Sarkt is an illithid sorcerer. It was cast out of its community for its heretical studies (Sarkt was in fact, lucky to escape alive). It didn't take the cunning creature long to pick up a few thralls and find a new place to live, safe from the murderous intentions of its companions. Sarkt dwells in the subterranean ruins of an ancient shrine to Blibdoolpoolp, the crustacean-headed deity of the kuo-toas. This shrine lies on the fringe of a region controlled by kuo-toas, but since Sarkt's arrival, the fishmen avoid the area. A few unfortunate kuo-toas now serve Sarkt as thralls and maintain the illusion that the shrine serves Blibdoolpoolp. Pgs. 82-88

A powerful new narcotic is making its way through the Spine of the World. Behind it is a secret that could change everything! Explore a lost city and discover the secrets hidden by the gods themselves. (TW: some drug use and the possibility for players to use drugs)

To travel further into the Underdark the party must cross a bridge spanning a deep chasm. But to cross, they must pay the toll, or risk another route.

The Shattered Circle is an AD&D® adventure for four to six player characters of 1st to 3rd level. For many ages, the standing stones known as the Circle of Cahervaniel have stood on a grassy hilltop, unremarkable and unmenacing, but something has changed. A powerful artifact deep within the earth has been uncovered, and its evil power has corrupted the recent inhabitants of a dungeon complex. The chitine live within, a cross between humans and spiders created by the drow, but trying to live a quiet existence. The evil Foundingstone has corrupted some of the chitine, and split their society in two, bringing them to conflict. Adventurers who navigate the chitine factions and dangerous dungeon will need to end the threat of the Foundingstone and the solve the mystery of the strange dark unicorn Mizar that has appeared recently around the stones. Interestingly, one of the unique magic items in this adventure, Icerazor - is said to have grown from a shard of Frostrazor, a sword that appears in a famous later adventure - Return to White Plume Mountain. There is a brief mention of Suloise, so it can be considered a Greyhawk adventure, but clearly states it can be placed anywhere.

The Underdark is a subterranean wonderland, a vast and twisted labyrinth where fear reigns. It is the home of horrific monsters that have never seen the light of day. It is here that the dark elf Gromph Baenre, Archmage of Menzoberranzan, casts a foul spell meant to ignite a magical energy that suffuses the Underdark and tears open portals to the demonic Abyss. What steps through surprises even him, and from that moment on, the insanity that pervades the Underdark escalates and threatens to shake the Forgotten Realms to its foundations. Stop the madness before it consumes you! Note for DMs: This adventure is not for the faint of hearted, to run or to play. The module starts with 10 NPCs traveling with the party through the grueling Underdark. This number can grow. The encounters within the book are often incredibly deadly for the characters that would be going through it. This is because the module expects them to run or talk their way through the events, or, in some cases, the module expects them to lose. If your players aren't the kind of party to run, talk, or surrender, do not get this adventure. The module almost requires that you use milestone leveling because the experience provided does not commonly get players to the levels they should be once they get to certain milestones in the story (7th when they leave the underdark, 15th when they face the demon lords.) Good luck and happy questing.

The most deadly dungeon ever devised! High-level characters brave the unexplored corridors of Deepearth to confront perhaps the most feared adversary in the AD&D game. The second chapter of the Bloodstone Pass saga follows the conclusion of the desperate war against the bandit army. A cold and bitter winter drives the villagers to the edge of starvation, and numerous horrors strike the town of Bloodstone Pass. Join the adventure as the heroes explore the depths of the ancient bloostone mines, now inhabited by fearsome demons. There they hope to uncover the fantastic treasures rumored to exist in the unknown darkness. But deep within the mines, all is not what it seems.... This module uses the new rules from the Dungeoneer's Survival Guide and Wilderness Survival Guide. The adventure also includes optional BATTLESYSTEM scenarios fought entirely underground. These supplementary products are not required to play the adventure, however. TSR 9168

A band of evil fey, led by a corrupt bralani, has raided an eladrin city and kidnapped several respected elders. The fomorian king claims the rogues don’t act on his behalf, but the eladrin city threatens the fomorians all the same. To prevent war, the PCs travel through the Underdark of the Feywild—a wondrous place filled with the beautiful and the horrifying—in search of the evil fey and their captives. Pgs. 96-101

Having put down a rising of giants, it was discovered that the motivating force behind their depredations was that of long-forgotten evil - the Dark Elves. Determined to seek out these creatures, a body of doughty adventurers mounted an expedition to learn the strength of the Drow and bring retribution to them (DUNGEON MODULE D1, DESCENT INTO THE DEPTHS OF THE EARTH). This module contains background information, a large-scale referee's map with a matching partial map for players, referee's notes, special exploration and encounter pieces, a large map detailing a temple complex area, encounter and map matrix keys, and an additional section pertaining to a pair of unique new creatures for use with this module and the game as a whole. A complete setting for play of ADVANCED DUNGEONS & DRAGONS is contained herein. This module can be played alone, as the second part of a series of three modules (with DESCENT INTO THE DEPTHS OF THE EARTH, D1, and VAULT OF THE DROW, D3), or as the fourth part of a continuing scenario (DUNGEON MODULES G1, G2, G3, D1, D2, D3, and Q1, QUEEN OF THE DEMONWEB PITS). TSR 9020, From 1978

The Ghost Tribe of Orcs were driven from their home under Wyvern Tor by some terrible evil. They marched to Phandalin and attacked only to be defeated. Then, the heroes journeyed to the orc’s former settlement beneath Wyvern Tor and found the source of the orc’s sardonyx and the umber hulk that drove the orcs out. Now, the party has to go deeper to deal with the terror from the Underdark that caused all of this excitement.

Of all the inhospitable domains in the RAVENLOFT@ campaign world, Bluetspur is the cruelest and most gruesome. Nothing grows in the endless night, and lightning periodically falls like rain. The only place to escape those storms is inside the mind flayers' complex under Mt. Makab, but that is the last place where any sane person would want to go. The High Master Illithid has been hatching black plots by hatching vampiric mind flayers in his laboratories! His prodigies are horribly insane, but if he can complete his plans, he will achieve a new level of dark immortality. A pair of heroes has stolen the key to his success, but they have paid a heavy price for their bravery and are in desperate need of aid unlooked for. Meanwhile, the Lord of the Realm watches over the proceedings and plays havoc with the wits of both sides, sapping strength and will with all-powerful thoughts of darkness. A party of adventurers will need all of their skills to escape this black domain without the loss of life, power, or sanity! Enter now the perpetual twilight realm of Bluetspur, home to mind flayers, a land of relentless nightmares. There's no rest for the wicked or the good in this domain. Once caught within the borders of this desolate land, the characters must complete their mission without delay or lose their minds and become slaves of the Lord of Bluetspur. TSR 9264, from 1992

Ruins of the Grendleroot is a book of ten easy-to-prep and easy-to-run adventures for the fifth edition of the world's most popular fantasy roleplaying game. Designed for characters of 1st to 5th level, these adventures take place in the caverns, chambers, tunnels, and ruins of Blackclaw Mountain, within which lurks a strange otherworldly sentience known as the Grendleroot. Ruins of the Grendleroot focuses on the sense of mystery and wonder that comes from exploring ancient ruins and lost chambers. The central hub of these adventures, Deepdelver's Enclave, is a frontier outpost overlooking the ruined city of Shadowreach, set deep within the mountain. In Deepdelver's Enclave, adventurers and explorers recount tales of their explorations, trade treasure and artifacts, and enjoy their shared love of uncovering the mysteries of the mountain.

After a drow girl goes missing, characters must delve into the depths of the Underdark to bring her back. As they journey through the dark, characters discover not all monsters are monstrous and webs are capable of restraining all manner of creatures; in fact, they can capture magic itself.

Tonight, a ceremony of light is taking place on the surface. Meanwhile, a world away in the city of spiders, a drow matron solidifies a pact with soul-consuming entities who require great sacrifices in trade for unimaginable power. Drow eyes turn to the surface. This book contains a mega-adventure and setting, taking characters across the surface and into the depths of the world. Adventurers will meet unique denizens, battle horrors of the Underworld, explore epic locations, and fight to stop the rise of the drow.

An unexpected envoy arrives in Sporedome and offers to give aid against the fire giants of Maerimydra, if you are willing to help his people with a small problem. A two-hour adventure for 5th through 10th level characters. Optimized for five 8th level characters.

On a nameless, featureless demi-plane the Tarrasque rages across an all-encompassing nothingness. Last seen on Faerun a century ago during the cataclysm of Odobaz, the battle mage order of the Eldritch Storm sacrificed itself to banish the mighty titan to its demi-plane prison. Now a foul power emerges in the High Ice and nightmare visions of the Tarrasque trampling cities wrack the minds of the living—can your adventurers defeat the Horror Under the Mountain?

"The Aboleth's Grotto" is a nihileth lair suitable for four 10th-level characters. The adventure can be completed in one session. The small town of Springwell harbors a secret that almost nobody knows about, and those who do conveniently ignore: it sights right over an unoccupied settlement of the deep caverns of the underworld.

Dark Water Trap is a mini-adventure that has a single encounter that involves Duergar using darkness and anti-darkvision to get the player to fall into a Pit trap full of water, so that the party will drown. The encounter either works as a standalone (Ie. the Duergar have been causing trouble), or as a part of a larger adventure or dungeon, Duegar or otherwise. Pgs. 26-27

From the backcover: "Once a generation, they say, a strange comet appears in the sky overhead and the gates of Firestorm peak swing open, (twenty-seven years ago, your father led his band of adventurers into the mysterious mountain, never to return. Now the Dragon's Tear once more flickers in the sky, and the glass gates on the mountainside beckon. Will you pass through to discover the secrets that await beyond the portal none has ever dared and returned? The Gates of Firestorm Peak is the first adventure designed especially for use with the new rules presented in the three PLAYER'S OPTION books: Combat & Tactics, Skills & Powers, and Spells & Magic. While it can also be played using just the AD&D® game core rules (the Player's Handbook and the DUNGEON MASTER® Guide), this adventure offers a perfect opportunity to experience all the potential of the new optional rules. One of the highlights of this package is the first PLAYER'S OPTION player character record sheet. To meet the challenges of Firestorm Peak and escape with their lives, heroic adventurers must battle dark dwarves in their underground city, explore the abandoned caverns of the Elder Elves, and deal with weird alien entities from Beyond. Their goal is to stop the Master of the Twisted Caverns and his dark minions from completing his sinister plot before it's too late . . . if they can. Included in this product are a 96-page adventure book detailing the dungeon that lies beneath Firestorm Peak, 4 full-color poster maps detailing all the important locations in the complex, and a sheet of 56 counters for use with the tactical maps in major combats."

a baron recruits the party to find a set of magical swords as well as explore a mine shaft that connects to the under dark

Eons ago, the demon lord Shomarrah defamed Lolth the Spider Queen, condemning herself into the cursed life of a massive purple worm. Now Shomarrah's desecrated body serves as a drow fortress, guarded by a mad sorcerer and his team of driders. What deeper evils lie within? "The Fasting Worm at the Spider Feast" is a Dungeons and Dragons 5th Editionmodule for a party of 3-5 players at level 8. This one-shot module is perfect for introducing your party to the Underdark and drow society, featuring a dungeon dive through a demon lord's snake-like carcass. Clerics in the party, upon completing the adventure, will be able to obtain access to the Feast domain. Details are provided at the end of the module