As a member of a bold party of adventurers, you and your associates have trekked far into what seems to be a whole underworld of subterranean tunnels -- arteries connecting endless caves and caverns which honeycomb the foundations of the lands beneath the sun. Your expedition has dogged the heels of the Dark Elves who caused great woe and then fled underground. This module can be played alone, as the conclusion to module D1 & D2: "Descent into the Depths of the Earth," or as the third module in a series that forms a special extended adventure (G1-G3: "Against the Giants"; D1-D2: "Descent into the Depths"; and Q1: "Queen of the Demonweb Pits"). TSR 9021

The waters of a sunless sea meet a pebble-strewn shore, beyond which opens a wide Underdark vista shimmering with pale cave-light. Titanic columns as big as castles march miles into the misted distance. The wide, steeply sloping base of the nearest colossal column is carved with streets, walls, and elaborate structures, many with gaping, empty windows. A few glimmer with faint illumination. Are you brave enough to explore the spire-city and face the terrors that lurk within? Part 2 of the Barrow of the Forgotten King series. Followed by Fortress of the Yuan-ti.

In the city of Waterdeep rests a tavern called the Yawning Portal, named after the gaping pit in its common room. At the bottom of this crumbling shaft is a labyrinthine dungeon shunned by all but the most daring adventurers. Known as Undermountain, this dungeon is the domain of the mad wizard Halaster Blackcloak. Long has the Mad Mage dwelt in these forlorn depths, seeding his lair with monsters, traps, and mysteries—to what end is a constant source of speculation and concern. This adventure picks up where Waterdeep: Dragon Heist leaves off, taking characters of 5th level or higher all the way to 20th level should they explore the entirety of Halaster’s home. Twenty-three levels of Undermountain are detailed herein, along with the subterranean refuge of Skullport. Treasures and secrets abound, but tread with care!

A recent earthquake has brought forth ancient evil from beneath the waves, to terrorize a sleepy coastal town. People are disappearing. The heroes will sail to an ancient, steam-powered temple in the ocean. They'll encounter mad fishmen, deadly traps, and ancient horrors that slumbered until now.

When the water source of the city-state of Guerino is poisoned and its citizens enchanted, a group of adventurers must follow the treacherous path deep into Mistfall Mountain and restore balance to the kingdom. Pgs. 91-97

Taag'thrith, born a gith but transformed into an illithid by ceromorphosis, has been finally found purpose: the assimilation & understanding of all knowledge. Taag'thrith plans to unleash a 10th level spell that will grant him just that-at the cost of all sentient life on the Material Plane. Will the heroes be able to traverse the dangerous corpse of a dead God, find Taag'thrith's aqueous lair the Eternal Spirals, & pit their foes against one another in order to destroy the foul lich once and for all? Or will they fall prey to the threats trapped within the Eternal Spirals & sink beneath the surface forever? They Came from the Deep is the second installment in Pretty Little Liches: a trilogy of adventures centered around three unique liches and their lairs designed for high-level play. These three lairs and the surrounding regions can be run independently as individual adventures or tied together into a mini-campaign that centers on the destruction of the Green Hand, an organization of dangerous liches.

A desperate father, a missing girl, and a simple investigation - but nothing is ever simple. As you peel back the layers of mystery, you uncover a dark god, vile sorcery, and a malevolent cult set to unleash horror upon the land... Horror in the House of Dagon is an enthralling and exciting adventure, with lots of role-playing, exploration, and horrifying combat encounters! This adventure is designed for 1st-4th level characters, and will take 3-6 hours to complete.

BLACKTIDE COVE THE CULT OF THE FISH-MEN From the Ship's Log of the Sprite: "...I can hear them fish-men. All the time with their chanting and hissing and whatnot. There's some kind of religion going on here, down below. We can't understand what they say, but it's something God-like, sure as spray on the foc'sle." A century ago, during the Spellplague, pirates hid a treasure at a shrine in a remote area of Impiltur's coast. Can the heroes claim it from that which lurks there? Blacktide Cove is a 4-6 hour adventure for 6 characters of 6th to 8th level set on the Sea of Fallen Stars! Set on the coast of Impiltur along the Easting Reach, Blacktide Cove can be placed anywhere there's a stretch of lonely coastline and the possibility of pirates. Blacktide Cove is 32 pages of adventure for you and your table! Includes a handy index, cartography by Dyson Logos, new magic items, and full-color player handouts - including exclusive art from Patrick E Pullen! Includes print-friendly version!

Agents of the fire giants of Maerimydra, a city in the Underdark, have overtaken the drow outpost of Szith Morcane. The factions seek out adventurers to free the outpost’s leaders for questioning on the giants’ activities. Can you extricate them before it’s too late?

Called by the Elder Elemental Eye to serve, four corrupt prophets have risen from the depths of anonymity to claim mighty weapons with direct links to the power of the elemental princes. Each of these prophets has assembled a cadre of cultists and creatures to serve them in the construction of four elemental temples of lethal design. It is up to adventurers from heroic factions such as the Emerald Enclave and the Order of the Gauntlet to discover where the true power of each prophet lay, and dismantle it before it comes boiling up to obliterate the Realms.

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

The Dark Tide of Damodan is an underwater rescue adventure, where time is of the essence. A mysterious disease is killing of locals and visitors alike in the port town of Havenword. While the adventurers are in town, Havenword is attacked from the sea by nasty fish-headed creatures. After the battle, the characters learn that the creatures dragged off several townsfolk. They have been tasked with finding the captives and returning them safely. The only problem...they were taken out to sea. The characters must delve into the depths into an underwater keep to rescue the captives. Using the knowledge the captives to help locate one another, all the while, avoiding the sinister Damodan's forces. Will the characters turn the tides in their favor? Or will they swim with the fishes? Published by Crit Academy

The recent discovery of an entrance to the Underdark has set local leaders on edge. In a display of initiative, the First Lord of Hillsfar has ordered the construction of defensive structures surrounding what locals have begun to call "The Waydown." You have been charged with escorting an emissary back to his home in the Underdark without alerting the Red Plumes.

A 20-page adventure for OSE Save the wizard! A sunken cathedral on a quiet mountain lake hides a long forgotten temple to Mathanoga, God of Knowledge and wizardry. Abandoned by Man for centuries , but protected by the legend of man-eating fishmen lurking in it. Or until a few weeks ago the young wizad Elric embarked on its expedition. With help from the accademy of Greykeep he found the temple and began to explore it, hoping to uncover its ancient magical secrets. Now the wizard is missing and the accademy has put a bounty on its head: its weight in silver to whoever will find him and bring him home alive and well. Find magical secrets! Deep inside the temple are stashed many magical items, all sacred to the fishmen dwelling there, all worth dying for. Save Elric and the treasures will be yours! The Sunken Temple is an expert level Old School Essentials adventure for a party of 1-4 players. Perfect for a one shot or a random encounter in an hex crawl.

An escaped duergar slave stumbles into the village of Elventree. With her she brings a malady that grips the small settlement in a bout of madness that seems unshakable. Can you find the source of the madness and save yourself and the village’s inhabitants? A four-hour adventure for 5th-10th level characters.

No-one knows why, but many of the villagers of Greenmist have been going insane. Not only that, but something has caused the surrounding environment to transform into fetid swamps. Heroes from far and wide have gone into the swamps to destroy the source of the madness, but none have returned. The truth is that the psychic whispers of an aboleth have invaded the minds of Greenmist's people. The creature called Seedooloo has been using forbidden magic, mad science, and the strange ability of his kuo-toan worshipers to grant himself the power to drive the surface world to insanity. The Call of Seedooloo includes monsters found in Mordenkainen's Tome of Foes.

TENTACLES. WHY DID IT HAVE TO BE TENTACLES? A colony of deep gnomes have had their main water source taken over by a group of kuo-toa, but are the fishy folk really the ones to blame for leaving the gem-loving svirfneblin thirsty?… This adventure was originally made for a West Marches campaign, but is designed to easily fit into any standard fantasy setting. There are many areas to insert plot hooks for your own world or campaign. A 4-hour adventure for 5th-7th level characters by ALAN TUCKER

Nightmares that kill, a mysterious thief that only steals knick-knacks, tales of a huge beast terrorising fisherfolk, an inn with disappearing guests, discoveries of hidden magic portals and rumours of an assassin at large: None of these things are enough to stop the ever-flowing tide of traders and travellers crossing the Bridge of Fallen Men, but its protectors - Cormyr's Purple Dragons - are short on time, and courage... ...will adventurers answer the call?

The characters will investigate a grim mystery in the elven village of Alkai Tor, hunt for answers in a lethal swamp, and finally confront a desperate killer in the Temple of Shattered Minds itself.

"For Blibdoolpoolp!!" "The power of the mind and belief are wonderous, often leading us to manifest things that aren’t real. For the kuo-toa, this power is heightened, allowing their collective belief to manifest gods." Two tendays ago, a paladin of Torm was kidnapped by kuo-toa. In a strange turn of events, she was mistaken for a kuo-toa god, and whisked off to their underground lair. Barria has managed to pose as the god and now shakily leads a small faction of kuo-toa while trapped underground. With her influence being increasingly scrutinized, and with the different kuo-toa sects on the brink of civil war, it’s a dangerous time, even for a ‘god’… The heroes’ mission — rescue the paladin from the kuo-toa oceanic lair before she’s transformed into a kuo-toa god. The kuo-toa are an Underdark-dwelling race of fishlike humanoids. Different sects worship different god-like beings, each god manifested through the strength of a sect’s collective zeal. Such “gods” feature prominently in this adventure. Product Overview ♦ 4 to 8 hours for four to five characters. ♦ Scalable for 3rd-6th level. ♦ High-resolution maps of the Kuo-Toa lair. ♦ 9 new statblocks, including Dire Barnacles and Hypno-Cuddlefish! ♦ Includes plot hooks, handouts, rules for faction combat, and more!