Quests from the Infinite Staircase

AdventureQftIS2014

Chapter 6: The Lost Caverns of Tsojcanth

Deep in the Yatil Mountains lie the Lost Caverns of Tsojcanth (SAWJ-kahn), formerly occupied by the legendary archmage Iggwilv the Witch Queen. Though Iggwilv is long gone, her lair is anything but empty. Demons, dragons, and other formidable creatures haunt the perilous caverns and the mountains that conceal them, and the archmage's untold defenses remain intact. Iggwilv is rumored to have amassed a magical hoard of unsurpassed value, a trove of such fame that scores of adventurers have perished in search of it.

Despite the decades since her disappearance, Iggwilv's impact persists in the caverns, where she is believed to have penned, at least in part, the Demonomicon of Iggwilv: her infamous treatise on the infinite layers of the Abyss and its inhabitants. Abyssal rifts—the byproducts of past magical experiments—leak demonic energy into the tunnels, and guardians bound from faraway planes await rescue or defend the caverns from thieves and trespassers. Other creatures have simply taken up residence in the cave system, adding to its dangers.

"The Lost Caverns of Tsojcanth" is designed for four to six 9th-level characters.

[image: Adventurers clash with the Behir Lludd in his lair within the Lost Caverns of Tsojcanth]

Background

[image: A door to the Lost Caverns]

Iggwilv carved out a kingdom for herself through magical prowess, strength, and wit, bolstered by a horde of demons bound by magic to further her aims. In her quest for absolute power, Iggwilv accumulated countless enemies determined to destroy her. Among these was the demon lord Graz'zt, whom the archmage imprisoned for a time. Eventually, Iggwilv's ambitions proved excessive, and a climactic battle with Graz'zt broke her power. The Witch Queen then vanished. As her evil influence waned, Iggwilv's realm was sundered, and her lair, the Caverns of Tsojcanth, was lost.

This lost lair purportedly lies deep in a series of caverns somewhere in the Yatil Mountains. Clues to the lair's whereabouts and fragments of the treasures within have surfaced over the last few decades, and three nations that border the mountains where it hides now race to claim Iggwilv's hoard—or, if they can't claim it, at least ensure that their rivals don't either.

The margrave of a nation near the mountains has promising leads on the location of the caverns, thanks to a few expeditions in recent years. Most of the agents the margrave sent out never returned; others came back battle worn and empty-handed, save for harrowing tales of the horrors in the caves. The margrave now seeks adventurers made of sterner stuff undertake the quest.

Using the Infinite Staircase

If you're using Nafas as a patron, he summons the characters to the x (detailed in chapter 1), where he recounts the following wish:

Nafas then teleports the characters to a door along the Infinite Staircase that opens into a roadside inn near the Yatil Mountains, where a ruler searching for the Lost Caverns has placed an agent to recruit for the venture. After the adventure, the characters can return to the staircase via the same portal.

Adventure Hooks

If you're not using Nafas as a group patron, consider the following ways to involve the characters in this adventure:

  • Lost Light. A powerful curse plunges a nearby nation into strife. Rumor claims the light of Daoud's Wondrous Lanthorn is the key to breaking the curse. A ruler who believes the lantern is in the Lost Caverns sends an agent to recruit the characters to retrieve it.
  • Racing Rivals. The margrave of a land near the Yatil Mountains seeks to weaken his political rivals without drawing suspicion. Having heard of the party's exploits, he hires the characters as independent agents to find Iggwilv's lair and its potent treasures before the forces of neighboring nations find them.

Setting the Adventure

On the world of Oerth in the Greyhawk campaign setting, the Lost Caverns hide within in the southern Yatil Mountains, nestled between the nations of Ket and Perrenland, with Bissel to the south. The margrave of the March of Bissel has uncovered clues to the Lost Caverns' location.

You can set the adventure in a different world by placing it in any mountain range near a kingdom or settlement—before her disappearance, Iggwilv's influence spanned multiple worlds and planes of existence. Consider the following suggestions:

  • Eberron. The nations of Aundair, Breland, and Thrane vie to explore the Lost Caverns in the Blackcap Mountains. Iggwilv's experiments there drew power from the depths of Khyber.
  • Forgotten Realms. The Lost Caverns are hidden in the Sunset Mountains, northeast of Proskur along the High Road. The High Overseer of Elturel hires the characters to locate the caverns.

Adventure Summary

"The Lost Caverns of Tsojcanth" begins with a meeting between the characters and an agent serving the margrave of a nation whose rivals surround the x, where the Lost Caverns are believed to be hidden. Whether the margrave covets one of Iggwilv's treasures for himself, seeks to sponsor the adventurers, or wants the characters to prevent his rivals from claiming the hoard first, the agent offers what little information they have about the caverns' whereabouts.

While navigating treacherous mountain passes, the characters must avoid rockslides, contend with roaming monsters or the patrols of the rival nations, and perhaps encounter friendly faces as they search for the entrance to the Lost Caverns. Danger-filled caverns await the characters in Iggwilv's former lair. Bloodthirsty monsters and the deadly remnants of the archmage's power stand between the characters and the Witch Queen's hoard, which is guarded by the greatest of Iggwilv's treasures—her daughter, the vampire warrior Drelnza.

Character Advancement

If you want to use story-based level advancement, the characters receive experience points for achieving the following milestones rather than defeating monsters:

  • Entering the Greater Caverns. The characters gain 1 level when they enter the greater caverns for the first time.
  • Encountering Drelnza. After the characters encounter the vampire Drelnza for the first time, everyone in the party who survives the encounter gains 1 level.

If you follow this method, the characters should reach 11th level by the adventure's conclusion.

Starting the Adventure

The settlements nearest to the Lost Caverns are several days' travel from the x, though way stations, hunting lodges, and roadside inns dot the roads up to the mountains. An agent waits to receive the characters at the last of these inns, a miserable joint named the Lazy Bat.

The Margrave's Agent

[image: The hooked peak of Iggwilv's Horn towers over the rest of the Yatil Mountains]

However the characters take on the adventure, they eventually arrive at the Lazy Bat, where they meet an agent who serves the Margrave of the March of Bissel. Read or paraphrase to begin the adventure:

The agent, Bannik Vorl (lawful neutral, human spy), can offer the following details:

  • Bannik's Employer. Bannik avoids naming their employer, but if pressed for proof flashes a seal bearing Bissel's crest: a white-and-red shield with a black tower emblem. A character who sees the symbol and succeeds on a DC 13 Intelligence (History) check recognizes the symbol.
  • Lost Caverns. The Lost Caverns were once the lair of an archmage named Iggwilv. The archmage is long gone, but her treasure remains. Most who set out to find the caverns come back empty-handed or are never heard from again.
  • Travel Arrangements. If requested, Bannik can supply each character with a sure-footed riding horse and ten days of rations.
  • Treasure. The characters are free to keep whatever treasure they find, minus a 10 percent finder's fee to be paid to Bannik and one specific item to be delivered to the margrave: Daoud's Wondrous Lanthorn. The margrave is most concerned with ensuring his rivals don't get the treasure, but the lantern is of special interest.

Iggwilv's Verse

The scroll provided by Bannik contains a map of the x and a scrap of parchment scribed with the following verse:

The map is an accurate—albeit basic—representation of the mountains and the main roads that run through them. It doesn't depict smaller trails, including the path to the Lost Caverns. The verse hints at the location of the caverns (see the "x" section later in this adventure).

Yatil Mountains

The Yatil Mountains are a rugged mountain range that separates the nations of Ket and Perrenland. The peaks are rife with danger and impassable by unseasoned travelers. The characters must trek through the mountains to find the lost dungeon.

To the north, a singular, imposing peak with a hooked summit rises above the others: Iggwilv's Horn. Characters might be tempted to head toward it, believing the Lost Caverns must be located near a mountain named for the Witch Queen, but a clue on Bannik's scroll warns them off this course (see the "Iggwilv's Verse" section).

Map 6.1 depicts the Yatil Mountains. Obstacles along the mountain's main roads are rare, but once off the roads it's a different story. Any hex on the map that doesn't contain a road is difficult terrain for overland travel.

Mountain Encounters

While the characters are exploring or camping in the Yatil Mountains, roll a d20 three times per day of game time, checking for encounters each morning, afternoon, and night. An encounter occurs on a roll of 16 or higher. Alternatively, map 6.1 offers suggested locations where encounters might occur. To determine what the characters find, roll on the Mountain Encounters table, rerolling duplicates.

Mountain Encounters

d8Encounter
1x
2x
3x
4x
5x
6x
7x
8x

Border Patrol

A group of human soldiers from a nation bordering the mountain range travels the road. A captain (use the gladiator stat block) leads two knights and six guards. All the soldiers are lawful neutral. Their orders are to catch brigands and smugglers, drive monsters from the roads, and prevent raids.

The soldiers are initially suspicious of the characters. However, if the characters explain their business in the mountains and succeed on a DC 15 Charisma (Persuasion) check, the soldiers invite the characters to camp with them for the night. On a failed check, the soldiers dismiss the characters and continue their march.

The soldiers spend each evening sharing stories around the campfire—including one harrowing tale about a vampire named Drelnza who once terrorized the neighboring nation of Perrenland. The vampire was never vanquished, and to this day, the soldiers dare to speak her name only in hushed tones. (Drelnza is further detailed in x.) Consider awarding inspiration to characters who share a story in return. If the characters camp with the soldiers, the soldiers keep watch so they don't have to.

Dragon Flight

Berythrach, a young blue dragon, recently made her lair in a rugged valley between two low peaks. The dragon has been raiding the surrounding lands in ever-widening sweeps, expanding her territory.

Berythrach soars overhead, scouring the mountains for prey. The characters can make a DC 17 Dexterity (Stealth) group check to evade the dragon's gaze, doing so on a successful check. On a failed check, the dragon notices the characters and begins circling their location, swooping lower with each pass. A vain dragon, Berythrach expects the characters to cower before her grandeur or offer her treasure in exchange for safe passage.

If the characters don't attack Berythrach, she lands on a rocky outcropping and engages them in conversation. If the characters offend the dragon, she falls on them with bare fangs and sharp claws.

What Berythrach Knows

Berythrach knows the routes of several border patrols, as well as the locations of a x, a x, and a x (detailed in the encounters that follow).

Berythrach also knows the approximate location of the Lost Caverns of Tsojcanth—or at least how to find them. Great tides of bats emerge from the caverns at dusk and return to them at dawn. If the characters give Berythrach treasure worth 1,000 gp or a rare or better magic item, the dragon shares this fact and points the characters in the right direction. She then advises them to follow the bats, adding a few barbs about how they'd be doomed without her generosity and wisdom.

Fire Giant

A fire giant lumbers through the mountains, seeking revenge on a group of trolls that stole a hammer from the giant's forge. The giant is indifferent toward the characters and informs them of the trolls' theft. If the characters hunt down the trolls and return with the stolen hammer (see the "x" encounter), the fire giant uses it to craft them a Flame Tongue sword of their choice; this process takes 1d4 days.

The giant doesn't know the location of the Lost Caverns but suspects other local inhabitants might.

Gnome Vale

A small track branches off from a main road toward a narrow canyon. The canyon widens into a small, secluded vale with meadows dotted with spring-fed ponds and stands of trees. The valley is home to a reclusive community of mountain-dwelling gnomes. The gnomes raise goats and sheep in the valley and mine metals in the surrounding bluffs.

Five guards (lawful neutral, gnome scouts) watch the canyon entrance at all hours. If the characters approach in a peaceful manner, one of the scouts runs back to the vale to fetch their leaders, Laira Na'Gwaylar (lawful good, gnome veteran) and Saleen Glimmershade (neutral, gnome druid).

Laira and Saleen greet the characters and inquire as to their business. Laira is terse and to the point, though she's not rude. Saleen is quiet and listens intently, but when she speaks, her voice holds authority and confidence.

Stolen Steel

A group of trolls recently stole a crate of steel ingots from the gnomes. If the characters retrieve the ingots from the trolls (see the "x" encounter), the gnomes promise to reward the characters and divulge what they know of the Lost Caverns. On the characters' triumphant return, the gnomes pay the characters half the ingots' worth in gems (250 gp total) and reveal the information in the following section.

What the Gnomes Know

Saleen has heard local bats whisper about magical caves that come alive and swallow up intruders. She knows where the caverns are located and can point the characters in the correct direction, but she and the other gnomes avoid the area.

Hermit

A nameless, wizened hermit (neutral good, human archmage) lives in a simple hut in a wooded grove not far from one of the roads. He's been here as long as anyone can remember, seeking enlightenment in his solitude. Dirty and disheveled, the hermit dresses in simple, homespun clothing and carries no weapons, though he wears an invisible Ring of Mind Shielding to protect his thoughts.

Occasionally the hermit sits on a flat rock near the road, contemplating the empty path or just enjoying the sun on his withered frame. He gratefully accepts donations of food, fuel for his fire, or warm clothes in exchange for information.

What the Hermit Knows

The hermit is a calm and cheerful fellow. He gently responds to anyone who happens by, but he doesn't speak unless spoken to. If asked his name, the man simply replies that he "left it behind a long time ago."

The hermit can share the following information with the characters:

  • Iggwilv's Horn. The tall, hooked mountain that rises above the Yatils is called Iggwilv's Horn. Many think the Lost Caverns are beneath it, but they're wrong.
  • Location of the Lost Caverns. The hermit believes the caverns lie to the south. Long ago, when the hermit was young and Iggwilv controlled the region, he witnessed much activity in that direction.
  • Planar Nexus. Rumor has it the caverns are a nexus of planes, and many monsters now inhabit them. The caverns have more than one level.

Rockslide

A faint splintering sound echoes overhead as rocks clatter down the mountainside toward the party. Creatures on that side of the mountain must make a DC 15 Dexterity saving throw. On a failed save, a creature takes 22 (4d10) bludgeoning damage and has the prone condition, pummeled to the ground by the falling rocks. On a successful save, a creature takes half as much damage only.

Troll Cave

The characters happen on a shallow cave not far from one of the mountain roads. Inside, three trolls pick at the remains of a giant goat. The trolls are hostile and hungry, warning trespassers to leave or become their next meal. If two trolls are slain, the last of them surrenders.

What the Trolls Know

If the characters attempt to parley with the trolls, they learn the trolls are former residents of the Lost Caverns ousted from their den by their clan. If the characters agree to slay the trolls' estranged cohorts (see x of the Lost Caverns, detailed later in this adventure), the trolls divulge the entrance to the fabled dungeon.

Treasure

The trolls' accumulated loot is stashed under a pile of rank, uncured bear pelts in their cave. It includes the following: a crate of 50 steel ingots, each worth 10 gp and stamped with a Gnomish insignia; a forge hammer sized for a giant that functions as a warhammer for Medium creatures; and assorted coins worth a total of 250 gp.

Wyvern Roost

Two wyverns roost in a crevice atop a 100-foot-tall spire 1 mile from the road. They have a clutch of three eggs in their nest and are fiercely territorial of the surrounding area as a result. The wyverns take turns hunting and watching the eggs. When the characters near the roost, roll a die. On an odd number, only one wyvern is in the nest; on an even number, both wyverns are present.

Treasure

The wyverns' eggs are valuable to those who want to raise the hatchlings as mounts or guardians (and who are willing to brave the dangers of training them). Each egg fetches up to 500 gp from an interested buyer.

Lost Caverns

The Lost Caverns of Tsojcanth hide in the x south of Iggwilv's Horn. Not much is known about the caverns' namesake, the mysterious Tsojcanth, who was eclipsed by the archmage who succeeded them. Whether Tsojcanth was slain by Iggwilv or left before her arrival, this predecessor's only remaining trace is the caverns' name, while the Witch Queen's influence persists long after her departure.

The caverns are divided into the lesser and greater caverns.

Finding the Caverns

[image: A ghastly visage outside the entry caverns portends the dangers within]

The entrance to the Lost Caverns lies in the southern region of the x (denoted on map 6.1). A small track that was once a wider, more traveled road leads to the entrance, but over the decades it has been obscured by rockslides and neglect.

The scroll given to the characters by Bannik (see the "x" section) hints the characters should turn their backs to Iggwilv's Horn, meaning they should search to the south. From there, they can find the caves using the following methods:

  • Ask Around. A few of the mountains' inhabitants—including Berythrach, the hermit, and Saleen Glimmershade—either know where the entrance is or have information that points the characters in the right direction. By conversing with these creatures, the characters can narrow their search.
  • Follow the Bats. Thousands of bats fly out of the Lost Caverns at dusk to hunt and return at dawn to roost in the darkness. Characters who observe the bats and succeed on a DC 15 Intelligence (Nature) check realize there must be a massive cave nearby for the colony to roost in. Characters who follow the bats eventually arrive at the entrance to the Lost Caverns. Alternatively, characters who have a means of speaking with Beasts can obtain directions to the caverns from the bats.
  • Trial and Error. By diligently searching the roads and tracks in the Yatil Mountains, the characters can eventually locate the entrance to the caverns. However, this painstaking option could result in additional mountain encounters and a lengthy journey, depending on what path the party takes through the mountains.

The entrance to the caverns is a yawning cleft in the mountainside. Sharp rock formations at the entrance give the cave mouth the impression of fangs waiting to snap together. The opening is 40 feet wide, 20 feet high, and blackened by soot. Past the stone maw, a wide passage with roughly hewn stairs slants down to the hideous, stone-carved faces of the entry caverns (x of the lesser caverns).

Lesser Caverns Features

Unless otherwise noted, the lesser caverns have the following features:

  • Ambience. The caverns are damp, humid, and full of life. They echo with the sounds of bats, dripping stalactites, and the cavern's monstrous denizens.
  • Ceilings. Ceilings are 15 feet high in corridors and tunnels and 20 feet high in chambers.
  • Lighting. The caverns are unlit. Denizens carry their own light or rely on darkvision to see. Area descriptions assume the characters have a light source or other means of seeing in the dark.
  • Underground Rivers. The rivers that span the lesser caverns have strong currents. A creature that enters a river for the first time on a turn or starts its turn there must succeed on a DC 15 Strength saving throw or be swept 15 feet in the direction indicated by the arrows on the map.

Lesser Caverns Locations

The following locations are keyed to map 6.2.

L1: Entry Caverns

The carved faces are magical. They are immune to all damage and speak a few programmed messages. When a creature approaches one of the tunnels, the face beside it animates and warns in a deep, dire tone, "Turn back—this is not the way!"

A character who examines one of the faces and succeeds on a DC 15 Wisdom (Perception) check notices the glint of a gemstone in its mouth.

Speaking to the Faces

The faces repeat their warning if a spoken to, except in the following two circumstances:

  • "Say 'Aah!. '" If a character asks one of the faces to open its mouth, stick out its tongue, or yawn, the face sticks out its tongue and says "aah," revealing a gemstone the size of a hen's egg on its tongue.
  • "Truth. " If a character asks one of the faces which way to go or uses the word "truth" while speaking in this area, the faces respond in unison. Five of the faces lie, saying, "My way is the right way." The face marking the southeast tunnel leading to x, however, responds, "I watch the best way."

Treasure

Each of the faces contains a different gem worth 200 gp: amber, amethyst, blue aquamarine, garnet, peridot, and pink tourmaline.

A creature that tries to retrieve a gem from one of the faces without first asking the face to open its mouth must make a DC 17 Dexterity (Sleight of Hand) check. On a failed check, the creature takes 11 (2d10) bludgeoning damage as the mouth clamps shut. The mouth similarly damages tools or weapons inserted into it without its permission.

L2: Streaked Cave

Twenty stirges hang from the ceiling of this cave. Bright light or any noise louder than a whisper disturbs the stirges, causing them to attack.

L3: Slate Chamber

The figure is a clay golem created by Iggwilv to destroy intruders. The golem attacks any creatures that enter the chamber. The golem fights to the death and pursues trespassers relentlessly, even chasing them out of the caverns.

Treasure

The weapon stuck in the clay golem is a slender-bladed Giant Slayer (shortsword). The sword's name ("Longtooth") is engraved into the blade in Gnomish. Once the golem is destroyed, the sword can easily be freed from its chest.

L4: Guano-Covered Cave

The ceiling of this soiled cave is 50 feet high. This cave once hosted dozens of bats, but a cloaker that dwells here devoured them. The hungry creature hides among the stalactites, waiting to fall on one of the characters.

Tunnel Ledge

A ledge on the north wall of the cave stretches out 30 feet above the floor. A short tunnel leads from the ledge to the river beyond. The water's surface is 40 feet below the tunnel's exit.

L5: Littered Cave

The skeleton is that of a minotaur thief who fell prey to the trap in this cave. The two leather sacks beside it are illusions designed to lure greedy intruders to their doom. A character who inspects the sacks and succeeds on a DC 18 Intelligence (Investigation) check or who makes physical contact with one of them discerns their false nature.

Crushing Ceiling Trap

A 20-foot-wide section of the ceiling over the skeleton contains a crushing deadfall. A character who examines the ceiling and succeeds on a DC 17 Wisdom (Perception) check notices bits of decayed flesh stuck to the ceiling, which is flat and made of stone.

Whenever a creature enters the area marked on the map, the trap magically triggers. That section of the ceiling rapidly drops, crushing anything in its path. Creatures in that area must make a DC 17 Dexterity saving throw. On a failed save, a creature takes 55 (10d10) bludgeoning damage and has the prone condition. On a successful save, it takes half as much damage only and is pushed to the nearest unoccupied space outside the trap's area. Objects wedged under the trap are destroyed. The stone then retracts into the ceiling, and the trap resets.

A successful Dispel Magic spell (DC 17) suppresses the trap and its illusions for 24 hours.

Treasure

A pouch on the minotaur's skeleton holds five diamonds worth 100 gp each. The illusory sacks contain nothing.

L6: Grotto

[image: Four pechs diligently dig a staired tunnel up into the mountain, decorating its walls with carvings]

Eight pechs are diligently carving a tunnel from this grotto up into the mountain toward an enclosed cavern they can sense. For now, the tunnel leads only to a dead end. If the characters draw attention to themselves with light or noise, the pechs investigate.

The pechs are initially indifferent toward the characters, admonishing them to douse any bright lights they carry, as the lights hurt the pechs' eyes. If the characters comply, the pechs become curious and willing to chat. Otherwise, they resume their work, defending themselves if necessary.

In conversation, the pechs warn the characters about the clay golem in the slate chamber (x). Characters can improve the pechs' attitude toward them by offering the pechs at least 500 gp of gems or a unique carving or sculpture, especially one made of stone. Friendly pechs might be willing to help fight the clay golem or use their Communal Spellcasting to restore petrified characters.

Carvings

The carvings on the walls depict cave-dwelling creatures such as bats and reptiles, as well as creatures from the Elemental Plane of Earth such as dao, pechs, xorn, and earth elementals. Characters who inspect the carvings and succeed on a DC 16 Intelligence (Arcana) check identify the planar creatures.

L7: Fungal Cavern

Three ghost-white cave crickets (use the giant frog stat block) nibble at the glowing mushrooms in this cave, which radiate dim light. The crickets are indifferent toward the characters.

If the characters disturb the crickets, the insects begin to chirp loudly. The trolls in x investigate any loud noises in this area.

Mushrooms

The fungi in this cavern are edible, and characters can forage here without having to make an ability check. Doing so doesn't disturb the crickets.

L8: Slimy Cavern

Originally this was another cultivated fungus farm like x, but slime molds are overtaking the cave. The cloaked figure is the corpse of an elf adventurer who died here, trapped by the green slime. His body has been partially calcified by the mineral-rich water dripping from the ceiling.

Green Slime

Six patches of green slime (see the Dungeon Master's Guide) cling to the ceiling near the fallen adventurer. A character who inspects the slime and succeeds on a DC 15 Intelligence (Nature) check recognizes the danger it poses. The slime falls on creatures that approach the corpse.

Mushrooms

The fungi here are mostly edible. Foraging in this cavern requires a successful DC 15 Wisdom (Survival) check to avoid the harmful molds and slime. On a failed check, the mushrooms the character gathers are contaminated by the slime. A creature that eats a contaminated mushroom must succeed on a DC 12 Constitution saving throw or have the poisoned condition for 8 hours.

Treasure

The elf corpse carries a silvered rapier and wears Bracers of Defense.

L9: Stinking Cave

[image: Three hungry trolls pass the time in their foul-smelling cave]

This cave is the lair of three trolls. They regularly gather rotting material from their den and spread it through the nearby fungus caverns (x and x) to ensure the mushrooms grow and attract cave crickets for the trolls to feed on. The trolls are ornery, having long gone without the taste of humanoid flesh—their favorite delicacy. The trolls attack anyone they notice, fantasizing aloud in Giant about the meal they're about to have.

The trolls the characters might have met in the mountains (see the "x" section earlier in this adventure) were ousted by these trolls.

Treasure

Gathered under the trolls' beds is their accumulated loot: 120 gp, 900 sp, four gems worth 50 gp each, wooden dentures set with mother-of-pearl teeth (worth 50 gp), a quiver with twenty silvered arrows, and a Potion of Healing (greater).

L10: Bat Corridor

During the day, the ceiling of this corridor is covered in thousands of bats, and a cacophony of chitters and squeaks echoes from above. At night, the bats flood out of the caverns to hunt in the mountains, returning to this area at dawn.

While the bats are roosting, bright light or any noise louder than a whisper agitates them and sends them into a panic. A number of swarms of bats equal to the number of characters in this area descend from the ceiling and attack the source of the disturbance. The swarms extinguish any nonmagical light sources they come within 5 feet of with a flurry of buffeting wings.

Whenever a creature destroys a swarm, a new swarm immediately forms in an unoccupied space within 15 feet of the creature. The new swarm acts on the destroyed swarm's initiative count.

If the characters extinguish all light sources and cease attacking and making loud noises, the bats settle back into their roosts at the end of the round. They don't pursue creatures beyond the corridor.

L11: Long Gallery

The indentations are the rock-cyst burrows of four cave morays—sluglike scavengers that slither between the burrow entrances through tunnels in the rock. The cave morays use the giant poisonous snake stat block. They use their reach to bite at prey from the safety of their burrows.

Cave morays inside their burrows have three-quarters cover. A creature within 5 feet of a burrow can pull a cave moray from its burrow by grappling it. If removed from its burrow, a cave moray frantically tries to escape back to its hole.

Loud sounds here, including the din of battle, draw the attention of the fomorians in x. The cave morays retreat into their burrows when the fomorians arrive.

L12: Fomorian Cave

Two fomorians inhabit this cave. The beds, fire pit, and utensils are all sized for Huge creatures.

The fomorians are cruel, violent, and bored. When the giants notice the characters, they abandon their meal and attack. One of the fomorians wields the roasting spit as its weapon, tearing bites off the bug-tipped skewer between swings.

Treasure

Stashed beneath the fomorians' beds are two ivory mammoth tusks (each is worth 600 gp and weighs 100 pounds), a Spell Scroll of Levitate, and a beaten copper bowl with lapis lazuli handles, which is worth 750 gp.

L13: River Ledge

This ledge is visible from the lake (x) and the shores of x and x.

Treasure

The vessel is a Folding Boat created to traverse the lake and the rivers that branch from it. In addition to its usual properties, the boat has an extra command word that functions only while the boat is within the Lost Caverns. A character who knows this extra command word ("Shrimpkin")—discovered by casting the Identify spell on the boat or by examining clues in the boat's intricate designs and succeeding on a DC 16 Intelligence (Arcana) check—can command the boat to row itself in a particular direction at a speed of 30 feet or to hold its position in defiance of the water's swiftest currents.

L14: Underground Lake

The lake teems with blind cave fish and crayfish. These critters are a food source for many of the denizens in the lesser caverns, including predators that dwell within the lake itself. The lake slopes sharply from its shores to a depth of 100 feet.

Four chuuls lurk near the lake bed, 90 feet below the surface. They're content to creep along the lightless depths and prey on cave fish unless something else catches their attention. Bright light draws the chuuls to the water's edge, as does any magic in the lake or near its surface, such as the boat from x. If drawn to the surface, the chuuls attack.

L14a: Stone Bridge

An unadorned stone bridge spans the northwest river.

L14b: Gargoyle Bridge

A bridge decorated with reliefs of gargoyles spans the west river flowing from the lake. The sound of roaring water echoes from downstream. A short distance beyond the bridge, the river becomes a waterfall, plummeting 300 feet into an Underdark lake. The lake and the creatures that inhabit it are beyond the scope of this adventure, but you can flesh them out as you see fit.

L15: Basilisk Den

Four basilisks dwell in this cave. Toward the back of the cave is a nest where the basilisks lay eggs. The basilisks are protective of their den, attacking any creatures that enter the cave.

Treasure

The head and shoulder of a petrified gnome lie near the basilisk nest at the back of the cave. The broken statue wears a pair of unpetrified goggles, which are Eyes of Minute Seeing.

L16: Rainbow Cavern

This colorful cavern is the lair of a chimera named Chossos and a gorgon named Fossus. Chossos speaks Common, Draconic, and Giant. He resembles a typical chimera, except he has a bull head in place of a goat head. This head confers no special abilities on Chossos, but it has helped him foster a kinship with Fossus.

When they aren't hunting together, Fossus restlessly paces among the cavern's vibrant stalagmites, while Chossos rests on a ledge above the entrance, from which the chimera ambushes any who pass by. The two creatures work together to burn, petrify, and trample intruders.

If Chossos is reduced to 50 hit points or fewer, the chimera feigns surrender and vows to give the characters his treasure if they spare him. If Fossus is still alive, Chossos calls off the gorgon. Chossos then attempts to lure the characters closer before resuming his assault once they've dropped their guards.

Treasure

The remains of a petrified adventurer stand among the stalagmites. A Bag of Holding hangs from the drab statue, which is missing its head. The bag contains a set of robes, 9 days of rations, a lacquered pipe, and a scorched spellbook containing the following spells: Darkvision, Fog Cloud, Grease, Identify, and Web.

Piled atop the ledge above the entrance is a small heap of treasure containing 900 gp and 700 sp.

L17: Boulder Heap

The boulders are obviously not a natural formation. Chossos (see x) piled them here to block the entrance to the greater caverns and prevent creatures that dwell there from taking him by surprise.

With 5 minutes of work, the characters can clear enough of the rocks to expose the tunnel beyond. There, a flight of nine hundred crudely shaped stone steps descends to x of the greater caverns (detailed later in this adventure).

Hollow Boulder

If the characters move any of the rocks, they uncover a smooth, blue-green boulder that's strangely light and clunks dully when moved or shaken, revealing its hollowness. The boulder can be easily broken open with blunt weapons, with tools, or by smashing it against a hard surface.

Graven Glyphs

Inside the hollow boulder is a bronze tablet worth 100 gp. The tablet is etched with a poem meant for those bold enough to delve into the greater caverns. It offers cryptic insight on how to enter Iggwilv's inner sanctum (x), where the archmage's true prize resides. The poem reads as follows:

L18: Lavish Parlor

This area is brightly lit. The nobles kindly invite the characters to join the repast, insisting they rest and regale the nobles with tales of adventure.

The nobles are part of an elaborate, genie-wrought illusion created by Kashem, a bitter dao bound to guard this chamber by Iggwilv. The Witch Queen imparted a mote of her power to Kashem in exchange for the dao's services. Long after the archmage's departure, Kashem still pursues her original charge to destroy all who enter.

When the characters arrive, Kashem floats silently above the chamber, waiting for a prime opportunity to strike. If the characters consume any of the food or drink, refuse to join the nobles outright, or see through the illusions, Kashem reveals herself and attacks.

Dust to Dust

If Kashem is slain, her body disintegrates into a pile of fine dust. This dust can be used in x to destroy the cage in the lake or prove that Kashem is dead.

Illusory Finery

The room's furnishings and inhabitants are convincing, genie-wrought illusions. These illusions blanket dingy, neglected versions of the objects they cover and feel real if touched. To pierce the dao's ruse, a character examining the chamber's fixtures must succeed on a DC 20 Intelligence (Investigation) check. The nobles, however, fail to hold up to physical inspection. A character who touches a noble automatically succeeds on this check.

Poisoned Feast

The food and drink on the table are real—and poisoned. A creature that consumes any of the food or drink must make a DC 16 Constitution saving throw. On a failed save, a creature takes 21 (6d6) poison damage and has the poisoned condition for 1 hour. On a successful save, the creature takes half as much damage only. The illusory nobles nonchalantly partake of the sumptuous feast and politely encourage the characters to sample the dishes.

Treasure

None of the treasure is real. Coins and precious objects taken from the chamber turn out to be flat stones and obvious counterfeits.

L19: Black-Water Lake

The island is strewn with tiny garnets, which sparkle alluringly in the presence of light.

Lurking Death

Eight aquatic ghasts (each has a swimming speed of 30 feet) lurk in the lake, which is 20 feet deep. Spotting them beneath the water's mirrorlike surface requires a successful DC 20 Wisdom (Perception) check. The ghasts ambush any creatures that enter the lake.

Rebuking Island

Iggwilv recorded a series of messages in this cave to taunt intruders. Each time a creature sets foot on the island, an imperious feminine voice echoes throughout the cave, uttering one of the following reproofs:

  • "Fools! This is a dead end. Flee while you still can!"
  • "You were witless to enter at all, so you should probably just stay here."
  • (Peals of hideous, mocking laughter)

Treasure

Six hundred garnets are strewn across the island, each the size of a pea and worth 1 gp. It takes 10 minutes for a creature to collect the gems by hand. They have a combined weight of 5 pounds.

L20: Cave of Crystals

Three xorn from the Elemental Plane of Earth found their way to this cave through a planar rift that has since closed, stranding them here. The xorn are initially indifferent to the characters but defend themselves if attacked.

Hungry Castaways

The xorn are discussing their plight when the characters arrive. The creatures are hungry and upset at their situation. Prone to stress-eating, the xorn crave any precious gems or metals they can sense on the characters. If anyone in the party can understand the xorn, the creatures explain their dilemma and attempt to persuade the characters to give them a meal of at least 100 gp worth of gems or metals per xorn.

If the characters have a means to send the xorn home—such as the Banishment spell—the xorn offer to help locate other treasure for the characters as payment. Alternatively, a character can convince the xorn to assist them in defeating a single threat elsewhere in the caverns with a successful DC 18 Charisma (Persuasion) check.

Treasure

The xorn stashed 500 gp worth of uncut gems behind a large crystal formation in the northwest corner of the room. A character searching the crystals finds the stash with a successful DC 17 Wisdom (Perception) check.

L21: Pool Cavern

The river dead-ends in this flooded chamber. A marid named Kasdu'ul is trapped at the bottom of the pool, 30 feet below the surface. An unbreakable stone cage etched with glowing runes confines the genie to the pool. Characters who look into the pool and succeed on a DC 15 Wisdom (Perception) check notice the cage's faint, glimmering light in the water.

Bound Genie

Kasdu'ul was trapped here by the dao Kashem (see x) centuries ago, shortly before Kashem was fooled and bound by Iggwilv in turn. A permanent Antipathy/Sympathy spell (save DC 18) protects the cage and repels creatures that aren't native to the Elemental Plane of Earth with its Antipathy effect. The runes on the cage invoke the hatred of Ogrémoch, the Prince of Evil Earth.

While the cage is intact, Kasdu'ul has the incapacitated condition and speaks in a lethargic tone. If the characters overcome the Antipathy effect and approach the cage, the genie drowsily asks them to destroy it.

Destroying the Cage

The cage is immune to all damage and has no locks or opening mechanisms. It can be destroyed in the following ways:

  • A creature native to the Plane of Earth—such as one of the pechs in x—can easily break the cage as if it were made of fragile clay.
  • If the dust of a slain dao is scattered over the lake, the cage instantly rusts away.
  • A successful Dispel Magic (DC 18) spell cast on the cage causes it to crumble.

Kasdu'ul has had many years to contemplate the cage's magical construction. She might propose one of these methods to the party from inside the cage.

Freed Genie

If the cage is destroyed, Kasdu'ul returns to her lively self. The grateful genie urges the characters to find and slay the dao that imprisoned her if they haven't already.

As thanks for freeing her, she's willing to cast Tongues, Water Breathing, and Water Walk on the characters to facilitate their exploration. If the characters also present proof of Kashem's demise—such as a pinch of the dust left behind after her death—or they offer a convincing story and succeed on a DC 17 Charisma (Deception) check, Kasdu'ul summons a water weird and orders it to serve the characters for 1 hour, after which it vanishes. In either case, Kasdu'ul then bids the characters farewell and returns to the Elemental Plane of Water.

Greater Caverns Features

Unless otherwise noted, the greater caverns have the following features:

  • Ceilings. Ceilings are 15 feet high in corridors and tunnels and 30 feet high in chambers.
  • Corrupted Region. Abyssal energy bleeds into the greater caverns. Phantom whispers and twisted shadows pluck at the characters' fears, and nightmares plague their rest. A character who finishes a long rest in the greater caverns must make a DC 15 Wisdom saving throw. On a failed save, the character gains only the benefits of a short rest.
  • Lighting. The caverns are unlit. Denizens carry their own light or rely on darkvision to see. Area descriptions assume the characters have a light source or other means of seeing in the dark.

Greater Caverns Locations

The following locations are keyed to map 6.3.

G1: Warren Tunnels

The stench permeating these shallow tunnels arises from the compost and manure in the carefully tended fungus beds.

The tunnels are home to a clan of troglodytes warped by demonic energy radiating from Iggwilv's experiments. Eighteen troglodyte warriors live in the warrens. The clan is led by a bloated hezrou servant of Laogzed, a lesser demonic deity of mindless gluttony venerated by these troglodytes. Blessed by Laogzed, the troglodytes are immune to the poisoned condition.

Foul Welcome

Six troglodyte warriors lurk near the entry, waiting to ambush creatures arriving from the lesser caverns. The characters can sneak past the troglodytes with a successful DC 15 Dexterity (Stealth) group check. Characters carrying a light source have disadvantage on this check. If combat breaks out here, the hezrou joins the fight on initiative count 20 of the second round (losing initiative ties). Six more troglodytes arrive on initiative count 0 of the third and fourth rounds.

Treasure

The hezrou's chamber contains a Potion of Healing (greater) and a Sword of Vengeance (longsword).

G2: Cavern of Corpses

The calcified corpses include dead explorers, troglodytes, and cave-dwelling creatures. A wicked spirit of hunger (use the wraith stat block) resides here, a sliver of the lesser god Laogzed's power. The troglodytes worship this ravenous spirit and offer up captives and treasure to it as sacrifices. Seven specters created by the spirit lie dormant in their former bodies, awaiting its command.

When the characters enter the cavern, the spirit and specters attack, eager to feed off the characters' life force.

Treasure

Scattered on the floor at the far end of the chamber are 480 gp, 800 sp, twenty assorted gems worth 50 gp each, and a sealed scroll tube with a Spell Scroll of Raise Dead.

[image: A spirit of hunger emerges from a wall of calcified corpses to devour the souls of the living]

G3: Great Gallery

The ceiling of this long cavern rises to a height of 50 feet. Careful examination of the floor reveals many cracked bone fragments among the fungi. This is the lair of Lludd, a clever and long-lived behir who speaks Common and Giant in addition to Draconic. Lludd lurks on a ledge near the entrance to the chamber, waiting for morsels worthy of his hunger.

Lludd is hostile toward intruders, but he doesn't immediately resort to violence. Though he's selfish and cruel, the behir hasn't survived this long by attempting to devour every creature that enters his lair—especially hardened adventurers. When he notices the characters, Lludd greets them in Common.

Parleying with Lludd

If the characters converse with Lludd, he offers to point them toward a place where they can find treasure in exchange for leaving him in peace. The behir keeps no hoard of his own. If they agree, Lludd directs them toward a "vast treasure" in the rolling gallery (x).

During the conversation, Lludd sizes up the party. If the characters appear wounded or offend the behir, he seizes his chance and unleashes his breath on them.

Treasure

Inside Lludd's stomach is a Periapt of Proof against Poison left over from an unlucky explorer the behir digested.

G4: Rolling Gallery

The rolling boulders are three galeb duhr, created and bound by Iggwilv to defend this cave. The elementals attack any intruders.

Treasure

A scattering of treasure glints in the bottom of the cave: 60 pp, 285 gp, 87 sp, three rubies worth 300 gp each, and a +1 War Pick.

G5: Tilted Cavern

Two umber hulks burrowed through this area recently. Though their tunnels collapsed behind them, the creatures lurk just beyond the alcove. If the irritable umber hulks detect the characters, the monsters burst through the rubble and attack.

Slippery Floor

The dripping water renders the uneven floor slick with mud and slime. A creature that moves faster than half its speed along the floor must succeed on a DC 15 Dexterity saving throw or have the prone condition. The umber hulks ignore this effect.

Tunnel

If the characters excavate the entrance to the tunnel through which the umber hulks entered this cavern, they find it runs down and away for 100 feet. It then angles upward and continues for 1 mile, exiting through the north side of the mountain.

G6: Small Gallery

The three giant lizards pose no threat to the characters. As they graze, the lizards nervously eye anyone who approaches them and keep their distance.

If a character casts the Speak with Animals spell or uses other means to communicate with the lizards, the reptiles explain one of their siblings was recently slain by a terrible, red-furred creature from a large cave to the west (see x). If the characters avenge the lizards' fallen kin, one of the lizards agrees to serve the party as a cavern guide and mount for the next hour.

[image: A barlgura leers atop a pillar infused with Abyssal energy]

Mushrooms

The fungi in this cavern are edible, and characters can forage food here without having to make an ability check.

G7: Smooth Cavern

Two gas spores grow in this cavern, one tucked among the boulders near the sinkhole and the other in the hole itself. When a creature comes within 30 feet of either spore, both spores attack.

Sinkhole

The sinkhole drops 75 feet down to a tunnel that runs 35 feet to the east, then drops another 100 feet to an underground stream. What lies beyond the stream is outside the scope of this adventure.

G8: Cavern of Stalagmites

Four barlguras lair in this dimly lit cave. Each demon perches on one of the pillars, waiting to ambush unsuspecting entrants. When combat begins in this area, the pillars activate.

Demon Pillars

Iggwilv conducted demonic experiments on the pillars in this cavern. Each round on initiative count 20 (losing initiative ties), the pillars pulse with Abyssal energy. When this occurs, non-Fiends within 10 feet of one or more pillars must succeed on a DC 15 Constitution saving throw or be warped by planar magic. Roll on the Abyssal Energy table to determine the effect, which lasts until the pillars pulse again or are destroyed.

Abyssal Energy

d4Abyssal Manifestation
1The target's limbs become rubbery and unreliable. It has disadvantage on attack rolls with weapons.
2The target's eyes squirm out of its head as worms; the target has the blinded condition.
3The target's feet become heavy, fluid-filled sacs, reducing its walking speed by 10 feet.
4The target's mouth vanishes, preventing it from speaking or casting spells with verbal components.

Destroying the Pillars

Each of the pillars has Armor Class 17, 50 hit points, immunity to poison and psychic damage, and vulnerability to radiant damage. Destroying the pillars prevents them from emitting Abyssal energy. A Hallow spell cleanses the pillars, accomplishing the same feat.

G9: Glowing Grotto

This dimly lit cave is a planar nexus through which Iggwilv once explored the multiverse. Fungi from the Feywild and crystals harvested from the deepest reaches of the Astral Plane fuel the cave's glow and anchor the planar magic that lingers here.

Planar Displacement

When a creature enters the grotto, a flare of magic teleports the entrant and creatures within 10 feet of it to one of the Outer Planes. Roll on the Grotto Destination table to determine where the creatures are sent. For the next minute, any creature that enters the grotto is transported to the same destination. Due to their planar nature, these areas don't appear on map 6.3.

The following sections detail these locations and how creatures transported to them can return to the Lost Caverns. Once a creature has been transported to a location in this way, it can't be sent to that destination by entering the grotto for 24 hours.

Grotto Destination

d4Destination
1Abyssal labyrinth (x)
2Elysian canyon (x)
3Infernal hall (x)
4Mechanized checkpoint (x)

G9a: Abyssal Labyrinth

This immense labyrinth is part of the Endless Maze—a layer of the Abyss ruled by the bloodthirsty demon lord Baphomet. The labyrinth fills a region of the Abyss roughly 1 mile on each side. The labyrinth's tunnels are 20 feet wide, 50 feet high, marred with scratches, and stained with blood.

The characters arrive in the presence of two minotaurs, each accompanied by a gorgon. Servants of Baphomet, the minotaurs seek to offer up the characters' heads as gifts to the demon lord. The gorgons obey the minotaurs' spoken commands.

Escaping the Labyrinth

When the characters negotiate the labyrinth, have them choose a navigator and their pace (fast, normal, or slow). It takes 1 hour to navigate the maze at a fast pace, 2 hours at a normal pace, or 3 hours at a slow pace. Halfway through the journey, the navigator must make a DC 16 Wisdom (Survival) check. If the characters are moving at a fast pace, the navigator makes the check with disadvantage, while a slow pace allows them to make the check with advantage. On a successful check, the characters find their way out. On a failed check, the characters must restart the labyrinth.

The longer the characters take to navigate the maze, the greater the risk of encountering the creatures within it. Every 30 minutes the party spends in the maze, roll on the Labyrinth Encounters table to see what, if anything, the characters meet.

The labyrinth's exit is a one-way portal at the end of a clean, misty tunnel. Creatures that pass through the portal emerge in front of x of the Lost Caverns.

Labyrinth Encounters

d20Encounter
1–10No encounter
11–12A row of humanoid heads on pikes
13–14A bloodthirsty hill giant with crooked horns
15–16An enormous, rampaging giant bull (use the mammoth stat block)
17–181d6 minotaurs
19–20An aspect of the demon lord Baphomet (use the goristro stat block)

Treasure

Near the labyrinth's exit, a desiccated, severed hand clutches a +2 Greataxe.

G9b: Elysian Canyon

This box canyon on the plane of Elysium tests the compassion and resolve of those trapped within. Six centaurs who speak Common were exploring the canyon when its walls collapsed, stranding them here. Unable to scale the sheer, 60-foot-high walls, the centaurs are out of ideas. The centaurs are friendly toward the characters unless attacked.

Shaydun, the centaurs' leader, approaches the characters. She doesn't know how the characters arrived in the canyon, but she's willing to help them find a way back to the Lost Caverns if they help the centaurs escape the canyon.

Escaping the Canyon

The characters can escape the canyon by the following means:

  • Clearing the Rubble. A character who inspects the rubble and succeeds on a DC 15 Intelligence (Investigation) check notices a protruding boulder that, if dislodged, could open a way through to the canyon beyond. A character can knock the boulder loose with a successful DC 25 Strength (Athletics) check. If the characters fasten ropes to the boulder, the centaurs offer to help haul it down for them (no check required). Freeing the boulder clears a path through the rubble.
  • Climbing Out. Scaling the canyon's walls without climbing gear or magic requires a successful DC 20 Strength (Athletics) check. The centaurs can't manage this climb. At the top of the canyon is a golden-barked oak tree the characters can use as an anchor for rope or other climbing equipment.

At your discretion, other means of exiting the canyon might exist. Either way, once the characters have freed themselves, they can easily help the centaurs do the same.

Treasure

Shaydun wears a magic necklace adorned with a small silver horseshoe. The necklace allows the creature wearing it to cast the Plane Shift spell once, after which the necklace loses its magic.

In exchange for helping the centaurs escape the canyon, Shaydun gifts the characters her necklace. If a character uses the necklace to return to the Lost Caverns, they do so unerringly, appearing in front of x.

G9c: Infernal Hall

This infernal hall is located within an abandoned courthouse on Phlegethos, the fourth layer of the Nine Hells. The hall is 60 feet wide and has 30-foot-high ceilings, but it is infinitely long and unbearably hot. The hall constitutes an area of extreme heat (see the Dungeon Master's Guide).

When the characters arrive, each of them is trapped in one of the pentacles (detailed below).

Devil Columns

The figures carved into the columns represent Belial and Fierna, joint rulers of the fourth layer of the Nine Hells. A character who succeeds on a DC 20 Intelligence (Religion) check recognizes the archdevils and the plane on which the hall resides. A character can climb the columns without having to make an ability check.

Mirror Ceiling

A character who looks up at the ceiling sees the floor of the glowing grotto (x) reflected in its surface. A character who studies the ceiling and succeeds on a DC 16 Wisdom (Perception) check notices faint ripples in its surface, like that of a pool.

Pentacles

A 10-foot-diameter, 20-foot-tall cylinder of magical force surrounds each pentacle, confining a creature within its bounds. Skeletons of creatures that never escaped the magical prisons dot the pentacles along the infinite hall. Fortunately for the characters, Iggwilv built a fail-safe into the pentacles when she created them ages ago in case her enemies ever tried to use them against her.

A Levitate spell allows a creature imprisoned in one of the pentacles to rise through the prison's area of effect and up to the ceiling. This exception doesn't apply to other forms of flight, such as the Fly spell or wings.

A character who examines the pentacle beneath them and succeeds on a DC 15 Intelligence (Investigation) check notices smudges along the metal, suggesting someone traced the shape in the past. If the character traces the shape of the pentacle imprisoning them, they gain the effects of a Levitate spell for 1 minute, with no concentration required.

Escaping the Hall

To escape the hall, the characters must overcome their magical prisons. They can escape the pentacles through the following means:

  • Dispelling the Circle. A successful Dispel Magic spell (DC 15) cast on the pentacle suppresses its magic for 1 hour, freeing the creature inside.
  • Levitation. A Levitate spell allows a character to rise out of the pentacle's area of effect.
  • Teleportation. A character who first succeeds on a DC 15 Charisma saving throw can then teleport outside the circle as normal. On a failed save, the attempt is wasted.

A creature that ascends to the ceiling is transported to the Lost Caverns in front of x.

Treasure

Propped against a column near one of the pentacles is a Weapon of Warning (glaive) veined with hellfire.

G9d: Mechanized Checkpoint

This checkpoint is located on Mechanus, a plane of absolute order. The three automatons (lawful neutral helmed horrors) attack the characters, who are unauthorized visitors. On initiative count 20 of the next round (losing initiative ties), up to three more automatons (lawful neutral suits of animated armor) emerge from the wall to replace any that were slain. These reinforcements continue to appear until the characters leave the area or die trying.

Escaping the Checkpoint

When an automaton is destroyed, its armored body crumbles to the floor as individual components. This includes its intact helmet, whose interior glows with a similar copper light to the flare that deposited the characters here. A character who dons the helmet is transported back to the Lost Caverns in front of x. The helmet then crumbles to dust.

G10: Jagged Cavern

Iggwilv once conjured demons and bound them to her service in this soaring cavern. Before she vanished, the Witch Queen left a deadly trap for anyone coveting her knowledge.

False Demonomicon

The book on the altar looks like the Demonomicon of Iggwilv, the preeminent treatise on the Abyss and demons. A character unfamiliar with the book can identify it with a successful DC 20 Intelligence (Arcana) check. However, the book on the altar is a trap: a fake tome containing an unstable seed of Abyssal energy.

If the book is moved or touched, it flips open, and its pages shuffle as if disturbed by a phantom wind. A coruscating, 5-foot-wide, 10-foot-tall slash of red energy tears through the air above the pages, revealing a marred Abyssal landscape beyond.

Two chasmes buzz out from the rift and attack. At the end of each round, roll a d20. On a 10 or lower, another chasme wriggles through the portal.

[image: Within the Lost Caverns, Iggwilv penned her fabled treatise on demons. The tome disappeared when she did]

Closing the Portal

The portal remains open for 1 hour or until six demons emerge, whichever comes first. The portal can be closed early through any of the following means:

  • Closing the Book. A character within 5 feet of the altar can close the book as an action with a successful DC 25 Strength (Athletics) check.
  • Destroying the Book. The book has Armor Class 15, 50 hit points, resistance to cold and fire damage, and immunity to poison and psychic damage.
  • Dispelling the Book. A Dispel Magic spell cast on the book suppresses its magic for 1 hour.

Closing the portal doesn't return escaped chasmes to the Abyss.

Treasure

Amid the bones on the floor is a Cloak of Elvenkind.

G11: Cave of the Skull

The skull belonged to a wizard who challenged Iggwilv and lost badly. The garment nearby, however, is a motionless cloaker that ambushes any creature that approaches the coffer.

Treasure

The coffer is worth 750 gp. It contains ten cracked emeralds worth 100 gp each and a jar of Keoghtom's Ointment.

G12: Pillared Cavern

Two ropers lurk among the calcite columns at the cavern's south end. The monsters attack when they can each lash out at a victim with their tendrils.

G13: Rotting Fungus Cavern

The remains of rotting mushrooms litter this chamber. Three shambling mounds thrive amid the detritus. When the characters enter the cave, the creatures lurch out of the piles of filth and attack.

The stone giant in area G14 regularly tosses dead mushrooms in to feed the shambling mounds.

Treasure

Buried in the rotting mush is a collection of shiny objects the shambling mounds have gathered, including 340 gp, a Potion of Clairvoyance, and a silver scroll tube worth 125 gp containing a Spell Scroll of Cloudkill.

G14: Giant Lair

This is the lair of Zyzkathol, a chaotic evil stone giant who succumbed to the demonic energy that permeates the greater caverns. He's accompanied by two giant beetles (use the rhinoceros stat block). When at rest, the beetles resemble boulders, requiring a successful DC 18 Intelligence (Investigation) check to discern they're animate.

When he notices the characters, Zyzkathol barks a command and sets the beetles on them.

Treasure

Hidden in Zyzkathol's bedding is a sack sewn from a giant weasel pelt that contains 375 gp. The giant wears an ivory necklace worth 200 gp.

G15: Fungus Garden

The fungus here is a food source for many of the greater caverns' creatures, including eight shriekers that are currently feeding here. If the shriekers sound off, Zyzkathol and his giant beetles (see area G14) come to investigate.

G16: Lofty Cavern

An adult black dragon named Calumnus recently moved into this vast cavern, whose natural ceiling rises to a height of 60 feet. Calumnus is aggressive and territorial, attacking all who enter, but the dragon retreats if reduced to 50 hit points or fewer.

Treasure

The treasure near the west wall is the dragon's hoard. It includes 67 pp, 235 gp, 2,750 sp, assorted gems worth 700 gp, and an ivory case worth 300 gp containing a Wand of Magic Missiles.

G17: Sanctuary Cavern

An aura of purity suffuses this tranquil cave. The greater caverns' fouler denizens avoid this area, making it a safe place for the characters to rest.

Hallowed Rest

This haven was made long ago by one of Iggwilv's enemies. A permanent Hallow spell (save DC 17) blankets the cave, with the following extra effect: Fiends and Undead can't see inside the cavern. The Corrupted Region feature of the greater caverns (see the "x" section) doesn't extend to this area.

G18: Grotto of the Idol

This chamber is yet another trap devised to foil would-be plunderers. The demonic idol uses the stone golem stat block but is carved in the likeness of a nalfeshnee. While the idol remains motionless, it's indistinguishable from an ordinary statue.

When the characters enter the chamber, a Magic Mouth spell cast on the idol utters the following:

If the characters attempt to take any of the items or otherwise disturb the idol, the idol attacks.

Illusions

The treasure and weapons in this room are illusions. A character who studies the objects and succeeds on a DC 16 Intelligence (Investigation) check discerns the illusions for what they are.

Treasure

The only legitimate treasures in this grotto are the idol's two jacinth eyes, which are worth 250 gp each.

G19: Vestibules

Six nearly identical areas lead from the tunnels into Iggwilv's inner sanctum (x). When the characters approach one of the outer doors, read or paraphrase the following text:

Each set of doors is 10 feet wide and 20 feet tall. The script around the edges of the doors is a mixture of Abyssal writing and arcane sigils of Iggwilv's design. The bronze scrolls are inscribed with the following warning:

The doors are unlocked but immensely heavy. When the characters enter a vestibule for the first time, read or paraphrase the following text:

The first hall the characters enter also contains a framed painting of a narrow boat on turbulent seas. A pale, raven-haired woman stands at the tiller, smiling under a stormy night sky.

Teleportation Lock

As the characters proceed down the hall, the air tingles with harmless but unsettling magic. When a creature opens the ebony door at the end of the hall, golden light flashes as the room's occupants are teleported to another part of the caverns. The door then swings closed.

The characters must open each of the six ebony doors before they can enter x, though the doors don't have to be opened in any specific order. A character who opens a door and succeeds on a DC 15 Intelligence (Arcana) check discerns the nature of the lock and the number of doors that remain. The doors can't be bypassed through any other means. After all the doors have been opened at least once, their magic fades, allowing passage to the innermost chamber.

The Vestibule Destinations table summarizes the vestibules and where each room sends its occupants.

Vestibule Destinations

VestibuleDestination
G19aG20a
G19bG20b
G19cG20c
G19dG20d
G19eG20e
G19fG20f

G20: Vestibule Destinations

Characters who open the doors in the vestibules (see x) are teleported to these intersections.

G21: Inner Sphere

[image: Great iron doors mark the entrance to the Witch Queen's inner sanctum]

The woman on the dais is Drelnza, the vampire daughter of Iggwilv.

Tasked with guarding the Witch Queen's treasures, Drelnza slumbers in this sanctum until all six ebony doors have been opened, at which point she awakes and plays the part of a warrior imprisoned here by Iggwilv.

When the characters descend from the ledge or otherwise make themselves known, Drelnza yawns and passes a hand across her brow, making a show of waking from a long, magical sleep. She introduces herself and welcomes her "rescuers," inquiring about the outside world seemingly to get her bearings. Drelnza spins a riveting tale about facing the Witch Queen in battle before succumbing to her evil magic. During the conversation, Drelnza uses her Charm action to sway as many of the characters as possible before she strikes. Drelnza fights to the death.

Arcane Security

The inner sphere is cloaked by a permanent Mordenkainen's Private Sanctum spell. The spell can't be dispelled—the magic is woven into the construction of the sphere. Iggwilv delighted in using her old rival's signature spell against his efforts to spy on her and locate her treasures.

Hidden Coffin

The interior of the marble dais is hollow. Drelnza's coffin is hidden within. A character who searches the dais and succeeds on a DC 20 Intelligence (Investigation) check notices hair-thin gaps under the alabaster slab that forms the dais's lid.

The slab weighs 3,000 pounds. It has Armor Class 17, 50 hit points, and immunity to poison and psychic damage. A character can use an action to try to pry the slab from the dais, doing so with a successful DC 20 Strength (Athletics) check.

Revealing Light

Creatures and objects can't have the invisible condition while within the lantern's bright light.

Iggwilv's Hoard

In addition to Drelnza's sword, Heretic, the treasures on display in the sanctum include the following:

  • Six decorative wooden screens (1,000 gp each)
  • Two carpets (750 gp each)
  • Two inlaid stands (250 gp each)
  • Four porcelain vessels (500 gp each)
  • A crystal bowl (1,000 gp) filled with assorted gems worth 10,000 gp in total
  • A silver tripod brazier worth 300 gp
  • Daoud's Wondrous Lanthorn, which hangs from the ceiling. The golden chain it hangs from is worth 500 gp.

An additional collection of magic is hidden within the hollow dais. Arranged at the foot of Drelnza's coffin are several magical tomes, which at the DM's discretion might include any of the following books:

Additionally, Drelnza's coffin holds a small golden birdcage. The cage is a magical prison that functions as an Iron Flask. Unlike a typical Iron Flask, however, a creature trapped inside has the incapacitated condition but can perceive through the cage and converse with nearby creatures. The birdcage is filled with bracelets, rings, and necklaces made of platinum, diamonds, and rubies worth a total of 10,000 gp.

While impressive, the trove in this chamber is but a fraction of Iggwilv's untold wealth. The rest has been spirited away; the search for her other treasures could drive a larger campaign beyond the scope of this adventure.

Conclusion

After the characters defeat Drelnza and claim their share of Iggwilv's lost treasures, they can rest safely in the inner sphere if they wish. The cavern's inhabitants don't dare breach the Witch Queen's former sanctum. Backtracking to the surface is a relatively simple task.

When the characters return to the margrave's agent at the Lazy Bat, Bannik can scarcely believe it. The characters are invited to return to the margrave's estate, where they receive a heroes' welcome and a banquet in their honor. High-ranking figures from Bissel and dignitaries from neighboring lands delight at the opportunity to meet the adventurers, hear their tales, and persuade them to part with some of their newfound wealth.

If the characters fail to secure Daoud's Wondrous Lanthorn for the margrave or otherwise refuse to deliver the lantern, he still throws them a warm reception but secretly sends agents to recover the item after the characters depart.

[image: Iggwilv's greatest treasure—her daughter, the vampire Drelnza—defends what remains of the archmage's hoard]