Darklake and has many different tunnels connecting it with other regions of the Underdark. Because of its central location, it is a well-known commercial hub. The demons’ incursion exacerbated pre-existing political tensions within the duergar capital. Most notably, the derro, a race of outcasts living within the slums of Gracklstugh, turned to worshiping Demogorgon. With no heroes to stop them, derro savants infected Clan Cairngorm, a group of stone giants loyal to the duergar Deepking, with a terrible curse that drove them mad. This, in turn, instigated a brief civil war within the city that led to the eradication of first the stone giants and then the derro. Surviving derro were driven from the city, and most now dwell within the ruins of Menzoberranzan. The demon lord Graz’zt took advantage of this turmoil. He arranged for the Deepking’s royal consort to be replaced by a disguised succubus. This succubus, after gaining the trust of the Deepking, arranged for an alliance between the duergar monarch and Graz’zt. At Graz’zt’s

16 | CHAPTER 2 - UNDERDARK LOCALES urging the duergar have declared war on the drow. In return Graz’zt has erected wards around Gracklstugh that prevent Fiends from entering the city (unless they bear a holy symbol of Graz’zt). More recently the demon lord Fraz-Urb’luu imprisoned Graz’z’t and is now masquerading as the Dark Prince. As of now both the Deepking and succubus are unaware of this and believe that Fraz-Urb’luu is Graz’zt. More recently, a mysterious duergar named Adrick Underearth arrived at Gracklstugh. Adrick was a Wearer of Purple, a high-ranking member of the Cult of the Dragon and bore with him the blessing of Tiamat, which he bestowed upon Themberchaud the Wyrmsmith, an adult red dragon that lived within Gracklstugh. Under the blessing of Tiamat, Themberchaud grew in size, becoming as powerful as an ancient red dragon. Following this blessing many of Gracklstugh’s duergar have joined the Cult of the Dragon, which has, in turn, replaced the Keepers of the Flame that previously tended to Themberchaud’s needs. The Cult of the Dragon, bolstered by the newly empowered Wyrmsmith, are popular amongst the common folk, and their political influence now rivals that of the Deepking. Gravenhollow The library of Gravenhollow has always been a bastion of peace. Carved out long ago from the bones of the world and protected by ancient and potent magic, the library possesses a kind of awareness. It blocks and misdirects those unworthy of reaching its gates, even as it facilitates finding the way for those who need it. Such misdirections were no match for the archlich Vecna. The Whispered One seduced one of the caretakers of the library, a stone giant librarian known as Ustova. Ustova is a seer with the ability to see into the future. The stone giant now secretly serves Vecna, warning the archlich about future events that might obstruct his schemes. The two other stone giant librarians, Ulthar and Urmas, currently remain unaware of their sister’s corruption. Labyrinth The Labyrinth is a bewildering network of tunnels and caves that spans hundreds of miles. Traveling through the Labyrinth is a nightmarish task, as the tunnels endlessly twist and turn, often ending abruptly or leading to unexpected destinations. The region is most commonly entered through the Spiral of the Horned King, a maze of tunnels and caves along the northern edge of the Labyrinth. Those exiting the Labyrinth usually exit to the south, passing a banshee-filled rift known as the Pit of Howling Grief Shortly after the Incursion, Baphomet the Horned King and Yeenoghu the Demon Lord of Gnolls squared off against one another in a savage battle. Although hard fought, Yeenoghu proved the victor, dismembering and slaying Baphomet. Because of Lolth’s Demon Web (see the “Lolth” section of chapter 1), Baphomet’s essence was unable to return to the Abyss and, instead, infused itself within the winding caverns of the Labyrinth. An army of minotaurs and ram-headed demons known as bulezau, attracted by Baphomet’s lingering presence, now dwells here. The army is ruled by a fiendish, dark-furred chieftain known as Mahn-tor, the Minotaur Lord. These caves are now a reflection of the Horned King’s Abyssal home. Their passages and tunnels move on their own accord, confounding any attempts to navigate them. Because of this, it is said that the Labyrinth is now inescapable, more prison than maze. For most this is cause to avoid the Labyrinth in its entirety. However,

CHAPTER 2 - UNDERDARK LOCALES | 17 for those seeking seclusion or escape it is seen as a blessing. Most of these hermits and outcasts reside in an abandoned shantytown along the western edge of the Labyrinth known as the Filthriddens. One of the most notable hermits is the drow outcast, Grin Ousstyl, who hides within an impenetrable fortress known as the Adamantine Tower. Grin assisted the archmage Vizeran DeVir with the destruction of Menzoberranzan. Now, plagued by guilt, he hides within his tower trying to figure out how to atone for his sins. In the center of the Labyrinth lies the Maze Engine, a mechanical, magically-powered device capable of altering reality. This extra-planar artifact, also known as the Orderer, hails from Mechanus and was discovered long ago by the archlich Vecna. An autognome lich known as the Death Tinker, has been studying the Maze Engine for years, slowly disassembling it piece by piece. This deconstructed technology has been instrumental in helping Vecna bioengineer the vatborn lifeforms known as artificially accelerated organisms. Mantol-Derith Mantol-Derith is a subterranean trading outpost where surface dwellers peacefully trade with the various settlements of the Underdark. During the Incursion, Mantol-Derith plunged into violent chaos. Such turmoil proved short-lived, however, as the Dark Prince Graz’zt arrived and set things straight, subtly taking over rule of the settlement in the process. Under the demon lord’s rule the drow elves have been driven from the city, castigated for their role in the Incursion. The city also has become a protective haven for other Underdark refugees. Unbeknownst to many, the demon lord FrazUrb’luu recently tricked and imprisoned Graz’zt. Fraz-Urb’luu now rules Mantol-Derith, using powerful illusions to pretend to be the Dark Prince. He has created special gemstones that can trap the essence of slain demons and is currently enlisting the aid of adventurers to empower these gems with the hopes of using their power to escape the Underdark and return to the Abyss. For more details regarding Mantol-Derith, “Graz’zt”, and “Fraz-Urb’luu” see chapter 6. Menzoberranzan Menzoberranzan, one of the most infamous drow cities, was the source of the Incursion. The demons were accidentally summoned into the Underdark by the drow archmage Gromph Baenre. When the spell went awry, Demogorgon clawed his way into the heart of the city, leaving a trail of smashed buildings and madness in his wake. Weakened, Menzoberranzan was in no shape to defend itself when another drow archmage, Vizeran DeVir, purposefully summoned Demogorgon a second time into the city. In his rage, Demogorgon and his demonic entourage decimated the City of Spiders. Now, years later, the ruins of Menzoberranzan serve as a mournful monument to its bygone glory. Demogorgon has turned the city into his lair, and by doing so has attracted a number of demented followers. A feral gang of demon-worshiping drow and driders, referring to themselves as the Bandersnatches, still hide within the city. So too can be found more than a thousand derro that have been drawn to the City of Spiders by Demogorgon’s demonic presence. Over time the city has been warped by Demogorgon’s demonic energies. Most notably the lake Donigarten has bubbled upwards, flooding the southeastern portion of the ruined city. Its now brackish water serves as home to schools of ixitxachitl and at least one ancient aboleth. Neverlight Grove Before the Incursion, Neverlight Grove was a secluded cavern where a colony of myconids lived in peaceful contemplation. The coming of Zuggtmoy changed this. The Demon Queen of Fungi was immediately attracted to the grove, where she built herself a stronghold within a colossal mushroom known as Yggmorgus. Her presence corrupted the colony of myconids, creating strife and division within their community. Once their corruption was complete, Zuggtmoy led the myconids on an unholy wedding procession to witness her union with the fungal entity, Araumycos. After the wedding the myconids returned to Neverlight Grove. Over the years their corruption has deepened. Under Zuggtmoy’s influence the mushroom creatures have become increasingly gregarious. They have also begun to develop personalities, quirks, emotions, and passions more traditionally associated with the non-plant races of the Underdark. These adaptations have allowed the myconids to lure other Humanoids into their grove. However, all is not as it seems within Neverlight Grove. Its outwardly welcoming nature is a trap, and those Humanoids lured into the grove rarely escape. Instead, they are sacrificed to Zuggtmoy and planted within her ever-growing Garden of Horrors.

18 | CHAPTER 2 - UNDERDARK LOCALES The Sharnlands The Sharnlands is a large complex of interconnected caverns located within the lowermost reaches of the Underdark. These caverns are notable for their profusion of sparkling gemstone formations, among which can be found a number of forgotten, partially buried earth nodes (see area B6 in chapter 6). The Sharnlands are named because they serve as the home of the sharn, powerful enigmatic creatures whose origins date back to ancient Miyeritar. These chaotic beings see themselves as protectors of the Weave and have dedicated themselves to fighting back against arcane catastrophes. The demonic faerzress that suffuses much of the Underdark has alarmed the sharn; however, because of their factious nature they have yet to unify on a plan to combat it. More recently the Sharnlands have been overrun by Zariel’s devils, who have been trying to push their way into the northernmost portions of the Underdark. These devils have set up encampments throughout the Sharnlands and have been working to corrupt the sharn, in hopes of bending the strange creatures to their infernal whim. The Silken Paths The Silken Paths are a snarl of near impenetrable spider webs that congest a 500-foot-deep, 2,000-foot-wide chasm that stretches for almost five miles. The webs can be traversed, though it is difficult to do so as the pathways continuously change as older strands deteriorate and newer strands are spun in their place. At the bottom of the chasm can be found one of the few Underdark portals to the Abyss. More specifically, the portal leads to the Demonweb Pits, Lolth’s Abyssal lair. She needs this portal open to continuously cast forth the mystical demon web that keeps all of the other demon lords trapped within the Underdark. Foul abominations ranging from yochlols to strange spider-headed Humanoids guard the chasm. Within its webbed interior can be found all manner of trapped creatures, including a raging balor. Along the bottom of the trench, near the portal, drow refugees band together into an everincreasing army.

CHAPTER 2 - UNDERDARK LOCALES | 19 Skullport Skullport is an underworld city beneath Mount Waterdeep, where anything can be bought, sold, or traded for a price. It is a haven to slavers, smugglers, and mercenaries overseen by thirteen floating, disembodied skulls loyal to Vecna. Unlike Mantol-Derith, Skullport is much closer to the surface than it is to the Underdark, and because of this is a greater commercial hub. Skullhaven is politically influenced by a number of eclectic factions such as yuan-ti slavers, an aboleth Skumlord, and Misker, the beholder pirate. For more on Skullport, including maps, see Fall of Vecna. Sloobludop A small kuo-toa village known as Sloobludop once lay upon the eastern edge of the Darklake. The kuo-toa initially worshiped Blibdoolpoolp, the Sea Mother. However, after the demons’ incursion some of these amphibious creatures began to experience visions of a strange being they referred to as Leemooggoogoon, the Deep Father. Soon the village was rent by a religious schism between Ploopploopeen (“Ploop”), the archpriest of Blibdoolpoolp, and his daughter, Bloppblippodd (“Blopp”), the newly risen archpriest of Leemooggoogoon. Those kuo-toa loyal to Blopp raided the Underdark aggressively, capturing anyone that they could for sacrifice to the Deep Father. The waters of Sloobludop ran red with sacrificial chum. With no heroes to aid them, the kuotoa loyal to the Sea Mother were powerless to intervene, and so the sacrifices continued, growing in both size and frequency until they attracted the attention of the demon lord Demogorgon. The great beast arose from the depths of Darklake, terrible and majestic in his fury. The Prince of Demons rained death and destruction upon the kuo-toa of Sloobludop, destroying their village and killing most of the five hundred creatures that lived there. Saner minds might have seen this as a cautionary tale. Not so the alien intellect of the kuo-toa. Instead, the aquatic beings saw it as divine validation. From the mouths of the survivors, word spread rapidly through the Underdark, and over the next few years, thousands of kuo-toa undertook a holy pilgrimage to the birthplace of “Leemooggoogoon.” These kuo-toa, aggressively zealous in their religious fervor, have raised up a new holy city, still named Sloobludop, in honor of their Deep Father. This sprawling settlement is composed of giant, rickety towers and plank bridges built from whatever scrap material the kuo-toa could scavenge. Much of Sloobludop has been built beneath the black waters of the Darklake, and because of this the growing influx of kuo-toa has gone unnoticed by the rest of the Underdark. The kuo-toa are secretly working on constructing a monstrous multi-headed effigy, hundreds of feet in height, that they hope to transform through the power of their deranged faith into a living version of Leemooggoogoon. To this end the kuo-toa have begun planning a massive invasion upon nearby Gracklstugh in hopes of obtaining supplies that they believe necessary for the completion of their idol. A smaller band of kuo-toa hides along the fringes of the Darklake. Led by Ploop, the original archpriest of Blibdoolpoolp, they remain loyal to the Sea Mother. These disgraced amphibians secretly spy upon their peers and are making plans to hijack the impending kuo-toan transformation ritual and turn the gigantic idol into an avatar of Blibdoolpoolp. Ti'bok'bik'bok Yeenoghu was grievously wounded after vanquishing his rival, the demon lord Baphomet. Scraping and crawling his way into a vast cavern, the Gnoll Lord then spent the better part of a year healing his wounds and regaining his strength. During this time his followers, packs of gnolls and demons, built a makeshift city, Ti’Bok’Bik’Bok, around him. The blood of the demon lord watered the stone of the Underdark, and from it grew strange, alien life. In some places resembling a quiet savannah, in others a steaming jungle, the foliage attracted fiendish versions of surface world fauna. Infernal aurochs, fire-breathing gazelles, and swarms of cackling demon monkeys sustained Yeenoghu’s hosts as they awaited their lord’s revival. Now that Yeenoghu has recovered he has turned his savage ire toward Zariel, his hated nemesis, and her devilish legions. Ti’Bok’Bik’Bok has become more of a military encampment, from which demonic legions sally forth in the desperate hope of winning the Blood War.

20 | CHAPTER 2 - UNDERDARK LOCALES Wormwrithings The Wormwrithings are a honeycomb of tunnels spanning hundreds of miles in the northern reaches of the Underdark. The area is named for its large deposits of wormrock, a porous orange stone that can be easily burrowed through. The stone is also rich in nutrients and mildly addictive. Because of this, burrowing creatures, especially purple worms, can be found here in abundance. The purple worms that live here share communal nurseries. Daring hunters occasionally attempt to plunder these nurseries, as Vecna’s minions are known to pay handsomely for unhatched eggs. Ugudenk, the Squirming King, a lesserknown demon lord, has settled within the Wormwrithings. Over the years Ugudenk has corrupted the surrounding stone, infusing it with demonic energy that induces hallucinations and warps the flesh of any creatures that consume it. Consequently, the Wormwrithings are now full of mutated purple worms, bulettes, and other aberrant monstrosities. There are a number of unusual locales within the Wormwrithings. One such location is the Vast Oblivium, the abandoned lair of the hateful beholder Karazikar the Eye Tyrant. Karazikar was recently captured by minions of Zuggtmoy, and is now imprisoned within the fungal depths of Zuggtmycos. Also within the Wormwrithings can be found the Gargoyle Tube, a demon-infested lava tube located directly beneath the infamous Dungeon of Death. Zuggtmycos The fungal entity known as Araumycos once stretched for hundreds of miles throughout the Underdark. It was likely the largest sentient creature on all of Faerûn, and possibly the most powerful as well. Its verdant body stretched across countless caverns, hiding entire lost civilizations within its moldy bosom. The Demon Queen of Fungi, Zuggtmoy, has since possessed Araumycos, creating an unholy union referred to by many as Zuggtmycos. Under the demon lord’s influence, Zuggtmycos has expanded greatly. Its mushroom bones have broken through to the surface world, creating a vast fungal forest. Its sinewy roots have dug their way deep into the crust of the world, triggering earthquakes of apocalyptic magnitude. Zuggtmoy’s power now dwarfs that of any of the other demon lords. She hopes to use this power to turn all of Faerûn into a nightmarish reflection of her own rotting kingdom, ultimately replacing all flesh-and-blood life with myconid servants.

CHAPTER 2 - UNDERDARK LOCALES | 21

22 | CHAPTER 3 - NAVIGATING THE UNDERDARK The Underdark is a vast network of caverns, tunnels, vaults, and passages stretching from one end of Faerun to the other. Its physical features are even more varied than those of the surface world. Subterranean rivers, fungus fields, deep gorges, underground cities, yawning chasms – the adventurers will have to deal with all of these features and more. Underdark Travel Much of the party’s travel through the Underdark is handled abstractly, using the rules and advice in chapter 8, “Adventuring,” of the Player’s Handbook. The following specific guidelines apply to travel in the Underdark. Travel Pace Travel pace in the Underdark is significantly slower than for overland travel. Not only are the tunnels and passages often difficult terrain with uneven surfaces, but routes in the Underdark are rarely direct, and the characters must follow available passages and their various twists and turns, climbs and descents. Creatures that can burrow through solid rock (such as purple worms) move at their normal burrowing speed, but this isn’t likely an option for the party. Underdark Travel Pace Pace Miles Per Day Effect Fast 8 −5 penalty to passive Wisdom (Perception) scores Normal 6 — Slow 4 Able to use Stealth Underdark Travel Times Location Mantol-Derith Blingdenstone Menzoberranzan Neverlight Grove Gracklstugh Sloobludop Mantol-Derith — 8 days 8 days 16 days 19 days 19 days Blingdenstone 8 days — 8 days 16 days 20 days 20 days Menzoberranzan 8 days 8 days — 24 days 27 days 20 days Neverlight Grove 16 days 16 days 24 days — 12 days 26 days Gracklstugh 19 days 20 days 27 days 12 days — 20 days Sloobludop 19 days 20 days 20 days 26 days 20 days — Chapter 3 - Navigating the Underdark A fast pace makes it harder to spot ambushes or items of interest and prevents the characters from foraging, while a slow pace allows the characters to travel stealthily enough to surprise or sneak past creatures they encounter and improves their chances of successfully finding food and water. The Underdark Travel Times table shows the time to travel between major Underdark locations. These times assume that the party moves at a normal pace without stopping (other than for time spent resting or becoming lost). For a fast pace, reduce the travel times by one third, for a slow pace, increase them by one third. Faerzress An unusual magical energy the drow call faerzress pervades much of the Underdark. The origin of this mysterious arcane power is unknown. Legend claims it is an ancient elven magic dating back to the time when the dark elves were first exiled from the world above. The drow and other Underdark creatures used the properties of areas suffused with faerzress to protect their settlements. Much of this faerzress was consumed as a catalyst for Gromph Baenre’s demon summoning ritual. What little faerzress remains has become tainted by the Abyss. Areas suffused with faerzress can range in size from a few dozen feet across to several miles in diameter and feature the following effects: • Areas suffused with faerzress are always filled with dim light. • A creature in an area suffused with faerzress has advantage on saving throws against any divination spells. If a divination spell doesn’t allow a saving throw, the caster must succeed on a DC 15 Constitution saving throw to cast the spell. Failing this save means the spell is wasted and has no effect.

CHAPTER 3 - NAVIGATING THE UNDERDARK | 23 • Any creature attempting to teleport into, within, or out of a faerzress-suffused area must succeed on a DC 15 Constitution saving throw. On a failed save, the creature takes 1d10 force damage and the teleportation attempt fails. Even if the save succeeds, the teleportation attempt can suffer a mishap as if the destination was known only by description, regardless of how familiar the destination actually is. See the table in the teleport spell for more information. • Areas suffused with faerzress have become tainted by the chaos of the demon lords. When a spell is cast in a faerzress-suffused area, the caster rolls a d20. On a roll of 1, the spell has an additional effect, determined by rolling on the Wild Magic Surge table in chapter 3, “Classes,” of the Player’s Handbook. Though faerzress can’t be dispelled, its effects are temporarily suppressed in the area of an antimagic field. Fungi of the Underdark The Underdark is home to a tremendous variety of fungi with a variety of different uses. Characters can encounter different examples of the Underdark’s flora in their travels. Identifying a species of fungi and its potential uses requires a successful DC 15 Intelligence (Nature) check, but Underdark inhabitants are familiar with many of these species automatically. With the coming of the demon lords, portions of the Underdark have become warped and corrupted, reflecting their Abyssal kingdoms. Because of this some of the fungi within the Underdark have become demon-tainted. Demontainted fungi can be detected by any character proficient in Nature who makes a successful DC 13 Intelligence (Nature) check. Barrelstalk A barrelstalk is a large, cask-shaped fungus that can be tapped and drained of the fresh water stored within it. A single barrelstalk contains 1d4 + 4 gallons of water and yields 1d6 + 4 pounds of food. Any creature that eats or drinks tainted barrelstalk must make a successful DC 10 Wisdom saving throw or experience disconcerting hallucinations for the next 24 hours. Previously solid features such as walls and floors begin to writhe and twist. Sounds are more guttural. And all colors take on a bruised, bluish-purple tinge. While hallucinating, the creature has disadvantage on all Wisdom checks and saving throws. Any character proficient with alchemist’s supplies may attempt a DC 15 Intelligence check to transform the liquid of a tainted barrelstalk into a potion of resistance (psychic). The barrelstalk and its contents are consumed during the process. Bigwig A bigwig is a four-inch-tall mushroom with a thin stem and a wide purple cap. A creature that eats one can choose to make a DC 12 Constitution saving throw to not be affected by the mushroom’s magic. If the creature fails or forgoes the saving throw, it grows in size as though under the enlarge effect of an enlarge/reduce spell. The effect lasts for 1 hour. Ten minutes before the effect ends, the creature feels a tingling sensation, at which point it can sustain its current size by eating another bigwig. The effect ends if the creature eats a pygmywort mushroom or is magically reduced to its normal size (using the reduce effect of an enlarge/reduce spell, for example). Bluecap Dubbed the “grain of the Underdark,” a bluecap is inedible, but its spores can be ground to make a nutritious, bland flour. Bread made from bluecap flour is known as sporebread or bluebread. One loaf is equivalent to 1 pound of food. Tainted bluecap is sweet to the taste, but difficult to digest and can induce nausea. Any creature that consumes tainted bluecap or something made from tainted bluecap must make a successful DC 10 Constitution saving throw or become poisoned for the next 24 hours. Regardless of whether or not they make their save, the creature has advantage on all saving throws against sporerelated effects for the next 24 hours. Fire Lichen Pale orange-white in color, fire lichen thrives on warmth, so it grows in regions of geothermal heat. Fire lichen can be ground and fermented into a hot, spicy paste, which is spread on sporebread or added to soups or stews to flavor them. Duergar also ferment fire lichen into a fiercely hot liquor. Tainted fire lichen burns with a demonic flame. Any character who comes into contact with it takes 2 (1d4) fire damage. Tainted fire lichen becomes harmless within an hour of harvesting, although any creature who consumes alcohol made from it must succeed on a successful DC 10 Wisdom saving throw or spend the next hour convinced that all nearby creatures are planning to attack them. Tainted fire lichen is prized by spell casters. It can be used as an optional spell component for spells that inflict fire damage. Spells augmented in this way inflict half damage on Fiends that have immunity to fire and regular damage on Fiends that have resistance to fire. Tainted fire lichen is consumed upon the casting of the spell.

24 | CHAPTER 3 - NAVIGATING THE UNDERDARK Nightlight A nightlight is a tall and tube-shaped bioluminescent mushroom that grows to a height of 1d6 + 4 feet and emits bright light in a 15-foot radius and dim light for an additional 15 feet. A nightlight that is uprooted or destroyed goes dark after 1 round. If a living nightlight is touched, either by a creature or an object, its light goes out until it is touched again. Tainted nightlights give off an ominous glow, casting strange shadows that seem to writhe with a life of their own. The true form of any Fiend standing within tainted nightlight is revealed, regardless of any magic that might be used to hide or disguise it. Nilhogg's Nose A Nilhogg’s nose is a small mushroom that grants any creature that eats it advantage on Wisdom (Perception) checks based on smell for 1d4 hours. However, the creature suffers disadvantage on saving throws against effects based on smell for the same amount of time. Any creature that consumes tainted Nilhogg’s nose gains darkvision for the next 24 hours. However, they also have a sensitivity to light. While in bright light, the creature has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight. Ormu A bioluminescent green moss that grows in warm and damp areas, ormu is particularly common near steam tunnels and vents. It sheds dim light in a 5-foot radius and can be harvested, dried, and made into a phosphorescent powder or pigment. Any Fiend standing within the glow of tainted ormu is affected by greater invisibility. Pygmywort A pygmywort is a mushroom with a 1-inch-long stem and a stubby blue cap with white dots. A creature that eats one can choose to make a DC 12 Constitution saving throw to not be affected by the mushroom’s magic. If the creature fails or forgoes the saving throw, it shrinks in size as though under the reduce effect of an enlarge/ reduce spell. The effect lasts for 1 hour. Ten minutes before the effect ends, the creature feels a tingling sensation, at which point it can sustain its current size by eating another pygmywort. The effect ends if the creature eats a bigwig mushroom or is magically enlarged to its normal size (using the enlarge effect of an enlarge/reduce spell, for example).

CHAPTER 3 - NAVIGATING THE UNDERDARK | 25 Ripplebark Ripplebark is a shelf-like fungus that resembles a mass of rotting flesh. It is surprisingly edible. Though it can be eaten raw, it tastes better roasted. A single sheet of ripplebark yields 1d4 + 6 pounds of food. Tainted ripplebark takes on a life of its own, slowly transforming itself into a moaning mass of rotting flesh. Transformed ripplebark has the same statistics as a gibbering mouther but with a movement speed of 0. Timmask Also known as the “devil’s mushroom,” a timmask is a two-foot-tall toadstool with orange and red stripes across its beige cap. Uprooting or destroying a timmask causes it to expel a 15-footradius cloud of poisonous spores. Creatures in the area must succeed at a DC 14 Constitution saving throw or be poisoned. While poisoned in this way, the creature is under the effects of a confusion spell with a duration of 1 minute. When the spell effect ends, the poisoned condition also ends. Tainted timmask is exceptionally virulent. Uprooting or destroying the mushroom causes it to expel a 15-foot-radius cloud of toxic yellow spores that lasts for 10 minutes. Any creature that enters the spores or starts its turn there must make a DC 16 Constitution saving throw. The creature takes 4d8 poison damage on a failed save, or half as much damage on a successful one. Creatures are affected even if they hold their breath or don’t need to breathe. Tongue of Madness Tongue of madness is an edible fungus that looks somewhat like a large human tongue. A creature that eats a tongue of madness must succeed on a DC 12 Constitution saving throw or compulsively speak aloud its every thought for the next hour. The effect can be ended with a lesser restoration spell or similar magic. Any creature that consumes tainted tongue of madness must succeed on a DC 14 Constitution saving throw or only be able to speak and understand Abyssal for the next 24 hours. Regardless of whether or not they make their saving throw, the creature has advantage on Charisma checks to influence Fiends for the next 24 hours. Torchstalk A one- to two-foot-tall mushroom with a combustible cap, a single torchstalk burns for 24 hours once lit. There is a 1-in-6 chance that a torchstalk explodes when lit, bursting into a cloud of fiery spores. Creatures within 10 feet of an exploding torchstalk take 3 (1d6) fire damage. Much like tainted nightlight, the flame of a tainted torchstalk emits a fiendish flame that casts bizarre, unnatural shadows. The flame burns brightly, lasting only for 1 minute. The illumination cast by the flame cannot be seen by fiendish eyes. Fiends cannot detect any creature standing within 5 feet of a lit torchstalk, unless they have truesight. Trillimac A trillimac is a mushroom that grows to a height of four to five feet and has a broad gray-green cap and a light gray stalk. The cap’s leathery surface can be cut and cleaned for use in making maps, hats, and scrolls (its surface takes on dyes and inks well). The stalk can be cleaned, soaked in water for an hour, then dried to make a palatable food akin to bread. Each trillimac stalk provides 1d6 + 4 pounds of food. Tainted trillimac is an Abyssal delicacy. Its stunted stalks provide only 1d4 pounds of food. Any Fiend (including tieflings) who consumes a quarter of a pound of tainted trillimac during a short rest gains 2d6 temporary hit points. Any creature proficient with cook’s utensils may attempt a DC 15 (Dexterity) check to make a thick, crusty wafer equivalent to a potion of healing out of one pound of trillimac. Waterorb A waterorb is a bulbous fungus that grows in shallow water. A mature waterorb can be squeezed like a sponge, yielding a gallon of drinkable water and a pound of edible (if chewy and somewhat tasteless) food. Tainted waterorb is corrupted by the influence of the River Styx. Unless its water is boiled, any creature drinking it must succeed on a DC 14 Intelligence saving throw or become afflicted by the feeblemind spell for the next hour. While under the effect of the spell, the creature can cast the divination spell as if reaching out to an archdevil. Such a communion can only occur once per day. Zurkhwood Zurkhwood is a massive mushroom that can reach a height of thirty to forty feet. Its large, grain-like spores are edible and nutritionally equivalent to 1d4 + 4 pounds of food, but Zurkhwood is more important for its hard and woody stalks. Zurkhwood is one of the few sources of timber in the Underdark, used to make furniture, containers, bridges, and rafts, among other things. Skilled crafters can use stains, sanding, and polishing to bring out different patterns in zurkhwood. Tainted zurkhwood attracts the attention of Undead creatures. Structures that have been built

26 | CHAPTER 3 - NAVIGATING THE UNDERDARK from tainted zurkhwood tend to be haunted by ghosts or other spectral apparitions. A creature proficient with woodcarver’s tools may attempt a DC 10 Dexterity check to carve a weapon from a block of zurkhwood. If successful, this weapon counts as magical when used against Fiends. Environmental Effects The prolonged invasion of the demon lords has corrupted more than just the fungi. The entire Underdark has buckled under the weight of their incursion. And, over time, the Underdark has slowly transformed itself into a blasphemous reflection of the Abyss. The following environmental effects are a powerful tool for showcasing this ongoing metamorphosis, particularly when coupled with travel encounters. Abyssal Foliage After his titanic battle with Baphomet, Yeenoghu was left near death’s door. The demon lord, stubbornly clinging to life, crawled his way through the Underdark, seeking a place where he might rest and lick his wounds. Along the way his dark, demonic blood watered the thirsty stone of the Underdark from which grew strange, alien foliage previously native only to the Abyss. Months later this foliage began to attract Beasts of all kinds – not only rothé, but fiendish versions of animals not normally seen within the Underdark such as warthogs and gazelles. These animals, in turn, have spread the foliage throughout the Underdark with their periodic migrations. To the naive, finding subterranean foliage can feel like a boon. Lush, phosphorescent fruits hang heavy from the vines and there is no shortage of game to be hunted. However, experienced travelers know to avoid these areas. Servants of Yeenoghu are alerted anytime a creature enters a shared patch of Abyssal foliage and can track such a creature unerringly. On top of this, the verdant overgrowth counts as difficult terrain for anyone who is not a servant of Yeenoghu. Cacklestorm Cacklestorms are an atmospheric phenomenon native to the Abyss that have begun to appear within the Underdark. They manifest as an unseen breeze of demonic laughter capable of drawing victims into its insane cacophony. The first sign of an impending cacklestorm is a soft giggling that seems to come from a dozen wicked voices. Hearing the faint tittering requires a successful DC 13 Wisdom (Perception) check. Those who succeed can quickly plug their ears to protect themselves, for in the next round the dozen voices become a hundred and then a thousand, until the caverns echo with a chorus of insane laughter. Anyone able to hear the cacklestorm must succeed on a DC 16 Wisdom saving throw or fall under the effect of Tasha’s hideous laughter spell lasting, at most, 1 minute. Demonic Faerzress Some of the remaining patches of faerzress have been corrupted by the influence of the demon lords. Demonic faerzress glows a dark, ominous red, and any creature caught within it for too long begins to grotesquely mutate. Any flesh-and-blood creature that spends 10 minutes within an area of demonic faerzress must make a DC 10 Constitution saving throw. Fiends, Oozes, Plants, and Undead automatically succeed on the saving throw. On a successful save, the creature does not need to make another saving throw for one day. On a failed save, the creature is magically warped by the faerzress, as determined by rolling on the Flesh Warping table. A spell that removes a curse ends all faerzress-related warping effects on a creature.

CHAPTER 3 - NAVIGATING THE UNDERDARK | 27 Flesh Warping Table d100 Effect 01-05 The color of the target’s hair, eyes, and skin becomes blue, red, yellow, or patterned. 06-10 The target’s eyes push out of its head on the end of stalks. 11-15 The target’s hands grow claws, which can be used as daggers. 16-20 One of the target’s legs grows longer than the other, reducing its walking speed by 10 feet. 21-25 The target’s eyes become beacons, filling a 15-foot cone with dim light when they are open. 26-30 A pair of wings, either feathered or leathery, sprout from the target’s back, granting it a flying speed of 30 feet. 31-35 The target’s ears tear free from its head and scurry away, the target is deafened. 36-40 Two of the target’s teeth turn into tusks. 41-45 The target’s skin becomes scabby, granting it a +1 bonus to AC but reducing its Charisma by 2 (to a minimum of 1). 46-50 The target’s arms and legs switch places, preventing the target from moving unless it crawls. 51-55 The target’s arms become tentacles with fingers on the ends, increasing its reach by 5 feet. 56-60 The target’s legs grow incredibly long and springy, increasing its walking speed by 10 feet. 61-65 The target grows a whiplike tail, which it can use as a whip. 66-70 The target’s eyes turn black, and it gains darkvision out to a range of 120 feet. 71-75 The target swells, tripling in weight. 76-80 The target becomes thin and skeletal, halving its weight. 81-85 The target’s head doubles in size. 86-90 The target’s ears become wings, giving it a flying speed of 5 feet. 91-95 The target’s body becomes unusually brittle, causing the target to gain vulnerability to bludgeoning, piercing, and slashing damage. 96-100 The target grows another head, causing it to have advantage on saving throws against being charmed, frightened, or stunned. Living Tunnels The destruction of a demon lord can reverberate for miles, scarring and twisting the land around it. Such was the case when Baphomet was slain by Yeenoghu. Remnants of his mortal form now infuse portions of the Underdark, turning what used to be straight passageways into a twisting maze of serpent tunnels that seem to coil and uncoil with a life of their own. Travelers are at the whims of the living tunnels, although occasionally this is advantageous. When a creature or group of creatures first enters the living tunnels, roll a d4. If the result is even then it takes that many more days for the creatures to reach their destination. If the result is odd then it takes that many fewer days for the creatures to reach their destination. Necrotic Zone The passing of Orcus and his minions has left pockets of necrotic energy interspersed throughout the Underdark. There are no visible features that accompany such a phenomenon, although the surrounding stone is unnaturally brittle and flakes to the touch, as if the ground itself was dead. Creatures who enter such an area experience a supernatural chill. The air is filled with the stench of rotting flesh and the sound of buzzing flies, although no carrion or insects can be found. Any spell from the necromancy school of magic that is cast within a necrotic zone is cast as if it is one level higher. Additionally, any living creature that dies in a necrotic zone rises in 1d4 rounds as a zombie (or, at the DM’s discretion, a more powerful Undead). Spells such as revivify still function normally and can even be cast upon newly risen zombies to break their curse of undeath and restore them to life. Necrotic zones tend to form beneath graveyards or ancient battlefields. In these cases the necrotic energy seeps into the soul, and the animated corpses begin tunneling downwards through the dirt, occasionally burrowing through the ceiling to surprise the unwary.

28 | CHAPTER 3 - NAVIGATING THE UNDERDARK Oozing Caverns When Juiblex was defeated by Zuggtmoy, the Faceless Lord split into an unknown number of Tiny Oozes that immediately hid within the innumerable cracks and crevices of the Underdark. Over time, these Oozes have spread throughout the Underdark. Always hungry. Always consuming. Most of these Oozes are now Huge and their chaotic meanderings leave trails of slime that can stretch for miles. This slime pools along the floor, clings to the walls, and drips from the ceiling, eating its way through flesh, armor, and magic. For every ten minutes spent within an oozing cavern, a creature must succeed on a Dexterity saving throw (the DC of which varies) or suffer one of the following randomly selected effects: • Suffer 10 (2d10) acid damage. • Any armor or shield carried by the creature takes a cumulative −1 penalty to its AC. This effect can be reversed by anyone proficient with smith’s tools who spends an hour to do so. • One spell or magical effect on the creature is ended. Any character can spend 10 minutes to attempt a DC 12 Wisdom (Survival) check to harvest some samples of slime. In the event of a success, the character obtains 1d6 vials of slime that are mechanically equivalent to vials of acid. Only one attempt may be made for every half mile of oozing caverns. Spore Clouds Now that Zuggtmoy is successfully fused with Araumycos, she is rooted to a single location. However, her reach still extends into the far corners of the Underdark, thanks to the clouds of spores that she has dispersed far and wide. Clouds of microscopic spores are barely visible as a hazy, indistinct wavering in the air. Should a living creature step into a cloud its eyes begin to water, mucus wells up in its nose, and it begins to sneeze uncontrollably as its body attempts to fight off the foreign particles. Any flesh-andblood creature exposed to these spores must make a Constitution saving throw (DC varies). On a successful saving throw, the creature can’t be infected by the same spore cloud for 1 day, or any other source of spores for 1 minute. On a failed save, the creature is infected with a disease known as the spores of Zuggtmoy. While infected in this way, the creature can’t be reinfected. The creature is incapacitated, spending its turn coughing and vomiting. At the end of each of the creature’s turns, it must repeat the saving throw, ending the effect on a success. A creature that fails three of the saving throws consecutively stops making these saving throws, is no longer incapacitated, and is enslaved to the will of Zuggtmoy, shambling its way unerringly toward Zuggtmycos. This effect can be removed by any effect that cures diseases, such as the lesser restoration spell. It is left to the DM’s discretion as to how the infected creature might best serve the will of Zuggtmoy.

CHAPTER 3 - NAVIGATING THE UNDERDARK | 29 Narrating the Journey As the adventurers make their way through the Underdark, it helps to improvise descriptions of what they experience to add flavor to the journey. As you do, try to stress two key points. First, the trek is long and arduous. The party is traveling underground, over incredibly difficult and rough terrain, without any of the comforts of the surface world. Food and water are scarce. The darkness never ends. The players should feel as though their characters are in peril throughout their travels, never knowing when something is set to leap at them from the shadows. Second, the demonic Underdark is an exotic alien landscape unlike anything found on the surface world. Throughout its twisted passageways and impossibly large caverns, characters might find bizarre reminders of lost and forgotten civilizations, unearthly flora and fauna, and incredible geography. Little is as it seems, and much is difficult to explain, or even to describe. Travel Encounters Tables of random encounters can be found in both the Dungeon Master's Guide and Out of the Abyss. To supplement these, we include another table that emphasizes the unique nature of the Doomed Underdark that can be used during your characters’ travels. Travel Encounter Table d10 Encounter 1 Angel 2 Black Dragon 3 Drider 4 Drowgar 5 Elemental Cultists 6 Hell Riders 7 Hidden Tombs 8 Kuo-toa 9 Minotaurs 10 Vegepygmies Angel Recently a deva was dispatched to the Underdark to investigate rumors of petrified celestials. Most worrisome were the rumors that Zariel was restoring these fallen angels and recruiting them to fight for her in the Blood War. The deva was ambushed by a nalfeshnee and two vrocks. She was able to kill both vrocks before being knocked unconscious by the nalfeshnee. The demon has now pinned the deva’s wings to the wall of a cavern with a pair of rusted spears and is preparing to torture her. The deva is at 0 hit points and the nalfeshnee only has 60 hit points. If the characters free the deva, then she is grateful, offering to cast commune or raise dead on their behalf. In her weakened state she must return to Mount Celestia so she asks the characters to finish her quest for her. If they agree she gently touches each character’s forehead and gives them a flask of liquified redemption. The characters now always know the most direct path to the petrified angels. The petrified celestials can be found within the Labyrinth in a cavern known as the Gallery of Angels. There were once eight such angels, however Zariel has restored and corrupted four of them. The remaining four are guarded by an erinyes known as Lord Azalyth. If the characters manage to place a drop of sacred water upon the stony bosom of a petrified angel then they are restored and redeemed. The angel aids the character in fighting any devils before dissipating into a cloud of golden motes as they return to Mount Celestia. If the characters restore all four remaining angels then whichever one of the characters most embodies the principles of lawful good receives a Blessing of Health (see chapter 7 of the Dungeon Master’s Guide). Black Dragon A young black dragon named Xzandulgal, driven by visions from Tiamat, seeks out Gracklstugh. She is accompanied by a retinue of six kobolds. These groveling servants struggle under the weight of the dragon’s hoard, a bulky collection of coins, chalices, and gemstones worth 1,000 gp in total. In return for not devouring the characters, Xzandulgal demands to be led to Gracklstugh so that she can help claim the city in the name of the Dragon Queen. If the party refuses the dragon's offer, she fights them in an incredulous rage, but retreats when reduced below half hit points, swearing vengeance. If the party leads the dragon to Gracklstugh they find themselves welcomed into the city by members of the Cult of the Dragon. The cultists bestow upon the characters two items of their choice from Treasure Table C of the Dungeon Master's Guide. The characters are welcomed warmly while in the city, however the Deepking resents the shift in political power and sends duergar assassins to kill the characters if they stay for more than two days.

30 | CHAPTER 3 - NAVIGATING THE UNDERDARK Drider The characters are ambushed by a drider known as Jorlan Duskyn. Jorlan was once a commander of the drow outpost Velkynvelve (consider using an unnamed generic drow outpost if you do not want your characters to travel too far), but was cursed by Lolth to become a drider after betraying one of her priestesses. His face is hideously disfigured and his right hand is mangled and malformed, deformations he received from a run-in with a black pudding. His goal is to capture the characters alive and then force them to venture into Velkynvelve to retrieve a small shrine to Lolth that has sentimental value to the drider. If reduced to less than a quarter of his hit points the drider gives up, instead offering to tell the characters about a secret cache of treasure in Velkynvelve if they agree to retrieve the shrine. The drow outpost is now home to four chasme demons. The small shrine to Lolth can be found in the abandoned quarters of the high priestess. It is carved of zurkwhood and bone, inlaid with semiprecious stones, and worth 50 gp. Also within the quarters is a hidden chest that can be found with a successful DC 15 Intelligence (Investigation) check. This is the secret cache of treasure mentioned by Jorlan and is found automatically if he mentioned it to the characters. The chest is unlocked but trapped with a poison needle trap (see chapter 5 of the Dungeon Master’s Guide). If the characters are carrying any demonic containment stones (see chapter 6 area B19) then they begin to glow after the demons are slain. Jorlan cries with ecstatic happiness if the characters return the shrine, telling them it once belonged to his long lost love Mistress Ilvara. Before parting, the drider warns the characters to avoid the Silken Paths, providing the characters with much of the information contained on this locale contained in chapter 2. Drowgar The characters hear the sounds of battle from a nearby cavern. Should they investigate the find a Zhentarim mage and four duergar preparing to chop off the head of what looks to be a bound drow. If the characters do not intervene, the duergar kill the drow and sever his head, planning to bring it to Mantol-Derith for a bounty (see chapter 6, area B1). If the characters reveal themselves, one of the duergar turns invisible and flees, while the others fight. If the duergar flees successfully, they might return to harry the characters either as another travel encounter or while they are visiting Gracklstugh. The drow looks unusual upon close examination. He has the features of a drow except for a flattened nose, reminiscent of the duergar, and a thick beard of pure white hair. His name is Aungar Mij and he is not actually a drow but, rather, a drowgar. Drowgar is a term given to those whose ancestry involves both duergar and drow. Aungar is fiercely loyal to the characters should they save him. His parents (a drow mother and duergar father) were killed when he was young. Before they died, they told Aungar of a hidden settlement of reclusive drowgar and Aungar now spends his days searching for it. Aungar is a priest of Unilessa, a goddess of life and harmony. In thanks to the characters he is willing to cast four priest spells of up to 3rd level for them. He can also inform the characters about the drow’s fall from grace, as described in the sections on Mantol-Derith and Menzoberranzan. For more information on how you might integrate the drowgar into your campaign see Secrets of the Drowgar by Splinterverse Media. Elemental Cultists The characters pass through a section of dormant volcanic rifts. Encamped within this area are six cultists of the Elder Elemental Eye, led by a cult fanatic. The cultists are accompanied by a bickering pair of mephits (one ice mephit and one magma mephit). The cultists have been tasked with reigniting the rifts. Doing so will thaw out some frozen earth above, allowing the surface dwellers who have hired the cultists to grow their crops. Any character who makes a successful DC 15 Intelligence (Arcana) check realizes that the rifts can be reignited through a specific ritual that culminates with the casting of any spell that deals fire damage into the rifts. The spell must be cast using a 3rd level spell slot. Alternatively the cultists know that the ritual can be completed using the heart of a flame basilisk. The cultists know that a flame basilisk lairs nearby and it can be tracked down by a successful DC 15 Wisdom (Survival) check. A flame basilisk has the same statistics as a basilisk except that it has immunity to fire damage, vulnerability to cold damage, and does an additional 1d6 fire damage with each of its attacks. The cultists carry with them four vials of pure elemental water. These vials are worth 100 gp each to an alchemist and are coveted by water elemental creatures such as Arqtanis from area B13 in chapter 6. The cultits give the vials to the characters if the characters manage to successfully ignite the dormant rifts. The cultists can also provide directions to the Elemental Chaos (see chapter 2) as well as the surface world.

CHAPTER 3 - NAVIGATING THE UNDERDARK | 31 Hell Riders The characters come across a chasm spanned by a narrow, natural bridge of stone. At the end of the bridge is a cavern in which four knights in devil bone armor are trying to repair an infernal vehicle. The knights are Hell Riders who have been dispatched by High Rider Ravengard to hunt down and kill a legion of bone devils sighted in the area. The infernal vehicle is referred to as the Celestial Tunneler and it looks like a tank with a large drill. The Tunneler has currently broken down and the Hell Riders need replacement parts to fix it. The Hell Riders know of some clockwork automatons in the area and ask the characters to seek them out, destroy them, and bring back their bodies to be used as spare parts. If the characters seek out the automatons then they are soon ambushed by two clockwork bronze scouts and a clockwork cobra (see appendix B) that burst forth from the wall of a nearby tunnel. The automatons are under the control of Tixie Tockworth, a deep gnome cyborg who has conquered the nearby svirfneblin city of Little Lockford. They are programmed to kill any Humanoids they come across and bring the dead bodies back to Little Lockford to be used as part of Tixie’s clockwork flesh experiments. If the characters return with automaton scrap, then the knights quickly finish their repairs. The Hell Riders offer the characters a ride in the Celestial Tunneler to their destination of choice. If the characters take them up on this offer then they reach their destination in half the usual time. Additionally, the Hell Riders can provide all the information on the Fardrimm provided in chapter 2. Hidden Tomb You can also use this encounter as the destination of a discovered treasure map, such as the one found in area B3 of chapter 6. The characters discover a small crevice that looks as if it was created by recent seismic activity. Exploring the crevice reveals a finished stone hallway. The walls of the hallway are covered in ancient writing. The writing can be read by any character fluent in Abyssal. It indicates that the hallway leads to a temple of Obox-ob, the Demon Prince of Vermin. The hallway leads for one hundred feet before becoming blocked by rubble. Shortly after reaching the rubble a friendly xorn emerges from the wall. This unique xorn, who goes by the name Sparkleguts, learned to speak Common and Undercommon so that it could negotiate for gemstones with humanoids. It was attracted to the temple by the scent of gemstones. However, it realizes that the temple might be guarded. Because of this it proposes an alliance with the characters. The xorn offers to clear the rubble leading to the temple, as long as the characters allow the xorn to have any gemstones found within. If the characters agree to this deal then the xorn spends the next two hours clearing away the rubble. Behind the rubble is a set of stone double doors covered in more writing glorifying the demon lord Obox-ob. The stone doors are heavy and sealed with mold, but can be opened by any creature that makes a successful DC 15 Strength check. Once the doors are opened dozens of swarms of insects and swarms of rats surge forth. These swarms are focused on escaping the temple, and fight only in self defense. The temple consists of a single chamber that is hundreds of feet wide. It is filled with huge, obscene statues of bestial vermin that are only vaguely recognizable. As the characters explore the chamber Sparklegut lets out a loud scream as a creature resembling a spider with mandibles drops from the ceiling and quickly burrows into the xorn’s body. The spider creature is an ancient being from long ago known as an oboxian. Within seconds it takes over the xorn’s body, speaking through its mouth as it demands that the characters sacrifice themselves to Obox-ob. In the face of resistance it fights to the death, using the same statistics as a xorn but with the Spellcasting trait of a mage. Searching through the vast temple is a time consuming task. However, characters that do so discover 2d6 gemstones worth 50 gp each and a randomly determined magic item from Magic Item Table G in the Dungeon Master’s Guide. At the DM’s discretion some oboxians may have escaped the temple, hidden amidst the escaping swarms.

32 | CHAPTER 3 - NAVIGATING THE UNDERDARK Kuo-toa Precede this encounter by having the characters first discover a deep, slow-moving underground river. Their route soon takes them away from the river and four hours later the characters cross paths with a tribe of one hundred kuo-toa, ten kuo-toa whips, led by Blopbloopblip, a kuo-toa archpriest. The kuo-toa are on a pilgrimage to Sloobludop. It has been days since they have had water and they are nearly dead from dehydration. Because of this they fight only in self defense. If the characters lead the kuo-toa to the nearby river, the fishlike Humanoids are overjoyed, splashing around like children while praising Leemooggoogoon. Two rounds later, ten merrow emerge from the water, attacking the surprised kuo-toa. Blopbloopblip uses his powers to successfully combat five of the aquatic ogres. However, each of the five remaining merrow attempts to grapple a kuo-toa before diving back into the river to drag the hapless captive through the half mile of submerged tunnels that lead back to its lair. Regardless of how the merrow raid plays out, the kuo-toa are grateful to the characters for leading them to the river. The amphibious creatures are willing to share all of the information regarding Sloobludop contained in chapter 2. If the characters prevented any kuotoa from being abducted then Blopbloopblip calls upon the power of Leemooggoogoon to bless two flasks of river water, turning them into potions of water breathing. The characters can also bring word of this kuo-toa procession to Durloth and Dansy (see area B11 in chapter 6), for a possible reward. Minotaurs The characters enter an area of living tunnels (see the section on Environmental Effects) occupied by a family of five minotaurs. Shortly upon entering the tunnels, the characters come across Baron Duxle, a fast-talking goblin merchant. Baron Duxle sells food and water out of a rickety wagon. The wagon is pulled by an enchanted, pink-furred deep rothé (appendix B) called Pinky. Mushrooms and other fungi magically grow within Pinky’s manure, which is how Baron Duxle gathers his provisions. Baron Duxle is terrified of the minotaurs, and begs the characters to help him escape the living tunnels before they are discovered. The goblin promises to provide the characters with a map of secret Underdark tunnels if they agree to help. The characters’ guide must make a successful DC 15 Intelligence (Survival) check to escape the maze before they are found and attacked by the minotaurs. Baron Duxle honors his deal if safely escorted from the tunnels. The goblin merchant offers to draw a map connecting any two destinations of the characters’ choice. Characters using this map cannot become lost, do not have any random encounters, and reach their location one day sooner than normal. Vegepygmies The characters enter a great, terraced cavern. Large trees with huge red leaves the size of a human grow from the floor, and curtains of undulating vines hang from the ceiling. Forty vegepygmies live within the cave, worshiping a rotroots (see appendix B for both creatures). The rotroots currently has no demonic cadavers. Because of this it has become aggressive, attacking and killing the vegepygmies. The vegepygmies need some demon corpses to placate their god. The vegepygmies are friendly if approached by the characters. The small Plants are openly fascinated by the characters, poking and prodding them curiously. If communication is established, the vegepygmies explain their problem to the characters, asking them to visit a nearby chasm occupied by a barlgura and ten dretches. The Plant creatures want the characters to slay the demons and bring back their corpses (the demon corpses do not disintegrate as they normally would, due to Lolth’s Demon Web, as described in chapter 1). If the characters are successful, then the vegepygmies rejoice, inviting the characters to attend a prolonged religious ceremony that culminates with an offering of the corpses to the rotroots. After the ceremony the vegepygmies give the characters directions to a nearby fungal thicket. Those searching the thicket find 2d6 bluecaps, 1d4 Nilhogg’s noses, 1d4 tongues of madness, and 1d6 bigwigs. There is a 20 percent chance that any particular type of fungus is demon-tainted. See the Fungi of the Underdark section, earlier in this chapter, for more details.

CHAPTER 4 - RAMPAGE | 33 Chapter 4 - Rampage C hapters 4 through 9 comprise an Underdarkthemed adventure centered around stopping the spread of the Demon Queen Zuggtmoy’s demonic spores. The adventure is intended for three to five characters. The characters should be 1st level when they begin the adventure, and will reach 7th level by the time they thwart Zuggtmoy’s sinister plans. Although the adventure has been designed to be played in its entirety, each chapter has been written so that it can be played as a stand-alone story. Most of this content can be integrated into Out of the Abyss, as desired, with very few changes. It can also be integrated into Rise of Vecna. In this case, the main quest giver from chapter 6, Wyloth, can be an agent of the Resistance who eventually directs the characters to Xanathar’s hidden base of operations beneath Thornhold. In this first chapter of the adventure the characters are visiting Zymorven Crossing, a Zhentarim trading outpost. While they are visiting, a raiding party of gnolls, using an enslaved purple worm, triggers a collapse within the center of the settlement. The characters are tasked with a number of smaller missions by the Red Wyvern, leader of Zymorven Crossing. Their last task involves liberating the purple worm from its demonic subjugation, an event that ultimately leads to the rout of the invading gnoll party. Zymorven Crossing The adventure begins within a Zhentarim outpost known as Zymorven Crossing, however it should be easy to adapt this beginning to any other small fortified outpost or village. Zymorven Crossing is a walled military community about fifty miles south of Mithral Hall. Only a few miles north of Zymorven Crossing can be seen Zymorven Hall, a keep of mortared stone perched atop a lone crag that overlooks Rauvin Road. Zymorven Hall is strategically important because it contains the most easily accessible trade route to Mantol-Derith, a subterranean trading hub secreted within the depths of the Underdark (see chapter 6 for more details). Merchants hoping to travel to Mantol-Derith must first pass through Zymorven Crossing, where they are assessed a trading tariff before passing on to the keep’s accessway. It is recommended that the characters begin the adventure in a small tavern within Zymorven Crossing known as the Fallen Giant. The Fallen Giant is a large, unremarkable establishment primarily frequented by mercenaries. A battered greatsword hangs behind the bar, a nonmagical replica of the legendary Giant-slaying blade wielded by the deceased Lord Zymorven. The tavern is run by Kito Sandeth, a balding elderly man with wisps of red hair. The tavern is known for its tepid ale and barely edible spiced, fried potatoes. The characters might be visiting the Fallen Giant for any number of reasons. One such reason might be that they just finished escorting a caravan to Zymorven Crossing and are now looking for a new job. Depending on the group’s preference, the characters may or may not already know one another. Beginning the Adventure Allow the characters an opportunity to roleplay amongst themselves, especially if meeting for the first time. The characters can also roleplay with their fellow patrons, although most of them are sullen mercenaries looking for work. In the corner of the tavern, a handful of elves play a game of social deduction known as the Eyes of Vecna. In the Eyes of Vecna players are dealt seven cards representing various secrets. Players take turns rolling dice that can be used to gain insight into other player’s hidden cards. The first player to correctly guess all seven secrets of any other player wins the game. Use opposed Intelligence checks to determine the winner of any given game. Once the characters have had a chance to get settled in, read or paraphrase the following: You are interrupted by a deafening boom from outside the tavern. The ground beneath you then lurches suddenly. Tables and chairs fly everywhere, throwing patrons to the floor. There is the sound of shattering glass and splintering wood. Gusts of dirt and dust are blown in through open windows, coating everything and everyone. There is a moment of stunned silence during which everyone looks about, speechless and dumbfounded. This moment is short-lived, however, as you soon hear what sounds like hundreds of bestial howls merging together into a whooping dirge of deranged laughter from outside the tavern.

34 | CHAPTER 4 - RAMPAGE The howls come from a war party of gnolls that have used an enslaved purple worm to collapse a sinkhole within the center of the walled outpost, a mere hundred feet from the tavern. These gnolls, along with a contingent of ghouls and leucrotta, are now streaming forth from the sinkhole, intent upon slaughter. Repelling the Gnoll Incursion Once the characters emerge from the tavern, read or paraphrase the following: The air outside is filled with a choking cloud of dust that blots out the sun. About a hundred feet away you can see what looks to be a massive sinkhole that has opened up within the middle of the outpost. Scores of mangy-furred Humanoids with the faces of hyenas scramble up from the sinkhole with a loud, whooping cackle. Nearer to you is a human woman in full plate armor brandishing a greatsword. She yells loudly, “Regiments one, three, and five hold the perimeter! All others report here for orders! Now! Now! The Zhentarim will not be brought down by this pack of rabid curs!” The woman is known as the Red Wyvern and she is the commander of Zymorven Crossing. She is small and squat, looking almost dwarf-like. Her hair is completely shaven and she has piercing crimson eyes from which she takes her name. She has the statistics of a mage except that she has an AC of 18 (plate armor) and a Greatsword melee attack. If the characters approach her she immediately barks out orders, “We are missing the second and fourth regiments! You can find their barracks to the north! Head there and tell them to get their butts over here immediately!” The Red Wyvern then moves on to yelling orders to the troops around the edge of the sinkhole, speaking tersely to the characters only if necessary. Traversing the Battlefield Below are some sample encounters that can be used to add color and context to the rampant pillaging taking place. Raiders. Two gnolls and two hyenas charge recklessly down the road, looking for victims. If the characters have been moving cautiously, then allow them a DC 10 group Dexterity (Stealth) check to avoid notice. Otherwise, the gnolls attack the characters, screaming the word “YEENOGHU!!” every time they strike. Death from Above. As the characters are traveling through the outpost, they hear a gurgling scream and notice a nearby mercenary (same statistics as a guard) shot down by an arrow. The mercenary has been reduced to 0 hit points and is dying. Looking about, the characters notice two gnolls, wielding longbows perched atop a building twenty feet away. The gnolls then begin shooting at the characters. The building is fifteen feet tall and can be scaled by a character making a successful DC 13 Strength (Athletics) or Dexterity (Acrobatics) check. If the characters manage to revive the mercenary, she asks to join their group and fights by their side for the remainder of the rampage. Gravediggers. The characters pass a small memorial dedicated to Lord Harthos Zymorven. A ghoul has dug up the lord’s desiccated remains and is in the process of feasting upon them. The ghoul is intent upon its feast and ignores the characters. If the characters stop and slay the ghoul, the ghost of Lord Zymorven manifests briefly to express its gratitude. Each character gains inspiration and for the next 24 hours have advantage on all attack rolls made against any creature that has a larger size category. A Wolf in Sheep’s Clothing. The characters hear childish cries for help from behind a nearby building. The cries are made by a leucrotta (appendix B) posing as a child, which can be determined by any character who makes a successful DC 14 Wisdom (Insight) check. Should the characters investigate, the leucrotta attacks them with just a single Bite attack, hoping to drag out combat for its own sadistic joy. After two rounds of combat a nearby veteran joins the fray, yelling for the characters to continue with their mission while he vanquishes the creature. Burning It All to the Ground. The characters pass a building that has just been set aflame by passing gnolls. A large cart has been wedged

CHAPTER 4 - RAMPAGE | 35 against the door of the building, preventing its occupants, two commoners, from escaping. Any character who makes a successful DC 10 Wisdom (Perception) check notes a nearby well. If the characters are quick to act, the flames can be extinguished before they grow out of control. Alternatively, the characters can move the broken cart with a successful DC 13 Strength (Athletics) check. Task 1: Rallying the Barracks When the characters reach the guard barracks they find it barred shut from the inside. Within can be found twenty guards led by a cowardly veteran known as Spindle Kain. Spindle is unwilling to open the door and join the fray, yelling through the door, “Why should we’s go risking our necks, especially when there’s nothing to be gained from it?” Attempts made to persuade or coerce the guards into leaving the barracks and reporting to the Red Wyvern have a DC of 13. Such attempts are automatically successful if accompanied by promises of payment. After combat, the Red Wyvern is willing to pay 1 gp to each soldier; however, Spindle tries to get the characters to agree to 2 gp per soldier. In the event of unfulfilled promises, Spindle harbors ill will toward the characters. See chapter 5 for possible consequences. Conclusion. Once the characters return to the Red Wyvern, regardless of whether or not they were successful, she yells at them, “There’s no end to these damn gnolls! For every one we kill, two more take its place! We’re going to need help if we’re going to make it out of here alive! Go to the southern bell tower and ring the bell to alert the garrison at Zymorven Hall!” Task 2: Ringing the Bell The bell tower is a short trek from the tavern. It is an old stone tower. From its cracked exterior it is obvious that it has been damaged by the recent seismic activity. Outside of the tower four hyenas can be seen feasting on some fresh corpses. Any character that makes a successful DC 13 Intelligence (Arcana) check knows that it is possible for hyenas to transform into gnolls after gorging themselves upon slain creatures. The cowardly hyenas flee if confronted, but otherwise leave the characters alone. The bell tower has four stories, each of which must be traversed before reaching the top of the bell tower. Upon reaching the third floor, allow each character to make a DC 10 Wisdom (Perception) check to note that the floor looks unstable. Any character that crosses the floor has a 25 percent chance of falling through, taking 1d6 bludgeoning damage in the process. Any character who makes a

36 | CHAPTER 4 - RAMPAGE successful DC 12 Intelligence (Investigation) check discerns a structurally safe route across the floor. The bell can be easily rung once the characters reach the top of the tower, its thunderous gong echoing loudly throughout the tower. If the characters left the hyenas unmolested, then they have transformed into gnolls by the time the characters return. Their orange fur is matted with fresh, sticky blood and they whoop loudly as they attack the characters. If the characters were successful in their first task then they are immediately assisted by two nearby guards from the second regiment. Conclusion. Once the characters return to the Red Wyvern, regardless of their success, she screams at them, “It’s no use! There’s too damn many of them! We need to fight smarter, not harder! Go to my manor over on the western perimeter! Grab me the snuff box from the mantle in my study! No matter what you do, do not open it! Go! Go now, damn it!” Task 3: Gathering Supplies The Red Wyvern gives terse directions to her manor which is a large cottage built against the outpost’s wall. Two wounded veterans stand guard but allow the characters to pass if they indicate they were sent by the Red Wyvern. The interior of the manor is richly furnished but otherwise unremarkable. It is easy enough to find the study, however defensive wards have been recently activated and there is currently no gravity within the room. This is evident to those looking into the room as small objects such as books and plates can be seen bobbing in midair. Any creature who enters the room floats two feet above the floor and is unable to move unless they have fly speed. The mantle is at the far end of the study, fifteen feet from the entrance. A mahogany snuff box can be seen floating above the mantle within a jumble of floating books. The snuff box is light and can be obtained by spells such as mage hand, creatures with flight, or a rope and grapple. Alternatively, any character who can long jump 15 feet can jump far enough into the room to reach the mantle. The snuff box is protected by a glyph of warding. The nearly invisible glyph can be found with a successful DC 15 Intelligence (Investigation) check. If opened by anyone other than the Red Wyvern, the snuff box triggers the explosive runes effect. Each character within a 20-foot-radius of the snuff box must make a successful DC 15 Dexterity saving throw. The character takes 5d8 thunder damage on a failed saving throw, or half as much damage on a successful one. At this level this has a high likelihood of reducing the entire party to 0 hp. In this case, allow them to be revived by a passing soldier. The snuff box appears to be empty but is functionally equivalent to a bag of holding. Its contents include a wand of levitation (appendix C), a necklace of fireballs with two remaining beads, and a special spell scroll (see below). These items can be accessed by anyone, such as the Red Wyvern, who knows the secret command word. Conclusion. When the characters return, the Red Wyvern empties the snuff box, handing over its contents to the characters. If the characters were unable to recover the snuffbox, then she pulls the scroll out of a pouch and hands it to them. After briefly describing what she has given the characters, she yells, louder than ever, “My scouts tell me that the gnolls have a captive purple worm within the sinkhole. That must be what they used to create this collapse! A smarter foe would have fortified this asset but these bloodthirsty brutes have left it nearly unprotected! It’s time for us to take advantage of that! I need you to sneak into the sinkhole! Read this scroll when you are near the purple worm! It’s a powerful spell known as Vecna’s disjunction that will destroy whatever enchantments are keeping it enslaved, and hopefully create a little chaos in the process!” Task 4: Into the Sinkhole The 100-foot-deep sinkhole is initially 200 hundred feet in diameter, although it narrows the further down it goes. Descending through the rubble is difficult, but as long as the characters are cautious it does not require any checks. The sinkhole is largely vacant, as most of the frenzied gnolls have charged into the settlement. Two packs, each consisting of six gnolls and one gnoll pack lord, patrol the interior of the sinkhole. If the characters take time to observe their predictable patrol pattern, they can be easily avoided. Otherwise, the characters must make a successful DC 13 group Stealth check to avoid their notice. When the characters reach the bottom of the sinkhole they come across a tiefling merchant (commoner) pinned beneath an 800-pound wooden beam. If the merchant notices the characters, he gestures quietly for help. The beam can be moved enough for the merchant to escape if a character makes a successful DC 15 Strength (Athletics) check. If the characters prove either unable or unwilling to help, the merchant yells loudly. There is a 50 percent chance each round that the merchant’s shouts attract the attention of a gnoll patrol. The bottom of the sinkhole is strewn with rubble and the wreckage of shattered buildings and counts as difficult terrain. The purple worm is coiled within the center of the sinkhole. An iron collar has been bolted along its segmented body near its maw. The collar is engraved with glowing

CHAPTER 4 - RAMPAGE | 37 sigils of a triple-headed flail. Similar sigils, oozing infected pus and fresh blood, have been branded across the creature’s hide. Although currently docile, the purple worm can be seen shuddering occasionally in obvious pain. Conclusion. The worm remains passive, even if attacked. Should any character read the spell scroll of Vecna’s disjunction within twenty-five feet of the purple worm, then the collar glows brightly before exploding. Shortly thereafter the scroll is consumed in flame. The purple worm roars in rage and begins surging through the sinkhole. It ignores the characters but swallows whole any remaining gnoll patrols. Yelps of alarm begin to echo first from the sinkhole, and then into the outpost. The gnolls, interpreting the purple worm’s attacks as a sign of Yeenoghu’s displeasure, begin to fall back and flee, disappearing into small caverns within the side of the sinkhole. Within five minutes all the remaining gnolls have fled and Zymorven Outpost becomes deathly quiet. Conclusion With the retreat of the gnolls, the Red Wyvern gets to work dealing with the aftermath. She efficiently sets up guards throughout the sinkhole while setting up a number of field hospitals to deal with the wounded. As busy as she is she has few words for the characters. However one of her underlings, a bespectacled dragonborn known as Simeon, thanks the characters on her behalf. If any of the characters are affiliated with the Zhentarim, then they gain three renown. If they are not affiliated with the Zhentarim, then they are offered membership. The characters are given a secret passphrase, “Everything has a price,” that they can use to indicate their faction membership to other members. Additionally, the party is awarded 100 gp. Simeon also requests that the characters return the wand of levitation and any unused beads from the necklace of fireballs. Should the characters attempt to deceive him, he has an Insight bonus of +7 and is not above having the characters briefly detained, physically searched, and magically interrogated if he suspects they are attempting to steal from the Red Wyvern. Allow the characters to advance to 2nd level before proceeding to chapter 5. Sinkhole

38 | CHAPTER 5 - OF MUSHROOMS AND MALICE Chapter 5 - Of Mushrooms and Malice With the conclusion of the gnoll raid, it is noted that expected reinforcements from nearby Zymorven Hall never arrived. The characters are tasked with investigating Zymorven Hall. While there the characters discover a mysterious rift, opened by the gnolls’ recent seismic activity. Unbeknownst to the characters, spores of Zuggtmoy burst forth from this rift when it opened, enslaving the guards garrisoned within Zymorven Hall. The characters slowly figure this out as they explore the fungal grotto beyond the rift. After finding and slaying the evil myconid sovereign who rules the grotto, the characters report their findings to the Red Wyvern. Introduction After the characters have an opportunity for a long rest, they are contacted by Simeon. The dragonborn requests that the characters visit the Red Wyvern at her command center which has been recently established within the tavern. Once the characters arrive at the command center, read or paraphrase the following: The Red Wyvern acknowledges you with a curt nod. Immediately afterwards Simeon begins speaking, “As you may or may not be aware, Zymorven Crossing is strategically important because it guards access to the Underdark, a vast underground kingdom that exists beneath our very feet. More importantly, this accessway leads to a trading outpost known as Mantol-Derith. Controlling surface world access to Mantol-Derith has proven to be quite lucrative for the Black Network.” Simeon continues, “There are dangers, of course. Years ago the drow summoned a number of demon lords into the Underdark, creating widespread chaos and destruction. One of these demon lords is Yeenoghu, the Lord of Gnolls. We are used to dealing with his raiding parties, and although they have never been quite so creative before, we have no reason to believe that this is anything more than a random attack. That said, there has been a worrisome development. At this the Red Wyvern cuts Simeon off, yelling unnecessarily, “The soldiers from Zymorven Hall never came when you rang the bell! We need you to go there and find out why! If you come across any threats you are required to eradicate them with extreme prejudice!” The characters can obtain the following relevant information from Simeon: • Zymorven Hall is a keep of mortared stone perched atop a lone crag that overlooks Rauvin Road. It is almost two miles north of Zymorven Crossing. • The keep has been abandoned over the years. • The tunnel into the Underdark is located at the base of the crag, beneath the abandoned keep. It is blocked by a gate and protected by a garrison of twenty soldiers. • The Red Wyvern wants the characters to find out what happened to the soldiers. If the characters do this and completely eradicate any threat, then she is willing to reward them with 200 gp. Zymorven Hall A well-traveled paved road leads from Zymorven Crossing to Zymorven Hall. The journey is most likely uneventful. However, if the characters angered Spindle Kain (see chapter 4), then the veteran and two guards use this opportunity to ambush the characters, demanding that they hand over all of their money. If the characters refuse, then the Zhentarim soldiers fight to the death. When the characters reach the base of the peak, they find that the massive double doors leading into the Underdark have fallen out of place, allowing Medium sized creatures entrance to the tunnel beyond. Any character who makes a successful DC 10 Intelligence (Investigation) check discerns that the gate was likely broken by the recent seismic disruption. Beyond the broken doors can be found a large tunnel leading downwards into the Underdark. It is broad enough to comfortably accommodate two wagons side-by-side. Stalagmites, stalactites, and all other rock formations have been cleared from the tunnel. It winds its way through the Underdark for twenty miles before eventually reaching Mantol-Derith (see chapter 6). Barracks. An archway is set into the tunnel wall near the broken gate. Passing through the archway leads to a seemingly empty barracks

CHAPTER 5 - OF MUSHROOMS AND MALICE | 39 chamber. There are twenty beds, each one covered neatly with folded sheets. A couple of large tables bear plates of uneaten food. Suits of armor and crossed swords hang from the farthest wall. Beneath the armor can be seen a jagged rift in the floor. A strange yellow dust coats the entire room. When the characters enter the barracks, two suits of animated armor and four animated swords come to life, advancing toward the characters. A voice booms from the helmet of one of the armors, “You do not belong here. Zhentarim only.” If the characters respond with the phrase, “Everything has a price.” then the armor and swords return to their place upon the wall. Otherwise, they fight until destroyed. There are small chests next to each bed. The chests contain clothing and personal effects, and one of the chests has a hidden bottom that contains a 50 gp emerald. The hidden bottom can be found with a successful DC 15 Intelligence (Inspection) check. Underneath one of the beds is a small, locked iron lockbox. Any character who makes a successful DC 10 Dexterity check with thieves’ tools can unlock the lockbox. Within are three vials of antitoxin and two potions of healing. Any character who makes a successful DC 12 Intelligence (Nature) check discerns that the yellow dust is made from some kind of unusual spores. They also note that the spores seem supernatural in origin. These are inert spores of Zuggtmoy (see the “Spore Cloud” section of chapter 3). When the gnolls triggered their sinkhole, it created a rift within the barracks that connected to a deeper section of the Underdark occupied by fungal creatures loyal to Zuggtmoy. A spore cloud drifted through the rift, infecting the soldiers stationed here. These soldiers, now enslaved to Zuggtmoy’s will, can be found in the fungal grottos below. The Fungal Grottos The rift is large enough to accommodate Large sized creatures. So long as characters are cautious they can climb into it without making any checks. It descends for roughly two hundred feet before opening up into the southern portion of area A1. As the characters descend they note the walls are covered in yellow spores and strands of mycelia. Halfway through their descent they come across two patches of violet fungi. The fungi attack any characters who get too close to them. A1. A Shrill Welcome The walls and floors of this chamber are blanketed in damp, crimson moss. The moss squelches quietly when touched, its color rippling through all the colors of the rainbow. In the center of the room, a cluster of smaller mushrooms rings a 6-foot-tall mushroom. Exits from the chamber can be seen to the west, east, and north. Any character who makes a successful DC 12 Wisdom (Perception) check notes faint, almost imperceptible footprints in the moss. A successful DC 12 Wisdom (Survival) check is sufficient to see that the footprints lead along the eastern side of the room before exiting to the north, seemingly avoiding the mushroom patch. The larger mushroom is an aging shrieker that can only detect bright light and creatures that are within 10 feet of it. If the shrieker begins to shriek, it awakens a displacer beast spore servant (see the myconid stat block for descriptions of spore servants) that is hibernating within the western passage. The awakened displacer beast charges into the room, attacking any visible characters. If the shrieker remains silent, then the displacer beast remains inactive, attacking only if damaged. A2. Vegepygmy Nursery This room has two large mushrooms that have been hollowed out. Five human corpses are propped along the eastern wall. Three of the corpses are little more than skeletons. Each of the other two corpses has what looks to be a strange, human-shaped fungal creature feasting upon their wet, decomposing flesh. These fungal creatures are vegepygmies (appendix B). If the shrieker was triggered, then the vegepygmies are watching for intruders. Otherwise, they are inattentive and easily surprised. In either case they attack if they notice the characters. During combat the two partially consumed corpses lurch upwards as guard spore servants and also attack the characters. Within one of the hollowed-out mushrooms can be found a small chest covered in a thick layer of rust-colored mold. Any character who makes a successful DC 13 Intelligence (Nature) check recognizes it as russet mold and knows that it emits toxic spores if disturbed. They also know that the mold is difficult to kill, although it shrivels up and dies if exposed to sunlight. The chest can be moved safely; however, if it is opened while it is covered in mold, each creature within 5 feet of the chest must succeed on a DC 13 saving throw or be poisoned. While poisoned this way, the creature takes 7 (2d6) poison damage at the start of each of its turns. The creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. In addition to sunlight, the mold can be killed by any amount of acid, necrotic, or radiant damage. Within the chest can be found a cluster of exotic mushrooms and a mildew mace (appendix C).

40 | CHAPTER 5 - OF MUSHROOMS AND MALICE THE FUNGAL GROTTO

CHAPTER 5 - OF MUSHROOMS AND MALICE | 41 A3. Central Cavern This immense cavern is filled with an explosion of mushrooms of all colors and sizes. Most prominent of these mushrooms are huge, distended olive green mushrooms that look as if they are about to burst. Next to one of these green mushrooms can be seen an unusual blue mushroom with bright blood-red spots. Giant mushrooms also sag from the ceiling. The bodies of eight soldiers hang from some of these mushrooms. Three winged fairy creatures, with blue skin and red spots, can be seen slicing up one of the hanging bodies with small knives. The swollen green mushrooms have reached the end of their life cycle and are ready to burst. They have an AC of 10 and if they take any damage they explode in a shower of putrid slime. Each creature within 10 feet of the mushroom must make a DC 12 Constitution saving throw. The creature takes 2d6 poison damage on a failed save, or half as much damage on a successful one. Murder sprites. The winged fairies are murder sprites. Murder sprites have the same statistics as sprites except for the following changes: • Murder sprites are chaotic evil. • Murder sprites are immune to poison damage and the poisoned condition. • The essence of a murder sprite is tied to a specific mushroom. If a murder sprite is killed, it can grow a new body from its mushroom within 1d4 x 10 minutes. Destroying its mushroom permanently kills the murder sprite. If the murder sprites notice the characters, they scream loudly, recklessly charging through the air. They attack mercilessly, screaming the entire time. The murder sprites will damage the green mushrooms if any characters are standing near them. Each of their essences is keyed to a specific red and blue spotted mushroom. All three of these mushrooms can be found in this chamber, although only one of them is plainly evident. The other two require a successful DC 14 Wisdom (Perception) check to find. Any character can spend an action to destroy one of these delicate mushrooms. Any character who makes a successful DC 15 Intelligence (Arcana or Nature) check is aware of these facts. Survivor. The hanging bodies are Zhentarim guards that the sprites have been torturing. Only one of them, a female halfling called Ezz, still lives. Ezz currently has 1 hit point remaining, but if she is restored to at least half of her maximum hit points she is willing to join the characters, swearing to “bloody prune these walking weeds.” Treasure. Characters who take the time to carefully search through the cavern’s flora find two pygmyworts, four pounds of tainted trillimac, and four pounds of tainted bluecap. The properties of these can be found in the “Fungi of the Underdark” section of chapter 3 and discerned by any player who makes a successful DC 15 Intelligence (Nature) check. Exits. There are a number of exits from this cavern. The exit to area A4 is filled with razorvine (see chapter 5 of the Dungeon Master’s Guide). A needle blight lives within the tangle of thorns and attacks any characters who disturbs it. So long as the needle blight is within the thorns, it has half cover. The exit to area A5 is a small crack hidden behind a cluster of mushrooms. It can be found with a successful DC 13 Wisdom (Perception) check. The crack is sized for Tiny creatures although a Small sized creature can squeeze through it. A4. Gulthias Tree A lone, leafless tree grows from the dried dirt of this high-ceiling chamber. The tree has no bark, exposing its bleached white core. A handful of spore bats (same statistics as a bat, except they are Plant) roost amidst its thorn-covered branches. A neutral evil dryad lives within the tree and emerges when the characters enter the room. Her form is gnarled and stunted, covered in thorns rather than leaves. She speaks with a desperate, raspy voice, asking the characters to water her tree. If the characters attempt to use actual water she interjects, “water it red. . . ” The tree is a distant offshoot of the famed Gulthias Tree (see the blight section of the Monster Manual for details). It feeds off blood rather than water and it has been quite some time since it has fed. Consequently the dryad, known

42 | CHAPTER 5 - OF MUSHROOMS AND MALICE as Gulthia, is weak and malnourished, having only 10 hit points. In her current state she cannot do much more than beg for “red water.” If the characters water the ground near her tree with freshly spilt blood she notably rejuvenates, her thorns taking on a reddish tinge. She becomes friendly toward the characters and will readily answer their questions. She knows much about the grotto. In particular she knows that it is ruled by a myconid sovereign loyal to the Demon Queen Zuggtmoy. The grotto used to connect to a larger fungal kingdom but it is now cut off from it by a recent cave-in. Gulthia also knows that the earthquake that triggered the cave-in sent spores of Zuggtmoy up into the surface world. These spores can enslave flesh and blood creatures to the will of the Demon Queen. Gulthia is willing to answer other questions regarding the grotto, although she demands 1 hit point worth of freshly spilled blood for each question she answers. She also indicates that she can cleanse the effect of Zuggtmoy’s spores but demands 2 hit points worth of freshly spilled blood each time that she does so. A5. Hidden Treasure! This small room is where the murder sprites from area A3 hide their treasures. Their idea of treasure, however, is mutilated corpses. The chamber is filled with thousands upon thousands of bones from creatures ranging from rodents to carrion crawlers. If the characters search through the bones, they find three 100 gp tourmaline gemstones, a fungal veil (appendix C), and a cookbook of Underdark delicacies worth 200 gp to a surface world collector. Characters who take the time to read through the cookbook find a recipe that describes how to properly cook tainted bluecap. A6. Lichen Garden A pool of shallow water takes up the eastern end of the room. On the western end of the room is what looks to be a garden of multi-colored lichen. Two Zhentarim soldiers shuffle back and forth from the pool and the garden. They fill their helmets with water from the pool and use it to water the garden. Strands of white mycelium can be seen twining about their bodies and burrowing into their flesh. Their skin is covered with what looks to be rashes of acne that, if inspected further, can be seen to be thousands of tiny sprouting mushrooms. The Zhentarim guards are under the effect of Zuggtmoy’s spores. One of them has a glazed look and pointedly ignores the characters. The other, however, looks at the characters with tears in his eyes. In a rasping voice, he begs, “Please. Kill. Me.” With each word he coughs out a cloud of yellow spores. Neither guard puts up a fight if slain. Alternatively, they can be saved by Gulthia or any magic or effect that cures disease. A7. Throne Room of the Mushroom King A large humanoid-shaped mushroom sits upon a gargantuan throne of interwoven fungi. The creature is tended by three guards that have been corrupted by Zuggtmoy’s spores. The guards are meticulously scrubbing dirt and debris from the mushroom creature’s fleshy torso. Two vegepygmies stand guard on either side of the throne. The mushroom creature is a chaotic evil myconid sovereign named Gargan who rules over this grotto. Instead of Pacifying Spores, Gargan has the following action: Infestation Spores (Recharge 5−6). Gargan ejects spores at one creature it can see within 5 feet of it. The target must succeed on a DC 12 Constitution saving throw or become infected with a disease known as the spores of Zuggtmoy. On a successful saving throw, the creature can’t be infected by these spores for 1 minute. While under the effect of these spores, the creature is incapacitated, spending its turn coughing and vomiting. The creature can repeat the

CHAPTER 5 - OF MUSHROOMS AND MALICE | 43 saving throw at the end of each of its turns, ending the infection on a success. On a failure, the infected creature’s body is slowly taken over by fungal growth, and after three such failed saves the creature becomes enslaved to the will of Zuggtmoy. This effect can be removed by any effect that cures diseases, such as the lesser restoration spell. It is left to the DM’s discretion as to how the infected creature might best serve the will of Zuggtmoy. Gargan lives in symbiotic balance with the grotto and is thus alerted whenever the characters reach the chamber. The myconid sovereign attacks immediately, aided by its enslaved guards and vegepygmy servants. The Zhentarim guards beg the characters for mercy, all the while trying to cut them down mercilessly. The fungal sovereign and its servants fight to the death. The tunnel to the northwest is cut short by a wall of fallen rubble, the result of a recent cave-in. Two enslaved guards claw at the rubble as if trying to dig through it. The flesh has scraped away from their hands and their finger bones are broken; however, they still continue to dig while intoning repeatedly, “We must reach Zuggtmycos. We must return to the Great Mother.” These guards are oblivious to the characters. The tunnel once led deeper into the Underdark, allowing passage to the fungal colony known as Zuggtmycos; however, now it is blocked with rubble due to the recent gnoll-induced earthquake. Conclusion The Red Wyvern pays the characters 200 gp if the characters successfully kill Gargan. She also pays an additional 10 gp for each guard that still lives. Any character affiliated with the Zhentarim gains seven renown. Allow the characters to advance to 3rd level. If the characters left any infected guards alive within the grotto, then the Red Wyvern dispatches a druid (there are few clerics within the Doomed Forgotten Realms, as most residents believe that the gods have been killed by Vecna) to cure them. She also instructs the druids to investigate and analyze the spores that enslaved the guards. Simeon seems quite worried about the spores, informing the characters that the Zhentarim have never come across anything like them before. The dragonborn mentions that there is a deep gnome druid named Wythlon residing within MantolDerith. Wythlon is rumored to be an expert in Underdark flora and might know of a way to effectively neutralize the spores. Simeon asks the characters to escort a Zhentarim trade caravan to Mantol-Derith to speak with Wythlon. If they do so, the dragonborn is willing to pay them 100 gp before they go and another 100 gp when they report back. For details on Mantol-Derith see chapter 6.

44 | CHAPTER 6 - MANTOL-DERITH Mantol-Derith is important as it is home to the deep gnome Wythlon, who the characters have been sent to find (see area B10). It also provides a base of operations for the adventures outlined in chapters 7 through 9. More generally, however, Mantol-Derith can serve as a friendly settlement for any Underdark-based adventure within the Doomed Forgotten Realms. Regional Effects. Despite his imprisonment, Graz’zt’s abyssal presence still taints the souls of those that visit Mantol-Derith. Hedonistic urges become increasingly irresistible. Small desires turn into burning obsessions. The citizens of the subterranean town carry a bit of extra weight due to their unchecked gluttony, and their bloodshot eyes reflect a lack of sleep, a hangover, or often both. Mechanically, this corruption manifests as the characters making all Wisdom saving throws with disadvantage while in Mantol-Derith. In terms of role-playing, consider encouraging the players to magnify any of their relevant ideals, bonds, or flaws. The influence of Fraz-Urb’luu is more subtle but just as powerful. Deception checks are made with advantage, and checks to discern illusions are made with disadvantage. Spells such as true sight and zone of truth do not function while in Mantol-Derith, although this is not overtly evident to those casting or using these spells. Mantol-Derith Exterior Locations of note outside the city include: B1. Main Thoroughfare The main tunnel that leads from the surface world into Mantol-Derith is broad enough to comfortably accommodate two wagons side-byside. Stalagmites, stalactites, and all other rock formations have been cleared from the tunnel. Rivulets of water trickle ceaselessly from above, creating an obstacle course of flooded potholes and slippery stone. Two hundred feet from the entrance to MantolDerith, hundreds of small niches have been carved into the stone walls. Each niche holds the head of a drow. Most of these heads have rotted away to the point of being little more than skulls, although a few appear to be freshly severed. One hundred feet from the city, there is a threshold of arcane runes glowing a harsh, bright red. These runes have been placed here by Graz’zt and can be found protecting any access point to the city. Any Fiends that approach the threshold N ot all demons conquer through violence. Some do so through seduction and guile. Such was the case when, during the Incursion, Graz’zt took over the leadership of Mantol-Derith. Shortly thereafter Fraz-Urb’luu tricked the Dark Prince, trapping him within a gemstone prison. It is now Fraz-Urb’luu, the Demon Prince of Illusion, who guides the politics of Mantol-Derith, although he does so under the guise of Graz’zt. For more details on these events, see chapter 1. Introduction Before the Incursion, Mantol-Derith served as a small trading outpost frequented by drow, duergar, svirfneblin, and Zhentarim traders. Now, years later, it has greatly expanded. Fraz-Urb’luu has turned the previously hidden community into a bustling underground city where the numerous refugees of the Underdark can find sanctuary. The demon lord rules this ever-growing city with a silken glove, subtly influencing and manipulating the citizenry into doing his bidding. The trading outpost was originally built within a large cavern carved out by thousands of years’ worth of trickling water. Over the last few years, it has been enlarged to accommodate the influx of refugees left homeless by the Incursion. All refugees are welcome except for the drow, who are openly vilified and blamed for summoning the demons into the Underdark, and a bounty is paid to those willing to hunt down the dark elves and kill them (see area B1). If you have a character who wishes to play a drow, collaborate with them to find a way for them to enter Mantol-Derith, perhaps by obtaining a writ of passage from the Zhentarim. Such characters might be met with animosity rather than armed hostility. Mantol-Derith is situated along the shores of the Darklake. It is roughly six days’ travel from Blingdenstone and the ruins of Menzoberranzan. There are dozens of caves and crevices from the surface world that wind their way into an enlarged tunnel that leads into the heart of the city. The existence of these subterranean pathways used to be a secret exclusive to the Zhentarim. However, as the city has grown, so too has its notoriety, and the tunnels are now used freely by any number factions and travelers. Depending on which access point is used, the journey from the surface to Mantol-Derith can range anywhere from one to six days. Chapter 6 - Mantol-Derith

CHAPTER 6 - MANTOL-DERITH | 45 feel an ominous sense of dread. They must make a successful DC 18 Wisdom saving throw to move past the threshold. If they do so, they take (55) 10d10 force damage. If a Fiend fails their saving throw, they cannot attempt a new one until dawn of the next day. Adamantine gates, salvaged from the wreckage of Menzoberranzan, now block the entrance to Mantol-Derith. The gates are barred from the inside and are guarded by three guards, a veteran, and a mage loyal to the Zhentarim. The guards suspiciously question any visitors, first inquiring if they are carrying any bounty. If the characters ask about the bounty, they are informed that by the Prince’s Decree they are authorized to pay 10 gp for the head of a drow elf, up to a total of 200 gp. Whenever the guards receive a fresh bounty, they place it in the niches that the characters passed earlier. If the characters do not pose any obvious danger, they will be admitted into the city for the cost of one gp each. Role-Playing. The lack of sun and claustrophobic confines of Mantol-Derith wears upon the nerves of the surface-dwelling Zhentarim. Because of this they are irritable and tense. There is also a 30 percent chance that any given guard is suffering from a randomly selected long-term madness (see the “Madness” section in chapter 8 of the Dungeon Master’s Guide). If the characters are accompanying a merchant caravan, then the merchant will handle speaking with the guards and pay for the characters’ admission. The merchant is knowledgeable enough to mind their words, so as not to infuriate the easily angered Zhentarim. At your discretion the merchant might be carrying a sack of severed drow heads that they turn in as bounty. Mantol-Derith

46 | CHAPTER 6 - MANTOL-DERITH B2. City Entrance Another contingent of three guards, a veteran, and a mage stand guard within the city. When signaled to do so by their colleagues in area B1, they unbar the gate to allow entrance to the city. These guards have a laxer demeanor than their peers, and it is much easier to leave the city than it is to enter it. The road leading into the city is paved with crushed stone. Flanking it are four large, mansized chunks of jagged quartz. Figures can be seen imprisoned within the stone, seemingly burning within a torrent of hellish flames. The figures writhe and scream noiselessly as if in great torment. The figures include a male duergar, a female deep gnome, a female drow, and a gargoyle. A plaque is set into the base of the duergar’s stone, and reads: By edict of Graz’zt, the Great Savior and Uniter of the Underdark, these treacherous curs have been sentenced to an eternity of unending torment for their crimes of theft and violence within the protected limits of Mantol-Derith. Let this be a warning to any who might consider walking the same path. Although the quartz stones are real, the burning images within them are illusory. This can be discerned by any character who examines them closely and makes a successful DC 20 Intelligence (Investigation) check. Mantol-Derith Interior The city is located within an enormous cavern with a 50-foot-high ceiling supported by naturally formed stone columns. The glow of enchanted stone lamp posts reflects off crystals embedded in the roads that drunkenly wind their way through a chaotic collection of mismatched buildings. Water is everywhere, dripping from the ceiling to form puddles, pools, and streams. Because of the moisture there is a proliferation of mold and fungi, growing to varying degrees within every visible crack and crevice. Deep gnomes, duergar, and humans can be seen walking through the city, many of them wearing strange stone masks. If the characters inquire about Wythlon they are directed to area B10. Spore Masks To help deal with the spores infesting large swaths of the Underdark, deep gnome artificers created protective stone masks. These decorative masks can be carved to look like any number of creatures, although owlbears are most popular. Thin slices of fungi are inserted within the mask to purify any inhaled air. These masks typically sell for 10 gp. Anyone wearing such a mask has advantage on saving throws made against spores but disadvantage on Perception checks. Possible encounters while wandering the city include: Glabbagool. The characters notice a cube of quivering gelatinous slime slurping its way along one of the roads. Floating within it is what must be close to a thousand shiny, sparkling clean copper coins. Nearby townsfolk do not seem alarmed, sidestepping the slime before continuing to move about their business. Some of them stop to flick a copper piece into its wavering mass. The cube of sentient slime, Glabbagool, is one of Mantol-Derith’s more unusual citizens. Glabbagool has the same statistics as a gelatinous cube, except that it has an Intelligence

CHAPTER 6 - MANTOL-DERITH | 47 of 10 (+0) and telepathy out to a range of 60 feet. Citizens occasionally throw coins into Glabbagool, believing doing so will bring them good luck. This tickles a bit, but otherwise the gelatinous cube does not mind. Glabagool is more than happy to telepathically speak with the characters. Should the Ooze find out that they are from the surface, it reacts with awe, asking questions such as “What does the sun smell like?” and “What does it feel like to touch a cloud?” The first character to toss a gold or platinum coin into Glabbagool gains inspiration. Regardless of denomination, if a character tosses a coin into Glabbagool, a nearby duergar shouts, “If ye be making a wish, yer coin be best spent at the wishing well down yonder.” If the duergar is questioned they refer the characters to area B13. Sir Dalian Trueworthy. The characters come across a young handsome knight with long, flowing blond hair regaling a crowd of spectators with an epic tale. The bardic knight is Sir Dalian Trueworthy. Despite his human ancestry Sir Dalian has delicate elven features. He wears devil bone armor and his shield is emblazoned with the symbol of a silver dragon’s profile, signifying Bahamut, the dragon god of justice. Sir Dalian is a member of the Hell Riders, an order of paladins who were banished to Avernus along with Elturel. For years the Hell Riders fought against hordes of devils, protecting not just Elurel, but Baldur’s Gate as well. The valiant paladins, led by the High Rider Ulder Ravengard, managed to lead the citizens of both settlements through the apocalyptic wastelands of Hell to eventually emerge within the Underdark, where they have since created a stronghold that they have christened New Elturel (see the “Fardrimm” section of chapter 2). The knight greatly enjoys boasting of his adventures in Hell, filling such tales with epically preposterous embellishments. Sir Dalian is one of hundreds of knights who has been dispatched throughout the Underdark and the surface world with a magical scroll known as the Divine Pact. These knights are seeking to rally the Realms against the devils and demons that, if left unchecked, will surely tear the world asunder. As part of this they are asking people to pledge their loyalty to the cause by signing the Divine Pact. Any character who agrees to sign the radiant scroll feels an infusion of divine vigor and gains 2d4 temporary hit points that last until they are depleted. Veldyskar. The characters encounter a giant lizard lying amidst a bed of lichen singing to itself. The creature is a special basilisk named Veldyskar that has an Intelligence of 10 (+0) and speaks Common, Dwarvish, Giant, and Undercommon. Veldyskar once served as a guardian for the library Gravenhollow. The basilisk is one of the few creatures aware of Ustova’s corruption (see “Gravenhollow” in chapter 2) and because of this was driven from Gravenhollow by the corrupted seer. After months of wandering the Underdark Veldyskar eventually settled within Mantol-Derith. Veldyskar is a shy creature that easily loses its temper. The basilisk purposely keeps his eyes downcast while talking, so as not to accidentally petrify anyone. He misses being in the library and enjoys discussing academic topics. He learned much from his time in Gravenhollow, including the ability to cast greater restoration once per day, which can be used to restore anyone who becomes accidentally petrified. Because of his extensive knowledge and special ability, Veldyskar might serve as a source of lore and healing for characters who take the time to befriend him. He might also serve as an adventure hook for campaigns seeking to utilize Gravenhollow. B3. Lost and Found This precarious structure is made from dried, cracked mud. Within is what appears to be an overwhelming array of haphazardly organized junk arranged upon rows of buckling shelves. The building is tended by Anyra Boulderbarrel, a matronly halfling known for her kind demeanor and long, fiery red locks. Anyra is assisted by a team of seven colorful sprites, one for each color of the rainbow. With the upheaval caused by the Incursion, many of the Underdark’s denizens were forced from their homes, often leaving behind prized possessions. Anyra was one such denizen who, while fleeing her burrow, lost some cherished paintings that were made for her by her departed mother. Knowing firsthand the pain of such loss, she opened this pawn shop to help both herself and others. Role-playing. The aging, kind-hearted halfling never married or had children, but never let that stop her from having a rich social life. As far as Anyra knows she is the only survivor from her burrow and misses her friends and family dearly. Despite that, or perhaps because of that, Anyra is the consummate host and almost always has several friends visiting her shop, sharing stories. The sprites are shy but curious, hiding amidst copper spittoons and burlap coats while listening to Anyra talk away the day with her many visitors. Quests. When the characters enter the shop Anyra is busy scrutinizing a heavily tarnished brass plaque. If asked about the plaque, Anyra indicates that she thinks it was once a duergar treasure map, although it is now too heavily tarnished to read. If asked to do so she is willing

48 | CHAPTER 6 - MANTOL-DERITH to sell it to the characters for 10 gp. The plaque is covered in heavy corrosion that must be cleansed with care to preserve the map underneath. If the plaque takes exactly 10 points of acid damage (something which happens if it is placed within the gelatinous cube mentioned in area B2) the corrosion is perfectly cleaned without damaging the map. Other cleaning methods might also be successful, at the DM’s discretion. The map leads to a hidden chest, two days’ travel from MantolDerith, that contains three rubies worth 100 gp and a randomly determined magic item from Magic Item Table B in the Dungeon Master’s Guide. B4. Stoneschlager Brewhouse With most residents of Mantol-Derith imbibing alcohol on a near daily basis, issues began to arise with their ever-increasing tolerance as well as a dwindling supply. An entrepreneurial svirfneblin by the name of Brogla Cobbleheart quickly solved this problem by bringing back the age-old dwarven tradition of stone fermentation, founding the Stoneschlager Brewhouse. The Stoneschlager Brewhouse is a large building made from blocks of serpentine stone quarried from a distant yuan-ti settlement. It is ringed by a bed of soft moss upon which inebriated patrons can sleep off their stupor before staggering home. The front half of the brewery is a bustling bar that is often standing room only, whereas the back half is filled with the bizarre contraptions used to ferment and brew the bar’s signature stoneschlager. The interior should reek of vomit; however, Brogla pays a rotating crew of apprentice wizards to routinely cast prestidigitation and mask the stench. The tavern’s most popular drinks are granite guzzlers and shale shots, either of which can be purchased for 1 sp. Wealthy hedonists can literally consume their own money by personally paying Bragla 50 gp to craft a pint of her infamous goldschlager. A character who consumes any of these potables must make a successful DC 10 Constitution saving throw or become afflicted with the poisoned condition until they complete a long rest. The character must also, due to Graz’zt’s regional influence, make a successful DC 10 Wisdom saving throw or begin immediately craving another drink. For each additional drink consumed, the saving throw DC increases by one. Any poisoned character who fails their Constitution saving throw suffers one level of exhaustion. Role-playing. Most patrons here are overly drunk and act accordingly. The wait staff are underpaid and overworked, hence not interested in idle conversation. Conversation is made more difficult by not just the drunken din but also the sound of grinding stone that can be heard from the backroom, where Bragla spends most of her time. The deep gnome is a workaholic who hardly sleeps because she is so consumed with her craft. She is generally reclusive, although characters can earn her attention by purchasing a pint of goldschlager. In this case she enthusiastically brings the characters into the backroom and shows them how the brewing process works. Quests. If the characters can earn her attention, Brogla has many fanciful ideas for future products including drinks made from fermented wormrock or bloodstone. Brogla will happily pay the characters 100 gp for a pound of wormrock and one hundred and fifty percent of the value of any bloodstones brought to her. She advises the characters that they can find wormrock within the Wormwrithings and that there is an abandoned bloodstone mine near the mind flayer city Cyrog.

CHAPTER 6 - MANTOL-DERITH | 49 B5. Den of Delights The den of delights is carved into the soft inner belly of a towering, spotted mushroom. It is run by the bronze dragonborn Botak’tal. The draconic proprietor has devised a process of bottling and selling their sleep breath for 5 gp a vial. The bottled fumes are functionally equivalent to essence of ether from the Dungeon Master’s Guide except they have a save DC of 10 and lose their potency within 24 hours. Patrons typically purchase the ether with the intent of using it upon themselves. For gaming groups comfortable with such a thing, Botak’tal can also provide access to a variety of escorts and companions. Role-playing. Botak’tal speaks with a fake hiss, believing that this emphasizes their draconic heritage and intimidates those they are speaking with. The dragonborn is well informed, knowing not only most of the town’s residents but their secrets as well. Botak’tal is greedy to a fault, refusing to share even the smallest piece of information for free and often charging more than their mark can afford to pay. Quests. If the characters seem capable and willing to work for money, Botak’tal asks them to “find” a Zhentarim writ of passage (see area B15) for them. If the characters succeed at this, the dragonborn asks them to return in two hours so that they can secure their payment. If they return at the appointed time, Botak’tal pays them, as promised, but also arranges to have one of their clients in the room, seemingly passed out. The next day the client attempts to blackmail the characters on behalf of Botak’tal, threatening to turn them into the Zhentarim if they do not give her 400 gp. B6. Keldrin's Library A small crack in the floor of Mantol-Derith leads through a cramped, twisting tunnel that eventually opens into a swelteringly hot cavern. This cavern is the shop and home of Keldrin, an azer archmage. Keldrin’s shop is filled with the usual bric-a-brac associated with a wizard’s laboratory. The most remarkable feature is a large boulder that sits in the center of the floor. For those looking closely, a sigil can be seen etched into the boulder’s base. Role-playing. The cantankerous old mage nominally makes his living as a scholar and sage, although he is so mean and abusive to those seeking his help that he can go months at a time without any clients. He is well versed in a variety of subjects and generally shares his knowledge for free, “So long as you annoying pests promise to leave afterwards and never return.” This cruel façade, however, masks a deep loneliness and yearning for companionship that can be discerned by any character who makes a successful DC 18 Wisdom (Insight) check. Quests. Keldrin is reluctant to talk about the boulder but can be persuaded to do so with a successful DC 13 Charisma (Persuasion) check. If persuaded to talk, he informs the characters that the boulder is an earth node and summarizes the information contained in the earth node sidebar. Keldrin admits to knowing how to travel through earth nodes but refuses to share this knowledge with the characters. Should they offer to trade for it, Keldrin scoffs, “Fah! What could you possibly offer that would be of interest to an old man like me. . . What I want you’ll never be able to….” Any character who makes a successful DC 10 Wisdom (Insight) check discerns that he is holding back, though Keldrin refuses to discuss what it is he truly wants. Keldrin pines for the affections of Anyra (see area B3). In his imagination there is no way that she could return such affections, but in truth, she is impressed but intimidated by the azer and open to pursuing a relationship with him. Should the characters facilitate this, Keldrin gladly teaches the ancient ritual needed to use earth nodes (see sidebar) to any character proficient in Arcana. Such instruction takes one day to complete. Earth Node Earth nodes are nexuses of elemental energy scattered throughout the vastness of the Underdark. Each node has a specific sigil associated with it. For those who know the appropriate sigils, ancient rituals can be used to travel from one node to another. These ancient rituals, however, are forgotten by all but a handful of sages. Keldrin is one of the few remaining sages with knowledge of earth nodes and their associated ritual. The ritual takes one hour to complete and requires a gemstone worth at least 100 gp, which is consumed upon use. Once the ritual is completed, the caster can transport themselves and up to eight willing creatures standing within 60 feet to any other known earth node. B7. Grugg's Gastro Buffet This festhall is made from slabs of petrified wood decorated with colorful swaths of luminescent paint. The establishment is run by Grugg, a gregarious ogre who is never without his floppy chef’s hat and massive wooden ladle. One half of the festhall is taken up with large troughs filled with a sweet-smelling gruel. The ingredients of the gruel vary from day to day but are typically some combination of fish, vermin, and ground up fungi. A patron can purchase a ladle and eat their fill for 5 sp.

50 | CHAPTER 6 - MANTOL-DERITH The other half of the festhall is taken up by a stage and dance floor where drunken musicians play off-beat music to dozens of sweating revelers dancing themselves to exhaustion. Any character who takes the time to listen to the music must make a successful DC 10 Wisdom saving throw or get swept up by the bacchanalian beat for the next 10 minutes, after which they can attempt another saving throw. For every 10 minutes spent dancing the character loses a hit die. If the character does not have a hit die to lose, then they suffer one level of exhaustion. Role-playing. Grugg is a pompous chef who loves bragging about how he apprenticed for a year in Skullport under the legendary halfling gourmand, Smallfry. Grugg tries hard to sound smarter than he is, often misusing and mispronouncing large words. The ogre is an excellent chef but also a people pleaser, dwelling for days over the mildest of criticisms. Quests. Grugg is always on the lookout for exotic ingredients in hopes of creating a culinary masterpiece that might rival those of his mentor, Smallfry. Currently Grugg is looking for ectoplasmic residue, something that can be obtained from a ghost that is either defeated or put to rest. The ogre will pay 200 gp to the first person to bring him this residue, which he plans to use to make a “frighteningly good” feast. B8. Amarith's Zoo A tall fence of hardened briars rings a collection of stalagmites. Cages have been carved into smaller stalagmites that hold a variety of creatures such as a rare black-hued stirge with four sets of wings, a cyclops that has been permanently reduced to one foot tall, and a blink dog that has been polymorphed into a tressym. The zoo is run by Amarith, a shield dwarf veteran. Role-playing. Amarith is chatty and excited for any opportunity to show off her zoo. However, she begrudgingly refuses to admit any characters who are noticeably intoxicated as it has become a running gag for drunkards to enter the zoo and try to release the animals. The shield dwarf, unfortunately, has little business sense. She will attempt to charge the characters 5 gp each for admittance but can be easily haggled down, even going so far as to admitting them for free.