What Dwells Here?
A tribe of goblins has claimed many rooms on this level and erected a bazaar. These goblins oppose the Xanathar Guild and its beholder overlord. The rest of the dungeon is infested with sentient magical experiments and leftovers from the days when Halaster's apprentices used this level as a laboratory. Adventurers might also encounter a troublesome drow, a wererat gang, and members of a doomed adventuring party.Goblins
The Rustbone tribe of goblins has claimed an old throne room (area 1) and turned it into a bazaar. The Xanathar Guild wants to shut down the market before it attracts too many surface dwellers, while the goblins fight to keep it open. Admission into the goblin bazaar is free, but non-goblinoids are closely watched.Xanathar Guild
The Xanathar Guild aims to secure this level, plunder it thoroughly, and return valuable items to Skullport to be sold, thus boosting the town's sagging economy. There are two Xanathar Guild watch posts on the level, and each one has a leader: a drow named Shunn "Spider Eyes" Shurreth commands the northern watch post at area 9, and a human berserker named Nadia the Unbent leads the southern watch post at area 20. Wererats recently stole a stone key from the southern outpost. Shunn believes that the key unlocks something important (though he doesn't know what that might be) and wants to reclaim it. He intends to capture a wererat and ransom it for the safe return of the key. He offers 50 dragons to anyone who brings him a wererat captive or the location of the wererats' hideout (area 14).Drow and Wererat Gang
A drow mage in league with the Zhentarim has set up a hidden base on this level (area 14). The drow, Rizzeryl, has eight wererats in his employ. The Xanathar Guild is aware of the wererats, but not their drow master. Rizzeryl has the stone key that the wererats stole from the Xanathar Guild. He thinks it might unlock a Melairkyn vault hidden somewhere on this level, but he's wrong. In fact, the key opens a magic gate that connects levels 6 and 8 of Undermountain. The drow will give up this key in exchange for his life or the destruction of the Xanathar Guild outposts on this level.Fine Fellows of Daggerford
Anyone who explores this level might encounter three members of the Fine Fellows of Daggerford, an evil adventuring party. If Halleth the revenant (see level 1, area 37) accompanies adventurers, he uses his Vengeful Tracker trait to lead the party to his former companions so he can repay them for their betrayal. These three "Fine Fellows" are:- Copper Stormforge, a dwarven thief, values gold above all. He has been captured by goblins and imprisoned in area 1e.
- Midna Tauberth, a human priest of Shar, thinks she can do everything herself. The perils of this level have forced her to take refuge in area 11b.
- Rex the Hammer, a human warrior, seeks fortune and glory, and doesn't care whom he steps on to achieve it. Adventures can find him at the mercy of the mezzoloth in area 13g.
Mutated Apprentices
Halaster handed over this level to his fervent pupils, almost all of whom were driven mad by their studies and mutated by the magic they wrought, becoming gibbering mouthers and nothics. A mezzoloth summoned from the Lower Planes to serve as a wizard's assistant now rules over them all.Wandering Monsters
Monsters wander this level of Undermountain in search of food or treasure. Such monsters include carrion crawlers, mephits, and owlbears. If adventurers take a long rest on this level or pass through here after it has been cleared, there is a 50% chance that they will face an encounter on the table below.| d8 | Encounter |
|---|---|
| 1 | Three Carrion Crawlers |
| 2 | 1d6 + 5 Dust Mephits |
| 3 | 1d6 + 5 Ice Mephits |
| 4 | 1d6 + 5 Magma Mephits |
| 5 | 1d8 + 9 Mud Mephits |
| 6 | 1d8 + 9 Smoke Mephits |
| 7 | 1d8 + 9 Steam Mephits |
| 8 | Two Owlbears |
Exploring This Level
1. Goblin Bazaar
In this monstrous market live forty goblins. Half of them are guards, and the other half are traders. The goblin boss and his entourage lurk in area 1e.1a. Bazaar Side Entrance
Trash and debris litter the floor. The walls are adorned with carvings that once depicted dwarves carrying supplies. The dwarves' faces have been chipped away and replaced with cartoonish goblin heads drawn in charcoal. Banging noises can be heard to the north (the goblins in area 1b are building a wooden stage there).1b. Auction Hall
The goblins are erecting a stage against the north wall of this 20-foot-high chamber using wood stolen from elsewhere in Undermountain. Once the stage is complete, the goblins plan to auction slaves and other valuable merchandise here. The stage will be quite large when it's finished but is still in the preliminary stages of assembly. A pile of wrecked wooden furniture lies in the area's northwest corner. Seven goblins are here. Three of them are using stone hammers to pound rusty nails through decrepit wooden planks. The other four are clustered in the middle of the room, passing around a scroll on which someone has drawn a crude blueprint of a stage. If attacked, these goblins retreat to area 1d. They otherwise pay no attention to strangers. The goblins carry a total of 27 nibs and 15 shards.1c. Gibbets and Gravy
Four iron cages hang from chains hooked to the 10-foot-high ceiling. The cages are empty except for one that holds a wailing goblin named Glom. Glom was caught stealing food intended for the goblin boss, Yek. She hasn't eaten in two days and happily provides information or her service as a guide in exchange for food or freedom. She knows where the goblin boss keeps the rest of his treasure (area 1f). Glom knows the general layout of this level of Undermountain, the positions of the Xanathar Guild outposts, and the location of the stairs leading down to level 3. Glom eagerly betrays her liberators if someone with more food and the promise of a better life comes along. The lock on Glom's cage can be picked with a successful DC 15 Dexterity (Thieves' Tools) check. It can also be broken off with a successful DC 20 Strength (Athletics) check or a solid weapon blow.1d. Market Hall
This room has a soaring, 60-foot-high ceiling supported by two rows of stone pillars. The middle of the chamber is taken up by eight vendor stalls. Twenty-two goblins are here, sixteen vendors (two per stall) and six guards who stand in pairs near the exits to areas 1e, 1f, and 8. A granite throne stands against the north wall atop a rectangular stone dais. The goblins buy goods at half the normal price and sell them at three times the normal price. Anyone who succeeds on a DC 12 Charisma (Intimidation or Persuasion) check can bargain a goblin down to half its asking price for an item. All together, the goblin vendors have 1d4 of each of following items:- Arrows (3 dragons)
- Backpack (6 dragons)
- Bedroll (3 dragons)
- Candle (3 nibs)
- Chain (15 dragons)
- Chest or Crate (15 dragons)
- Club (3 shards)
- Crowbar (6 dragons)
- Dagger (6 dragons)
- Flask or Tankard (6 nibs)
- Glass Bottle (6 dragons)
- Greatclub (6 shards)
- Hammer (3 dragons)
- Handaxe (15 dragons)
- Hempen Rope (3 dragons)
- Hide Armor (30 dragons)
- Hunting Trap (15 dragons)
- Iron Pot (6 dragons)
- Jug or Pitcher (6 nibs)
- Ladder (3 shards)
- Lantern (15 shards)
- Light Hammer (6 dragons)
- Longbow (150 dragons)
- Parchment (3 shards)
- Pickaxe (6 dragons)
- Piton (15 nibs)
- Pole (15 nibs)
- Pouch (15 shards)
- Quarterstaff (6 shards)
- Sack (3 nibs)
- Shortbow (75 dragons)
- Shovel (6 dragons)
- Tinderbox (15 shards)
- Torch (3 nibs)
- Traveler's Clothes (6 dragons)
- Waterskin (6 shards)
- Whip (6 dragons)
1e. Yek the Tall
Flickering torches in iron brackets light this room. Four bugbears stand in the room's corners. A larger goblin named Yek the Tall, a goblin boss, reclines on a mound of cushions at the north end of the room, eating an apple. Ten goblins (Yek's entourage) lie about on moldy cushions around him. Chained to the south wall is a male dwarf clad in leather armor who has been gagged. He has copper-orange hair, but his beard has been shaved off. The bugbears work for Yek because he pays them. A bugbear abandons Yek and returns home to Skullport (on level 3) if given a bribe of 5 dragons or more. If adventurers humble themselves before Yek and appeal to his vanity, they are treated fairly. If they attempt to steal from him or have harmed any of his underlings, Yek sentences them to death and orders his goblin entourage and the bugbears to attack. Yek joins the fray only in self-defense. The beardless dwarf is Copper Stormforge (NE shield dwarf scout), a member of the Fine Fellows of Daggerford adventuring party. His hatred for goblins increased tenfold when they chopped off his beard, and if he is set free, he tries to kill every one of them. Currently, however, he has no weapons. As a reward for setting him free, Copper gives his liberators what he claims is an authentic map of the Sargauth Level (level 3). Copper folded the map into a tiny package and tucked it between his butt cheeks to hide it from his captors. He doesn't realize the map is fake and utterly worthless. The goblins under Yek carry a total of 60 nibs and 25 shards. Each bugbear carries a large pouch that contains 15 dragons.1f. Yek's Treasure
This room contains a gruesome display featuring the stuffed corpses of a beholder and six goblins, all of them in battle poses and adorned with costume jewelry. Also in the room is an ivory dragonchess board on a low stone table and a hefty, iron-banded wooden chest with iron rings for handles. The ivory dragonchess board is worth 25 dragons, and the wooden chest is filled with 2,000 shards.2. Kalabash's Chambers
Kalabash was one of Halaster's apprentices, though not one of the original seven. He has been trapped in a pocket dimension for hundreds of years now and is completely insane. Adventurers might stumble across him as they explore his chambers.2a. Water Pump
In the center of this room is a rusted iron hand pump and a deep stone basin. This pump draws water from a spring between levels of the dungeon. Using an action to crank the pump draws 1d4 + 1 gallons of potable water into the stone basin.2b. Abandoned Laboratory
This room is filled with dusty tables and cauldrons. Its stone hearth is cold. Piled atop the tables are alchemical tools and equipment, all of it ancient to the point of being unusable. Disturbing the laboratory in any way alerts the specter in area 2c.2c. Wizard's Kitchen
This decrepit kitchen contains an oven range, a washing basin, a hearth bearing a covered cook pot, and shelves filled with pots, pans, and cooking tools. A specter hides in the covered cook pot, emerging if the lid is lifted or if the specter is disturbed by noises from area 2b. The specter can command four nearby pots and pans to do its bidding. On the specter's turn, each pot makes a single melee weapon attack (+3 to hit) and deals 1d8 + 1 bludgeoning damage on a hit, before clattering to the ground and becoming inanimate once more.2d. Kalabash's Bedroom
The door to this room bears a sign written in Common that reads, “Kalabash's Room. Do not enter unless your name is Halaster.” A dusty bed stands with its headboard against the north wall. At the foot of the bed rests a locked wooden chest. A desk in the southeast corner has stacks of musty old tomes atop it. An old rug woven with arcane symbols lies in the middle of the floor (beneath the rug, painted on the stone floor, is a 10-foot-diameter summoning circle that has been partially erased). The summoning circle hidden under the rug radiates an aura of abjuration magic under the scrutiny of a detect magic spell, but three of its activation glyphs have been erased. Anyone who examines the circle and succeeds on a DC 15 Intelligence (Arcana or Investigation) check can reconstruct the circle and, with blood or paint, reapply the missing glyphs in 1d10 minutes. If the circle is completed, it immediately summons Kalabash (CE male Calishite human high mage). Appearing in the middle of the circle, Kalabash attacks any creature he sees. He is intoxicated and suffers the effects of the poisoned condition until he sobers up or until the condition is ended with a lesser restoration spell or similar magic. Erasing part of the completed circle causes Kalabash to be whisked back to his pocket dimension. The only item of value Kalabash has is his spellbook, which contains all the spells he has prepared. He also carries around an empty wine flask. The wooden chest is of solid construction, and its steel lock is warded with a magic trap. Picking the lock requires a successful DC 15 Dexterity (Thieves' Tools) check. If that check does not succeed, or if anyone tries to break or smash the lock, the mechanism releases a small bolt of lightning that deals 3d6 lightning damage to the creature tampering with it (no saving throw). The chest is empty except for a note in Common that reads, “Retirement fund. Don't spend this on ale, Kalabash!” The desk has twenty old books on it. Each book is blank and can be sold for 10 dragons.3. Halaster Puppet
Both doors to this room are difficult to open because furniture inside has been piled against them. A successful DC 15 Strength (Athletics) check forces open either door. An animated, life-size puppet of Halaster Blackcloak is hard at work on an experiment. The puppet is made primarily of wood and canvas, with a shoddy gray cloak draped over its shoulders. Dozens of cloth eyes have been sewn into the cloak. The puppet looms over a stone table covered with dusty alchemical equipment and vials of various solid and liquid substances, but nothing valuable or dangerous. The puppet responds to any movement within 20 feet of it and threatens any creature that comes closer, shouting in Halaster's voice, “Terrible and painful magical death! Fireballs and lightning bolts! Begone!” It speaks and understands Common, but voices nothing but empty threats and a desire to continue its “work” undisturbed. If asked what it's working on, it shouts, “Magic!” and chuckles. Anyone who watches the puppet work and succeeds on a DC 10 Intelligence (Arcana) check ascertains that the puppet isn't doing anything other than mixing harmless substances while muttering jiberish. The puppet falls to pieces if attacked or if a successful dispel magic spell (DC 15) is cast on it. Hidden inside the puppet is a flask of alchemist's fire that shatters as the puppet falls to pieces, causing its remnants to catch fire. The breaking flask does no harm to nearby creatures. If the puppet is destroyed, Halaster's voice magically calls out, “Auugh! Now who will find the cure to filth fever?!” before trailing off into silence.4. Abandoned Camp
The Xanathar Guild had a base camp here, but it was forced to abandon the place after a run-in with the Fine Fellows of Daggerford. This room is strewn with rotten supplies and the remains of a fire pit. Three bugbear corpses and an intellect devourer's body are heaped in the northeast corner. Searching the corpses reveals a scrap of parchment with the following phrase written on it in Common: “As many as there are stars in the sky.” This is the passphrase to safely enter the Xanathar Guild outpost at area 9.5. Arch Gate to Level 4
This dusty room is hidden behind a secret door disguised to look like a plain section of wall. Embedded in the middle of the room's north wall is a stone arch, its frame engraved with images of falling coins. The arch's keystone has a tiny slot in it. This is one of Halaster's magic gates, and its rules are as follows:- Feeding a gold coin into the slot in the keystone causes the coin to disappear and the gate to open for 1 minute. Other coins placed in the slot disappear but don't open the gate.
- Adventurers must be 8th level or higher to pass through this gate. The first creature to pass through the gate triggers an elder rune.
- A creature that passes through the gate appears in area 11c on level 4, in the closest unoccupied space next to the identical gate located there.
6. Music of the Dead
The hallway leading to this chamber is filled with the haunting sound of a harpsichord playing. In the middle of the room is a piano made entirely of bones, with human, dwarf, ogre, and halfling finger bones for keys. somber music emanates from it. Carved into the north wall is a single measure of musical notes. They are faded and difficult to read. The bone piano has been enchanted to play on its own but stops when a living creature comes within 10 feet of it. A detect magic spell reveals an aura of conjuration magic around the piano and a smaller aura of necromancy magic emanating from something inside it. Anyone who has proficiency with a musical instrument can correctly play the displayed notes on the bone piano. Anyone else who tries to do so must make a DC 20 Intelligence (Performance) check. A successful check causes a decorative skull above the keys to fall away, revealing the treasure. On a failed check, the performer must make a DC 15 Constitution saving throw. If the saving throw fails, the performer takes 4d10 necrotic damage, and the flesh of its hands is eaten away, leaving bleached white (but functional) skeletal hands. Hidden inside the piano is a raise dead spell scroll. Correctly playing the musical notes opens a hidden compartment that contains the scroll. Smashing or breaking open the piano damages the scroll, rendering it useless.7. Shocking Discoveries
Several chambers where mining equipment and copper ore were once stored are now occupied by laboratories devoted to experiments in electricity and necromancy. Trenzia, one of Halaster's new apprentices, conducts her research here.7a. Trenzia's Workshop
This well-maintained workroom reeks of rotting flesh and ozone. Odd metal instruments designed for measuring electricity rest atop tables, along with several loose scraps of parchment with notes that include terms such as “rate of decay” and “accumulation of charge.” A thorough search of the room yields a scrap of paper that was once part of Trenzia's log. It reads, “Day 1: Halaster has granted me this abandoned copper mine in the Arcane Chambers. Finally, I have access to the components needed for my experiments.” Everything beyond that point is smudged and illegible.7b. Ghoul Barrels
Ten sealed wooden barrels covered in dust rest against the walls. Two are empty, two contain fist-sized chunks of copper ore (50 dragons worth of copper per barrel), and the remaining six each have one ghoul crammed inside. Disturbing any of these barrels causes all six ghouls to burst forth and attack. A hammock laden with blankets hangs from anchors in the north wall. A copper-plated door is set into the southeast corner. The copper-plated door is connected to the lightning grid in area 7c. Unless the creatures in area 7c have been destroyed, the door emits a soft hum when approached. A creature that touches the humming door must make a DC 10 Dexterity saving throw, taking 3d6 lightning damage on a failed save, or half as much damage on a successful one. A creature wearing metal armor has disadvantage on the saving throw. Tucked into the folds of the hammock is another page from Trenzia's log. The only legible text reads as follows: “Day 3. I no longer trust the other apprentices. What they see as mysticism I know to be science! I can't stand their incantations and their mutterings any longer. If any of them try to intrude on my laboratory again, they're in for a truly shocking surprise!”7c. Trenzia's Laboratory
Trenzia turned this laboratory into a giant lightning trap, sacrificing herself in its construction. The floor is plated with copper tiles. The metal-coated skull of a half-elf (Trenzia) floats around the room, giving off crackling sounds as it electrifies the floor with rays of lightning. A flesh golem stands in the middle of the room amid destroyed tables, shards of broken glass, and rusty mining equipment. A 5-foot-wide, 5-foot-high chute in the southeast corner curves downward, descending 20 feet to area 13a. The chute contains plenty of handholds and footholds, and no ability check is required to descend it. After she was driven mad by her scientific and necromantic experiments, Trenzia convinced Halaster to transform her into a flameskull. On each of its turns, the skull can use an action to electrify the copper-plated floor. The floor remains electrified until the start of the skull's next turn. While the floor is electrified, any creature that steps onto the copper tiles or starts its turn in contact with them takes 3d6 lightning damage. Instead of taking damage, the flesh golem regains 10 hit points whenever it starts its turn on the electrified floor. If the skull is destroyed and later rejuvenates (see the flameskull's Rejuvenation trait), it resumes electrifying the floor and defending the room, with or without the golem. The flesh golem has instructions to kill all intruders and never leave the room. It obeys these and the skull's other commands until it goes berserk. If the golem attacks Trenzia's skull in its berserk frenzy, the skull uses its next action to try to calm the golem. While attempting to calm the golem, the skull can't electrify the floor.7d. Mining Woes
Three ghasts hunker down behind the door leading into this room, waiting to attack. This room contains the remains of a mining operation. Pickaxes and hammers litter the floor, as do the gnawed bones, torn black robes, and rubber boots of a female half-elf wizard. Notably absent is the half-elf's skull. The bones and clothing belonged to Trenzia. Halaster fed her body to the ghasts.7e. Copper Vein
An exposed bit of stonework has a thick vein of copper ore running through it. A scrap of paper lies on the floor. The scrap of paper is another partial entry from Trenzia's log that reads, “Day 10. With lightning and copper wires, I created a pack of ghouls. Hal was not impressed. He says I'm not ready for Dweomercore and its arcane secrets. I'll show him. His flesh golem has given me an idea for a trap more devious than any Hal could devise. Lightning - is there anything it can't do?”8. Painting Cross Hall
Paintings on the walls of this four-way intersection depict shield dwarves at work. Magic causes the images to move. The dwarves roll and stack barrels, carve blocks of stone, drink from stone tankards, and so forth. As creatures make their way down each hall, the dwarves wave at them and occasionally wink. These animated paintings are harmless.9. Spider Eyes Watch Post
The Xanathar Guild claims this corner of the dungeon. Shunn Shurreth, a drow exile favored by the beholder crime lord, commands the forces stationed here.9a. Trapped Hall
Two bugbears stand guard at the east end of this long hall, where it narrows to a width of 10 feet. The northern wall conceals five poison dart traps, triggered by hidden pressure plates in the floor marked T on the map. The bugbears, Bolgus and Bulkar, disarm the poison dart traps when Xanathar Guild members approach. When unfamiliar creatures approach from the west, Bolgus shouts for them to halt and Bulkar asks, “How many eyes does Xanathar have?” The correct reply is, “As many as there are stars in the sky.” If anyone gives them the wrong passphrase, the bugbears invite them forward but don't disarm the traps. If adventurers approach from area 9b without a Xanathar Guild escort, the bugbears attack them. The five poison dart traps are embedded in the walls north of the pressure plates. Anyone who searches the hall for traps and succeeds on a DC 15 Wisdom (Perception) check spots the nearest pressure plate and the dart holes in the wall north of it. When more than 20 pounds of weight are placed on a pressure plate, four darts shoot from the north wall. Each dart makes a ranged attack (+8 to hit) against a random target above the pressure plate. On a hit, a dart deals 1d4 piercing damage, and the target must make a DC 15 Constitution saving throw, taking 3d6 poison damage on a failed save, or half as much damage on a successful one. Each trap can be triggered three times before its supply of darts is exhausted. A lever, concealed by a false section of stone near where the bugbears stand, arms and disarms the poison dart traps. Anyone who searches the area finds the false stone and lever with a successful DC 15 Wisdom (Perception) check.9b. Shunn's Gang
Battered oil lanterns rest atop toppled blocks of stone, illuminating this partially collapsed hall. Crates, barrels, and seven wooden cots line the walls. Seven Neutral Evil Xanathar Guild human thugs and their leader, Shunn “Spider Eyes” Shurreth, gather around a campfire in the middle of the hall. Two intellect devourers have taken residence in the skulls of two Xanathar Guild members. The creatures use their Detect Sentience trait to telepathically detect intelligent creatures approaching. Shunn and his thugs can't be surprised if the intellect devourers sense intruders approaching. If an intellect devourer's host is killed, it tries to find another. A drow priestess of Lolth placed a curse on Shunn and forced him into exile after he displeased her. The curse partially transformed him into a spider, giving him eight red arachnid eyes, a mouth full of fangs, and black bristles sprouting from his slender limbs. A remove curse or greater restoration spell restores Shunn's natural form, but Shunn doesn't want the curse lifted. His horrific appearance strikes fear into the hearts of his comrades-in-arms and has earned him favor with Xanathar. Shunn believes that returning to his normal form might weaken his influence over his gang and diminish his status in the Xanathar Guild. Shunn is a drow elite warrior, and while cursed with spider features, he can climb difficult surfaces, even across ceilings, without needing to make an ability check. Shunn moves and converses with an eerie grace and prefers diplomacy over violence when dealing with adventurers. If adventurers seem interested in a truce, Shunn offers them 50 dragons if they find the wererats that are troubling his gang and return the stone key that they stole. Shunn's gang found the stone key on this level of Undermountain and is still searching for the lock that it fits into. If he or his thugs are attacked, Shunn Shurreth calls for bugbear reinforcements from area 9d. Shunn's goal in any conflict is to capture his enemies and haul them to Skullport as trophies. Once there, the prisoners are brought to Skull Island and left to the tender mercies of Commander Sundeth. The barrels and crates here contain enough water and dry food to sustain a single person for 600 days or Shunn's gang for 30 days. The thugs carry a total of 14 dragons in coin. On a black cord around his neck, Shunn wears a silver key (5 dragons) that unlocks the silver-bound chest in area 9c.9c. Gang's Treasure
Stone racks spanning the walls contain barrels that are so rotted and old that they fall apart when handled (the ale and water once stored in them have long since evaporated). A large stone table in the middle of the room is draped with cobwebs. A silver-bound wooden chest rests atop it. The chest has a built-in lock that Shunn Shurreth's silver key opens. The lock can also be picked with a successful DC 15 Dexterity (Thieves' Tools) check. The chest contains 100 dragons, which Shunn uses to pay his gang.9d. Bugbear Barracks
Ten bugbears sleep on the dusty floor of this room. They investigate any commotion they hear in area 9b.10. Ooze Temple
These four rooms comprise a temple devoted to water and oozes. All doors leading to these rooms are decorated with symbols of water, and each door forms an airtight seal when shut.10a. Skull in the Cube
This 30-foot-high room is swept clean, with no trace of dust or debris. The walls are decorated with paintings depicting horrific cyclopean cities of black stone submerged beneath raging seas. A gelatinous cube is trapped in the room. The monster is situated in the northeast corner when adventurers first arrive. Floating in the center of it is a dwarven skull. Anyone who succeeds on a DC 15 Wisdom (Perception) check can tell that the skull is suspended in a gelatinous cube, not levitating.10b. Flooded Room
This laboratory, with a 20-foot-high ceiling, is completely filled with 24,000 cubic feet of salt water created by a spell gone awry. Opening the door causes the water to empty into area 10a. Creatures within 20 feet of the opened door are caught in the deluge and must make a DC 12 Strength saving throw. Any creature that fails the saving throw is knocked prone and takes 1d10 bludgeoning damage. Once the water is released, it fills both rooms to a depth of half an inch. Swept into area 10a with the water is the putrid, rotting corpse of a human wizard in green and purple robes. This is what remains of Salamanth, one of Halaster's more foolish apprentices. A search of the room reveals overturned tables, waterlogged books destroyed by saltwater, and a wand (the dead wizard's arcane focus).10c. Altar to Juiblex
In the middle of this 20-foot-high room is a limestone altar topped with a misshapen mound of gold that looks like it was poured on the altar in molten form and left there until it cooled and hardened (the mound of gold is an ochre jelly of unusual color trapped in magical stasis). Black mildew drips from lidless eyes and gaping mouths carved into the walls. The wall carvings represent the all-consuming demon lord Juiblex. Though ghastly, the depictions are harmless. Close examination of the altar reveals that it bears an inscription in Abyssal that reads, “A gift of flesh, willingly given, can feed our eternal hunger.” Anyone who inspects this “mound of gold” can ascertain its true nature with a successful DC 12 Intelligence (Nature) check. A detect magic spell reveals an aura of transmutation magic around the ochre jelly, suggesting the presence of the stasis field. The stasis field immobilizes the ooze but also renders it impervious to damage. This magic is dispelled when it comes into contact with flesh or is targeted by a successful dispel magic spell (DC 17). Freed from its stasis, the ochre jelly attacks.10d. Caved-In Room
This room has partially caved in, but someone has bored tunnels through the collapsed sections, granting access to dungeon hallways south and east of here. The floor is covered with dust and debris, but the room contains nothing of interest.11. Midna's Lair
An apprentice of Halaster's claimed this area as her own work space centuries ago, using her mastery of the unseen servant spell to create multiple invisible helpers. Even after her death, her unseen servants persisted, waiting for her to return. Midna Tauberth, one of the Fine Fellows of Daggerford, recently intruded upon this hall and is using it as a rest area.11a. Hall of Degeneration
The walls of this passage are painted with images of wizards succumbing to madness and being transformed into nothics. One particularly vivid image shows shafts of eerie green light exploding out of a spellbook and changing a wizard into a gibbering mouther.11b. Master of the Unseen
Flickering lights created by continual flame spells spills out of this room into the hall. Freestanding iron torch brackets in the four corners of the room have continual flame spells cast upon them. Midna Tauberth (NE female Tethyrian human priest) relaxes in one of several overstuffed chairs in the middle of the room, waited on by nine unseen servants as created by the unseen servant spell. Around her neck, she wears two holy symbols: one shaped like a gold coin (the symbol of Waukeen, god of trade), the other a black disk outlined in purple (the symbol of Shar, god of darkness and loss). Empty bookshelves and desks line the walls. Against the south wall stands a long banquet table bearing fresh foodstuffs on copper platters and copper flagons filled to the brim with wine. A portrait of a smiling Halaster hangs above the table. Each day at dawn, the platters and flagons on the table are mystically replenished with fresh food and wine, courtesy of Halaster's magic. The effect produces enough food and wine for twelve people. The magic persists as long as the table remains in this room and there is dishware capable of containing the bounty. Midna isn't interested in sharing her newfound lair with others. She advises adventurers to leave or face her wrath. If they act hostile towards her, in the interest of self-preservation, she apologizes for her rudeness and allows the newcomers to partake of the food and wine on the table. If Halleth the revenant (see level 1, area 37) is present, he tries to kill Midna and reclaim his holy symbol of Waukeen. Midna stole it from Halleth's corpse and attempts to flee from the revenant towards the surface. If Midna is slain and the holy symbol of Waukeen is returned to Halleth, the revenant's thirst for vengeance abates, and both it and the holy symbol turn to dust. The unseen servants obey Midna's commands because she reminds them of their creator. They follow Midna and can leave the room to fulfill her wishes. Midna has no way to distinguish one servant from another, meaning that when she utters a command, all the servants follow that command. She can't issue orders to a single servant without the others performing the same task. The smiling portrait of Halaster is 3 feet wide and 5 feet tall. It has no magical properties, but is worth 25 dragons, though it's awkward to transport.12. Dwarven Tools
These hallways are lined with crumbling stone tables and shelves upon which rest sturdy dwarven anvils, whetstones, tongs, hammers, chisels, and other tools. Embedded in the wall at the end of the westward hallway is an arch gate. Close inspection reveals the image of a dead tree carved into its keystone. The rules of this gate are as follows:- Touching the arch with a dead twig or branch causes the gate to open for 1 minute.
- Adventurers must be 8th level or higher to pass through this gate. The first creature to pass through the gate triggers an elder rune.
- A creature that passes through the gate appears in area 3b on level 5, in the closest unoccupied space next to the identical gate located there.
13. Mutated Apprentices
Once a dwarven mithral mine, this section of the dungeon is home to apprentices whose attempts to unlock the secrets of the Weave transformed them into gibbering mouthers and nothics.13a. Dumathoin's Altar
A gibbering mouther wanders the hall to the east, attacking other creatures on sight. Overturned mine carts and discarded mining equipment lay scattered across the floor. A red stone altar covered with small, dirty handprints stands in the northern alcove. The altar is a 3-foot-tall, 500-pound tapered block of dark red stone engraved with Dwarvish prayers to Dumathoin, the Keeper of Secrets under the Mountain. Greasy goblin handprints cover the altar, which any dwarf would consider a desecration. Anyone who takes the time to clean the altar gains the following magical boon: all secret doors are plainly visible to that creature for the next 24 hours. Anyone who willfully desecrates the altar and then cleans it doesn't gain this boon (dwarven gods are not very forgiving). Beneath one of the overturned mine carts are four chunks of mithral ore, each worth 25 dragons and weighing 10 pounds.13b. Wall of Rust and Bones
Bisecting this room is an 8-foot-high, 2-foot-thick wall of hobgoblin skeletons and rusty armor, with a 2-foot gap between the top of the wall and the ceiling. A Tiny creature can pass through narrow openings in the wall. Climbing over the wall requires a successful DC 12 Strength (Athletics) check. The wall can be easily broken apart or pushed down, but doing so creates a lot of clatter and summons the nothics from area 13e.13c-13d. Vacant Washrooms
Inside each of these rooms is a rusted water pump (inoperable), basins, and stone toilets separated by thin slate dividers.13e. "Nothic to See Here!"
An arcane lock spell has been cast on the western door. Rizzeryl the drow mage (see area 14) can pass through the portal. Other creatures must force the door open with a successful DC 25 Strength (Athletics) check. Four nothics lurk here. Low-lying stone shelves along the walls are stuffed with crumbling pairs of dwarven boots. Rusty dwarven helmets and dusty goggles with tattered leather straps hang on pegs above them. The nothics are insane and attack most creatures they encounter. They are easily and quickly cowed by displays of magic, however. Once they realize they're in the presence of one or more spellcasters, the nothics become slightly more cooperative. They know that several bipedal rat creatures are holed up on the other side of the western door, and that their master is a “purple-skinned elf wizard with red eyes and white hair.”13f. Gibbering Mine
The walls in this partially collapsed section of the dungeon are streaked with veins of copper. Three gibbering mouthers have gathered here and begin to jabber as other creatures approach. They fight until killed.13g. Strike it Rich
Adventurers hear sounds of battle as they traverse the hall leading to this 10-foot-high room, which has partially collapsed. The room is lit by a single lantern resting in the middle of the floor. Minecarts about the room contain glittering heaps of copper ore. A wounded warrior with 22 hit points remaining named Rex the Hammer (LE male Illuskan human champion) has been backed into the southeast corner by a vicious mezzoloth and two nothics. Three dead nothics (killed by Rex) lie on the floor near them. The mezzoloth was summoned and bound to Undermountain by Halaster. Its task is to prevent intruders from looting the dungeon. It uses telepathy to command the nothics, which serve it out of fear. Rex was the founder and leader of the evil adventuring party known as the Fine Fellows of Daggerford. Despite hearing rumors about the dangers of Undermountain, Rex assumed (based on the success of Durnan and other capable explorers) that the Fine Fellows would run roughshod over the monsters dwelling within. Boy, was he wrong. Like most villainous groups, the Fine Fellows lacked unity. Fed up with his companions' bickering, Rex struck off on his own. He was searching this room for loot when the mezzoloth and the nothics came in behind him, cutting off his escape. If adventurers come to his rescue, Rex expresses his gratitude before quaffing the potion of healing in his backpack]backpack. On the surface, he seems to be amiable, confident, and eager to discover Undermountain's secrets. He's happy to join the party for an equal share of any loot found. Once he's back at full health (or close to it), though, Rex sheds his civil veneer and tries to bully adventurers into following his orders, berating and threatening anyone who defies him. The bullying gets worse until Rex is forcibly ousted or the party dissolves. Rex's backpack lies next to one of the mine carts. It contains a silvered shortsword, a 30-foot-long coil of hempen rope, 2 days of rations, a flask of oil, a pouch containing 13 dragons, and a potion of healing. The oil lantern in the middle of the room belongs to Rex as well. The mine carts contain over a thousand chunks of copper ore, each weighing 10 pounds and worth 1 dragon. The carts are so old that their axles are bent and rusted, rendering them inoperable.14. Base de Résistance
These two chambers have been claimed by a drow mage named Rizzeryl, his summoned quasit minion, and eight wererats. At least for now, Rizzeryl and the wererats are staunch allies. Rizzeryl works for two groups: House Auvryndar, a low-ranking drow house from Menzoberranzan that is slowly and secretly consolidating its power in Undermountain, and the Zhentarim, which is trying to drive the Xanathar Guild out of Skullport. His ties to the Black Network make Rizzeryl an enemy of the Xanathar Guild, which currently controls Skullport and is trying to secure the uppermost levels of Undermountain. Rizzeryl has begun haranguing the Xanathar Guild forces on this level with the help of the wererat gang, which hails from Skullport. The drow wizard and the wererats have no quarrel with adventurers who leave them alone.14a. Rizzeryl's Hideout
The door to this room has a mural painted on the outside depicting a darkmantle descending on an unsuspecting dwarf who is admiring a gleaming gemstone. An arcane lock spell has been cast on the door. Rizzeryl and his wererat gang can pass through the door, while other creatures must force it open with magic or a successful DC 25 Strength (Athletics) check. Rizzeryl the drow mage sits on a chair in the southwest corner while resting in a trance. If he hears someone coming through the eastern door, he casts greater invisibility on himself. A wooden table in the center of the room bears a map made of loose stones arranged to form walls and doors. Rizzeryl likes to be invisible as he engages intruders in conversation, hoping to learn their intentions. Any noise here alerts the wererats in area 14b, who remain hidden until Rizzeryl calls for them. Rizzeryl offers adventurers a reward if they destroy both Xanathar Guild outposts on this level (areas 9 and 20) and return with the heads of both guild leaders, whose names, he tells them, are Nadia the Unbent and Shunn Shurreth. Rizzeryl doesn't reveal the nature of the reward, other than to say it will make exploration of Undermountain easier. If adventurers deliver the heads of Nadia and Shunn, Rizzeryl gives them a stone key hidden in this room. If adventurers attack him, Rizzeryl calls forth the wererats to defend him while he summons a quasit. If adventurers overcome these forces, Rizzeryl trades the stone key for his life. Rizzeryl knows the way to Skullport through level 3 and might share this information with friendly adventurers who have helped him. He refrains from divulging his allegiance to House Auvryndar. He will, however, reveal his allegiance to the Zhentarim if one or more adventurers identify themselves as members of that faction. If they need assistance, Rizzeryl urges such characters to seek out Bosskyn Gorrb, a tiefling member of the Black Network who operates in Skullport. Rizzeryl also informs them that servants of Xanathar will allow safe passage to anyone who openly brandishes Xanathar's symbol. Beneath Rizzeryl's chair is a loose floor tile that conceals a hidden compartment, which can be found with a successful DC 15 Wisdom (Perception) check. It contains three items: Rizzeryl's leather-bound spellbook (which holds the spells he has prepared, plus arcane lock and sending), a 12-inch-long stone key, a 12-inch-long driftwood wand with the symbol of Xanathar (a circle with ten equidistant spokes radiating outward from its circumference) carved at one end. Rizzeryl uses this nonmagical wand to slip past the guardian in area 20a and to move through Skullport unmolested. The stone key weighs 10 pounds and bears the following inscription in Dwarvish: “Meet me on the Lost Level. Find my twin in Slitherswamp.” A detect magic spell reveals an aura of conjuration magic around the key, which opens a magic gate that connects levels 6 and 8 of Undermountain (see level 6, area 34b, and level 8, area 3, for more information on each gate). Rizzeryl knows that levels 6 and 8 of Undermountain are called the Lost Level and Slitherswamp, respectively, but he hasn't explored either level. The wererats have carefully arranged the loose stones on the table to form an accurate map of this level of Undermountain; the map, however, omits the chambers hidden behind secret doors (areas 5, 20c, 20d, 22e, 22f, 25h, and 26b). There's no easy way to transport this map without knocking the stones out of alignment and rendering the map useless.14b. Wererat Barracks
Eight wererats in human form sleep on dirty cots in this room. They are loyal to the Zhentarim and determined to push the Xanathar Guild out of Skullport and Undermountain. The wererats are short, unkempt humans of mixed age with thin limbs, beady eyes, and nervous tics. They clad themselves in filthy, smelly, ill-fitting clothes. Their leader is a crass, middle-aged woman named Zilitsa Ilvarren. She is mean-spirited but has a good rapport with Rizzeryl, whose intelligence she admires. The others are a degenerate bunch of inbred, light-fearing weirdos who've spent too many years living underground. The men are named Frek, Henk, and Kozrik, and the women are Arreth, Elabbor, Kreena, and Sybilee. An unlocked wooden chest against the south wall holds 30 dragons, a copper tankard similar to those found in area 22a, a battered and tarnished silver scepter topped with a Dwarvish rune meaning “justice” (25 dragons), and a romance novel entitled Out of the Inferno (40 dragons).15. Dusty Throne
Much of this room collapsed long ago, and what remains is covered with dust. Footprints (left by wererats in human form) crisscross the dusty floor. A plain stone throne stands against the south wall. Beyond it, heaps of rubble fill a collapsed tunnel. A search of the throne and the surrounding room yields nothing of value. The wererats in area 14 have already searched the area thoroughly.16. Partially Collapsed Room
The back of this room has collapsed, filling the chamber with dust and debris. No one has been here in ages, and nothing of value remains.17. Hungry Rust Monsters
This old festival hall has an arched ceiling 30 feet high. Two rust monsters are fighting over a rusted steel helmet in the middle of this room, casting it about as they knock each other around. The walls are decorated with carvings of dwarves singing and drinking. A dozen empty iron torch brackets are mounted to the north and south walls at 10-foot intervals. The rust monsters can't find enough metal to satisfy their hunger. The helm provides a momentary distraction that creatures can use to cross the hall safely after they first arrive. The next time they come here, though, the rust monsters are waiting for them. The torch brackets bolted to the walls are beyond the rust monsters' reach but make irresistible snacks if fed to the creatures. Tearing loose a torch bracket requires an action and a successful DC 15 Strength (Athletics) check. One bracket is enough to distract the rust monsters for 1d6 minutes.18. Cold Storage
The Melairkyn dwarves used this chamber for cold storage. Halaster has turned it into a trap. The room is bitterly cold. The walls rise 10 feet, then angle inward, forming a pyramidal roof with a 40-foot-high apex. Inscribed on the sloped north wall is a 10-foot-tall Dwarvish rune that glows with a faint blue light. Any character who understands Dwarvish knows that the oversized rune on the north wall is an ancient symbol meaning “cold.” A detect magic spell reveals an aura of conjuration magic around the rune. The rune's magic lowers the room's temperature to 0 degrees Fahrenheit. When a spell is cast in this room (including one cast from a magic item), the giant rune flashes and deals 8d8 cold damage to all creatures in the room. Once the rune has released this cold energy, it can't do so again for 1 hour.19. Giant Spider Den
Giant spiders make their home here despite countless attempts by adventurers to get rid of them.19a. Arachnid Down
Narrow paths wind between scattered piles of broken furniture and garbage. Two iron chandeliers, once anchored to the 20-foot-high ceiling, have fallen - their ropes cut. One has crashed into a pile of debris. Pinned beneath the other chandelier is a dead giant spider.19b. Old Bedchamber
A dead giant spider, its body shot full of arrows and scorched by fire, lies next to a broken wooden bed against the east wall. Standing against the south wall is a wooden armoire draped in cobwebs. The armoire contains the skeletal remains of a halfling adventurer who was trapped inside by giant spiders and starved to death. The skeleton is clad in a chain shirt and wears a ring of swimming on one bony finger. Anyone who searchs the armoire also finds an explorer's pack (minus water and rations).19c. Sticky Webs
This room is full of thick, sticky webs. The webbing stretches all the way to areas 19d and 19e. These web-filled areas are difficult terrain. Moreover, a creature entering a webbed area for the first time on a turn or starting its turn there must succeed on a DC 12 Dexterity saving throw or become restrained by the webs. A restrained creature can use its action to try to escape, doing so with a successful DC 12 Strength (Athletics) or Dexterity (Acrobatics) check. Each 10-foot cube of giant webs has AC 10, 15 hit points, vulnerability to fire, and immunity to bludgeoning, piercing, and psychic damage. Any tugging or burning of the webs in this area alerts the giant spiders in area 19d, which creep down the hallway to investigate.19d. Spider Warren
Five giant spiders lair here and attack all intruders.19e. Spider Larder
Dense webbing fills this room as well. Suspended within the webs are six cocoons. Five contain the desiccated corpses of four goblins and a nothic. The sixth contains a swarm of spiders that bursts forth and attacks if the cocoon is torn open. The dead nothic has no treasure. A thorough search of the goblin corpses yields 20 nibs, 18 shards, 5 dragons, and a silvered dagger.20. Dead Eyes Watch Post
The Xanathar Guild forces stationed here include five human thugs, eight bugbears, and their leader, Nadia the Unbent. A beholder zombie provides added security.20a. Beholder Zombie
A beholder zombie floats near the 20-foot-high ceiling of this chamber, out of melee range. Painted in white around its central eye is a circle with ten equidistant spokes radiating outward from its circumference (Xanathar's symbol). Sounds of mock battle emanate from the tunnel to the west (leading to area 20b). The beholder zombie attacks anyone who enters the room without brandishing or wearing the symbol of Xanathar. Combat in this room brings reinforcements from area 20b.20b. Watch Post Barracks
Unless they are drawn to area 20a by sounds of combat, the following creatures are training here: a 7-foot-tall, powerfully built woman with shaggy black hair and pale skin named Nadia the Unbent (NE female Illuskan human berserker), five human thugs (three women and two men), and five bugbears. Painted in blood on the middle of the floor is a 10-foot-diameter circle with ten equidistant spokes extending outward from its circumference (Xanathar's symbol). Fifteen leather hammocks are hooked to stone brackets that protrude from the walls at regular intervals. A secret door in the west wall leads to area 20c. If she's here, Nadia the Unbent stands in the middle of the bloody circle, armed with a 10-foot pole, and is using it to knock about her underlings in a contest to see who, if anyone, can push her out of the circle. Nadia relishes any opportunity to fight and kill, and she hurls herself and her forces into battle without a second thought.20c. Arch Gate to Level 6
This hallway has three alcoves:- The two southernmost alcoves contain secret doors to areas 20b and 20d, respectively.
- The alcove to the north has an arch embedded in its back wall. Carved into the arch's keystone is an image of a rust monster.
- Touching the arch with a nonmagical item made entirely of metal (such as an iron spike) reduces the item to powdered rust and opens the gate for 1 minute.
- Adventurers must be 9th level or higher to pass through this gate. The first creature to pass through the gate triggers an elder rune.
- A creature that passes through the gate appears in area 24 on level 6, in the closest unoccupied space next to the identical gate located there.
20d. Secret Armory
This 20-foot-high room is hidden behind a secret door. Three bugbears have broken away from the main group in area 20b to search this room for treasure. They have worked their way to the east end of the room and aren't expecting trouble. Weapon and armor racks stand like library bookshelves in the middle of the room, with dusty, web-filled aisles between them. Half embedded in the floor in the middle of the room is a 1-foot-thick, 6-foot-diameter stone sharpening wheel. A stone pedal next to the wheel causes it to turn when stepped on. One of the bugbears is rummaging through a collection of dwarven morningstars and casting undesirable ones onto the floor. The other two are fighting over a rusty shield embossed with a symbol resembling a stylized goblin skull. The room contains dozens of suits of plate armor, scale mail, and chain mail, as well as scores of shields, battleaxes, morningstars, warhammers, war picks, and javelins. Most of these items have deteriorated to the point of being useless and irreparable. Rust has eaten away the metal, and dampness has rotted the leather straps and bindings on the shields and armor.21. Enchanted Ballistae
The arched, 30-foot-high ceiling of this long hall is studded with glowing red crystals that cast dim light throughout the hall (crystals pried out of their fixtures go dark). Parked in front of the door to area 22a are two ballistae. Each ballista has been magically enchanted to perceive and attack intruders coming down this hall within 120 feet of it. As an action, it can fire a magic bolt of fire (+6 to hit) at a target it can perceive, dealing 3d10 fire damage on a hit. Each ballista has an AC of 15, 50 hit points, and immunity to poison damage. It can't be blinded, charmed, deafened, frightened, paralyzed, petrified, or poisoned, and it can't right itself if knocked prone.22. Garrux's Brewery
This complex was built by a dwarf named Garrux, who served as Master of Ale and Provisions for the Melairkyn dwarves.22a. Ale Dispenser
A stone pillar in the middle of the room has a ring of six copper spigots jutting out of it, 3 feet above the floor. Carved into the walls are twenty carvings depicting drunken dwarves in different poses. One hand of each dwarf protrudes from the wall. Three of these hands grasp copper tankards. The stone pillar has copper pipes running through it. These pipes connect to the vats in area 22c. When the brewery was operational, dwarves could draw ale from the pillar into tankards to quench their thirst. There used to be twenty copper tankards secured to the wall carvings, but most of them have vanished over the years. Nothing happens if five of the six spigots are turned. Turning the sixth spigot causes a patch of green slime to pour out of it. The patch of green slime covers a 5-foot square, and can't be avoided as it pours out. A creature that comes into contact with green slime takes 1d10 acid damage. The creature takes the damage again at the start of each of its turns until the slime is scraped off or destroyed. Against wood or metal, green slime deals 2d10 acid damage each round, and any nonmagical wood or metal weapon or tool used to scrape off the slime is effectively destroyed. Sunlight, any effect that cures disease, and any effect that deals cold, fire, or radiant damage destroys a patch of green slime.22b. "Brewers Only!"
Nestled between areas 22a and 22c is a 10-foot-high, 10-foot-square room. A brass plaque bolted to the western door has the following words stamped into it in Dwarvish: “BREWERS ONLY! Others keep out! By order of Garrux, Master of Ale and Provisions.”22c. Ale Vats
Six stone vats, arranged in two rows of three, dominate this 20-foot-high room. A double door in the west wall has stacks of old barrels on both sides of it. The doors are painted with images of two dwarves in profile, facing each other while standing on sideways barrels. The Melairkyn dwarves stored ale in these vats. Each vat is a hollow, slightly bulging stone cylinder 10 feet high and 10 feet in diameter, with 6-inch-thick walls. A copper spigot is embedded in the vats on the side facing the nearest wall, at a height of 3 feet. A narrow stone staircase curls up the exterior of each vat to the top, which is fitted with a hinged copper lid. The vats' interiors are lined with copper and have a pipe at the bottom that runs under the floor to the ale dispenser in area 22a. Four of the vats are empty, their contents having long since evaporated or been depleted. The southwest vat contains a beholder zombie, which rises out of the vat and attacks if disturbed. There are thirty empty barrels, all made of iron-banded zurkhwood (a woody fungus). Most are in such poor condition that they can no longer hold liquids without leaking, but clever adventurers can use them to safely avoid the pit traps in area 22d.22d. Barrel Run
Beyond a 10-foot landing, this hall gradually slopes down toward the west. Secret doors at the west end of the hall open into areas 22e and 22f, respectively. Dwarves used to fill barrels of ale and roll them down this hall to be stored in the secret chambers. The Melairkyn dwarves built three 20-foot-deep pits in the sloped floor to guard their ale supplies. The pits' covers blend in with the surrounding floor, though a successful DC 15 Wisdom (Perception) check detects each pit. When a creature weighing 50 pounds or more steps on a pit's cover, it swings open like a trapdoor, causing the creature to spill into the pit below and take 2d6 bludgeoning damage from the fall. The lid is spring-loaded and snaps closed after the creature falls through. A successful DC 20 Strength check is necessary to pry the lid open. Anyone in the pit can also attempt to disable the spring mechanism from the inside with a successful DC 15 Dexterity (Thieves' Tools) check, provided that the mechanism can be reached and they can see in the dark. Wedging at least two iron spikes between the pit's lid and the surrounding floor prevents the lid from opening, thereby making it safe to cross. The lid can also be magically held shut with an arcane lock spell or similar magic. The dwarves constructed the pit covers so that they won't open if an object is rolled over them. Anyone can circumvent the traps by climbing into an empty barrel and rolling down the hall or climbing onto a barrel and balancing atop it as it rolls down the hall. Balancing atop a barrel as it careens down the hall requires a successful DC 20 Dexterity (Acrobatics) check.22e. North Ale Storage
This chamber is hidden behind a secret door. The room's walls climb 10 feet, then angle inward to form a pyramidal cap with a 30-foot-high apex. Stacked in the middle of the room are one hundred forty zurkhwood barrels banded in iron. The barrels form a 21-foot-high pyramid with a base measuring seven barrels on a side. Engraved on the lid of each barrel is a magical glyph that radiates an aura of abjuration magic under the scrutiny of a detect magic spell. Each barrel contains 40 gallons of dwarven ale that has been magically preserved for centuries. Removing a barrel's lid or breaking the barrel causes its glyph to fade away, ending the preservation spell on that barrel. If the ale is marketed as “Melairkyn Ale,” “Undermountain Ale,” or something similar, adventurers can sell a barrel of it for 40 dragons in Waterdeep. A full barrel of ale weighs approximately 400 pounds.22f. South Ale Storage
This room is identical to area 22e, except the pyramid of barrels has collapsed. Most of the barrels lie smashed on the floor. Fifty-nine of them remain intact, their ale preserved. Another three appear to be intact but are, in fact, three mimics placed here by Halaster. The three hide within 10 feet of one another and fight together.23. Ruined Dwarven Temple
These rooms once formed a temple dedicated to the dwarven god Dumathoin, the Keeper of Secrets under the Mountain, but Halaster has destroyed and replaced most of their original contents.23a. Defaced Dwarves
The walls climb 15 feet, then angle inward to create a peaked, 30-foot-high ceiling. The sloped upper walls have red glowing crystals set into them. These crystals fill the hall with dim light (crystals pried out of their fixtures go dark). The lower walls were once lined with carvings depicting dwarves pushing mine carts toward the west, but these works have been defaced and, in some cases, replaced with stony tentacles that protrude from the walls. A 20-foot-tall double door stands closed at the west end of the hall. Carved into the walls flanking the double door stand armored dwarves, their stony beards flowing out of great helms that conceal their facial features. Halaster used magic to distort the wall carvings almost beyond recognition and to create tentacle-like protrusions that weren't part of the original design. These tentacles writhe as creatures pass by them - a harmless effect created by the Mad Mage.23b. Hall of Dead Dragons
The 30-foot-high vaulted ceiling of this room is supported every 20 feet or so by thick stone arches. Standing in the hall are the skeletons of four adult dragons, their bones held together by wire and cement. A few pieces of each dragon have broken off and fallen to the floor. A fifth dragon skeleton in a similar state of disrepair fills an alcove to the south. This hall contains the posed, inanimate skeletons of five adult dragons - one each of brass, bronze, copper, gold, and silver. The gold dragon skeleton occupies the southern alcove, while the others are lined up in the main hall. The skeletons are harmless.24. Dead Adventurer
What was once a dwarven shrine is now the tomb of a long-dead adventurer. Splayed across a broken stone bench in the middle of the room are the skeletal remains of a tiefling clad in rotted leather armor. The skeleton clutches a quarterstaff that has become brittle with age. A tattered backpack contains adventuring gear that has rotted or rusted away. Casting a speak with dead spell on the skeleton reveals that the tiefling, Savir, was a monk who fell prey to a cloaker. Savir's spirit doesn't know what became of his adventuring companions or the cloaker. If questioned about Undermountain, Savir's spirit reveals that there's an elven tomb nearby with a secret door in the north wall that neither he nor his companions could open (the spirit is referring to area 26a but doesn't remember how to get there).25. Creature Storage
Halaster uses these chambers as a storage facility for creatures that he has captured and petrified. He restores them to flesh using the elven magic in area 25a.25a. Pillars of Restoration
Supporting the 20-foot-high ceiling are four pillars of white marble, each shaped in the likeness of a female elf in flowing robes with a flowering branch clutched to her chest. The pillars face inward. Circling the pillars counterclockwise is a quadrone with its bow at the ready. It makes clicking and clacking noises as it walks. The walls have carvings of unicorns and bare-branched trees. A detect magic spell reveals an aura of abjuration magic around the pillars. Touching a pillar while speaking the proper command phrase (“Elf magic!”) causes a pale light to fill the area between the four pillars, ending the following conditions on a creature in that area: blinded, deafened, petrified, poisoned, and stunned. This magical effect can be activated four times, once for each pillar touched. The pillars regain their magic at the next dawn. The pillars lose their magic if even one is destroyed or toppled. A pillar has AC 17, 90 hit points, and immunity to poison and psychic damage. It can be toppled with a successful DC 30 Strength (Athletics) check. Halaster found this rogue modron, decided to adopt it, and gave it a name: Halastron. The modron considers Halaster its friend and follows his orders to the best of its ability. Its orders are as follows:- Remember its name.
- Defend itself.
- Attack anything that tries to damage or topple the caryatids.
- Walk in a counterclockwise circle around the pillars when not defending itself or the pillars.
25b-25r. Lifelike Statues
Stored here are creatures that have been turned to stone by Halaster, as summarized in the table below. Each can be restored to flesh with a greater restoration spell or similar magic. A restored creature acts in accordance with its nature. For example, the grick in area 25b is likely to attack all other creatures out of hunger. When Halaster wants to restore a petrified creature to flesh, he uses a telekinesis spell to transport it to area 25a, then relies on the magic of the pillars there. Area 25h is hidden behind a secret door and contains a lifelike statue of Halaster. Casting a greater restoration spell on the statue or subjecting it to the magic of the pillars in area 25a triggers a magic mouth spell cast on the statue that says, “Fools!” Area 25r has a statue petrified wererat that looks like a statue of a wiry young man grasping a shortsword. This wererat is not part of Rizzeryl's gang (see area 14) but tries to join it if given the chance. His name is Zarn Kassifax.| Area | Creature(s) |
|---|---|
| 25b | Four Bullywugs |
| 25c | Three Gricks |
| 25d | Two Drow |
| 25e | Four Rust Monsters |
| 25f | Five Troglodytes |
| 25g | Six Goats |
| 25i | A Boar |
| 25j | A Constrictor Snake |
| 25k | A Kenku |
| 25l | A Lizardfolk |
| 25m | A Mind Flayer |
| 25n | A Nothic |
| 25o | A Orc War Chief |
| 25p | A Giant Badger |
| 25q | A Quaggoth |
| 25r | A Wererat |
26. Ancient Elven Tomb
These chambers are much older than the dwarf-hewn chambers that surround them, as evidenced by the crumbling walls, the slanted floors, and the thin streams of dust pouring down through cracks in the sagging ceiling. Halaster converted this tomb for the elven dead into a series of test chambers that now lie abandoned.26a. Do Not Feed the Owlbears!
Two owlbears left here by Halaster are hungry and attack anything that enters this room. A dozen elven sarcophagi arranged about this dusty room have been reduced to rubble. Time and neglect have all but destroyed wall carvings that depict elves mounted on elk, parading through a forest as the seasons change around them. A secret door in the north wall leads to area 26b.26b. Secret Tomb
In the middle of the dusty tomb rests a 7,500-pound alabaster sarcophagus atop a 1-foot-high block of granite. The lid of the sarcophagus is carved in the likeness of a regal elf of indeterminate age and gender, with a yawning cat stretching on the elf's chest. The cat is part of the lid's carving, not a separate sculpture. Anyone who inspects the sarcophagus closely and succeeds on a DC 17 Wisdom (Perception) check realizes that it's a solid block of alabaster with a fake lid carved to appear openable - a false tomb built to confound would-be treasure-hunters.26c. Halaster's Crushing Eye
Three stone tables lie strewn about the room, surrounded by ceramic shards that were once funerary urns (the owlbears in area 26a are responsible for the destruction). A 10-foot-wide, 10-foot-high hallway to the south slopes gently upward to area 26d and contains a rolling sphere trap. The 10-foot-square section of floor marked X on the map is a pressure plate. When 20 or more pounds of pressure depress this plate, a 10-foot-diameter stone sphere painted to look like a bloodshot eyeball careens from an alcove at the top of the sloped hallway and down the passage toward area 26c. With a successful DC 20 Wisdom (Perception) check, anyone searching the hall for traps can spot the pressure plate. Wedging four or more iron spikes or similar objects under the pressure plate prevents the trap from activating. When the sphere is released, all creatures present roll initiative, and the sphere rolls initiative with a +8 bonus. On its turn, it moves 60 feet in a straight line until it reaches a corner, then changes direction to follow the sloped tunnel until it comes to rest in area 26c. The sphere can move through other creatures' spaces, and creatures can move through its space, treating it as difficult terrain. Whenever the sphere enters a creature's space or a creature enters its space while the sphere is rolling, that creature must succeed on a DC 15 Dexterity saving throw or take 10d10 bludgeoning damage and be knocked prone. A creature within 5 feet of the sphere can attempt to slow it down by using an action to make a DC 20 Strength check. On a successful check, the sphere's speed is reduced by 15 feet. In the sloped hallway, this reduction lasts only until the end of the sphere's next turn. If the sphere's speed drops to 0 on a flat surface, it stops moving and is no longer a threat.26d. Bloodletting Chamber
This 10-foot-high room holds a row of six slanted stone tables intended for ritualistic bloodletting. Each table is fitted with rusty shackles and leather straps. Under the lower end of each table, set into the floor, is a shallow, circular stone basin for collecting blood.26e. Abandoned Study
The lid of a stone sarcophagus rests atop two misshapen blocks of stone, creating a makeshift desk at the south end of the room. Behind it is a high-backed chair made of charred wood that has one armrest missing. Beyond the desk and chair, dusty books are crammed into alcoves in the south wall. Similar alcoves in the other walls contain tall, alabaster funerary urns covered with dust and cobwebs (seventeen in all). The alabaster urns are cracked, chipped, and worthless. They contain nothing but dust - for the most part. Buried in the dust inside one of the urns is a tiny white pouch containing dust of disappearance. There are 7 mundane books in total, including:- A guidebook entitled Astonishing Journey in the Jungle (20 dragons)
- A fiction book entitled Aldir's Memory (20 dragons)
- A biography entitled Uncovered Treatise of the Cleric (10 dragons)
- A biography entitled Great Existence of the Captain (1 dragon)
- A religious doctrine entitled Conclusive Revelations of the Dwarves (6 dragons)
- A guidebook entitled Mysterious Tracts of the Wasteland (20 dragons)
- A fiction book entitled Colors of Flowers (10 dragons)
Aftermath
If they're weakened but not eradicated, the goblins begin constructing traps around the perimeter of their market to better protect themselves against aggressive adventurers and bad neighbors. They favor collapsing roofs, falling nets, and poison darts. The goblins also train and deploy giant rats, using them as watchdogs. Some of these might be Rizzeryl's wererats in rat form, sent to infiltrate the goblin lair and spy on adventurers who find their way to the goblin bazaar. Destroying the two Xanathar Guild outposts allows the goblins to expand their territory. Unless the goblins are also wiped out, goblin patrols become more common throughout this level of the dungeon.
Type
Dungeon
Parent Location
Connected Rooms
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