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The Handy Haversack

Level 6: Lost Level

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The Lost Level is designed for four 9th-level characters, and characters who defeat the monsters on this level should gain enough XP to advance halfway to 10th level. This level was a temple complex dedicated to the dwarven god Dumathoin, the Keeper of Secrets under the Mountain. Hidden inside is the tomb of Melair, king of the Melairkyn dwarves.

Before running this level, review the “Duergar” entry in the Monster Manual. That information will help you run and roleplay the duergar NPCs found throughout the Lost Level.

What Dwells Here?

Until recently, the Lost Level was physically cut off from the rest of Undermountain. But when umber hulks burrowing through the mountain stumbled upon it, they left tunnels in their wake for treasure hunters to follow.

Raiders of Clan Ironeye

The duergar of Clan Ironeye, led by a half-shield dwarf, half-duergar prospector named Skella Ironeye, have come to plunder this level of Undermountain. They are assisted in this effort by two cloakers from the conclave on level 5, which hope to turn this level into a hunting ground. After gaining entry through an umber hulk tunnel that leads down from level 5, the raiders managed to loot several rooms. But a combination of traps and unexpected monsters has diminished their numbers and dimmed their enthusiasm.

Skella is obsessed by artistry and beauty, in stark contrast to the usual duergar focus on utility. The duergar she leads are content to follow her for the sake of what their raids will earn them, and they care nothing for the historical value of the relics they steal and destroy. Skella is willing to parley with adventurers and stay out of their way in exchange for a chance to plunder more of the dungeon and leave in one piece. Her lawful nature means she will abide by the terms of any bargain, but she turns against the adventurers if she senses a hint of betrayal.

In addition to various treasures plundered from this level, Skella has a dagger she stole from Azrok, the hobgoblin warlord who rules Stromkuhldur on level 3 of Undermountain (see “area Legion of Azrok"). Returning this dagger to Azrok completes a side quest.

Umber Hulks

The umber hulks that burrowed into the Lost Level now wander freely here in search of prey.

A wandering umber hulk detects nearby characters with its tremorsense. Such a creature might come stomping down a corridor toward them at any time, smashing through any doors in its path. Or it could burrow through a wall to reach the characters, exploding forth in a hail of stone fragments. If a wandering umber hulk is defeated, remove it from area area 26 or have only one umber hulk in area area 34. If the characters have already defeated the three umber hulks in those areas, assume this wandering one is a new arrival.

Exploring This Level

All location descriptions for the Lost Level are keyed to map 6.

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(Player Version)

Many of the stone doors on this level have been demolished by the umber hulks. Creatures can move through the debris without penalty.

Quartz pillars found throughout the Lost Level shed bright light in a 20-foot radius and dim light for an additional 20 feet. Casting a successful dispel magic spell on a pillar (DC 12) extinguishes its magical light forever, as does destroying the pillar. A quartz pillar is a Huge object with AC 11, 50 hit points, and immunity to poison and psychic damage. The quartz pillars aren’t load-bearing, and their destruction won’t trigger a roof collapse. Characters who have the Stonecunning trait can discern this fact by examining the pillars (no check required).

1. Umber Hulk Tunnel

This 8-foot-high tunnel was dug by the umber hulk in area area 26 and is strewn with debris. The tunnel splits into two branches before breaking into a dark dungeon corridor on this level.

2. Acolytes' Vestry

Claw Marks. The walls are gouged with claw marks left by an umber hulk.

Wreckage. Three large wooden wardrobes have been pulled over and smashed on the floor.

Broken Door. The south door is smashed to bits.

Treasure

A character who searches the wrecked wardrobes finds a hematite pendant in the shape of a mountain, inset with a blue eye agate (25 gp). The pendant is a holy symbol of Dumathoin.

3. Cleansing Chamber

Basins. Three dry stone basins are evenly spaced across the east wall.

Cabinet. The doors of a stone cabinet in the southwest corner hang open.

The cabinet’s former contents have been cast onto the floor: crumbling bars of soap, steel-bristled wooden brushes, and washcloths so old they disintegrate when handled.

4. Ransacked Room

Duergar ransacked this chamber and left the door ajar. Ceremonial relics that once rested atop stone tables and sat in wall niches lie smashed and worthless on the floor. These include iron censers, stone candlesticks, polished crystal orbs, and black funeral helms.

Symbol of Dumathoin

Many areas of this level feature the symbol of Dumathoin, a mountain peak with a gemstone at its heart. The symbol is recognized by any character who succeeds on a DC 15 Intelligence (Religion) check. Dwarves succeed on the check automatically.

5. Looted Reliquary

This room once held ritual art and religious statuary. Shelves and curios once lined the north and south walls but now lie shattered and spread across the floor.

Treasure

The duergar who looted this room failed to appreciate the value of the art here. Characters who search the room find a chipped, 10-inch-tall lapis lazuli statuette of a dwarf king (75 gp), a funeral shroud with shards of blue quartz sewn into it (125 gp), and a 1-foot-tall, 3-foot-long alabaster triptych depicting a dwarven wedding (250 gp). The triptych weighs 25 pounds.

6. Workshop

Work Areas. Four work areas line the east wall, each consisting of a stout desk and a swiveling stool.

Lanterns. Above each stool, a lantern hangs by a chain anchored to the ceiling.

Metal Shop. A space dedicated to metalworking is housed in the southwest corner.

A search of the work areas yields one set of jeweler’s tools and one set of tinker’s tools. The lanterns above the work areas need oil but are otherwise functional.

The metalworking space contains an adjustable wooden worktable, a conical iron furnace, and a cracked water barrel that now sits empty and dry. Tools, chain mail aprons, and leather gloves hang from hooks along the walls.

7. Library and Scriptorium

Dwarves only rarely commit words to paper, making this dwarven library a rare find. Characters who make no effort to conceal their approach are detected by the creatures in this room, which has a 20-foot-high vaulted ceiling. The room contains the following:

Shelves. Scrolls bound in copper wire line stone shelves embedded in the east and west walls.

Monsters. Four duergar are rooting through the collected works, and a single cloaker lurks in the shadows of the vaulted ceiling.

Ladders. Sliding iron ladders on rails allow access to the tallest shelves, which top out at 15 feet high.

Desks. Two rows of stone desks and chairs face the entrance. The tops of the desks are angled slightly and have inkwells carved into them.

Caught off guard by the arrival of visitors, the duergar instinctively enlarge themselves and attack. If two duergar fall in battle, the survivors turn invisible and flee to area area 12 while the cloaker covers their escape.

The holy texts and scrolls in this room are brittle and fall apart easily. Most of the manuscripts describe the day-to-day religious observations of the priests of Dumathoin. A character who spends at least 1 hour poring over the archives can, with a successful DC 15 Intelligence check, discern the location of the temple of Dumathoin (area area 15). The character also gains advantage on ability checks to find secret doors on this level.

8. Park-and-Ride

The duergar searched area area 8a for treasure but didn’t find anything of interest. They also failed to detect the secret door to area area 8b.

8a. Donkey Dummies

Frescoes. The walls are carved with frescoes depicting dwarves defending their mountain homes against ankhegs, purple worms, umber hulks, and other burrowing monsters. (Hidden behind a fresco of a dwarf battling a bulette is a secret door that leads to area area 8b.)

Wooden Donkeys. Standing around the room are five crude wooden constructs resembling donkeys. Each of these magic dummies has a body made of a wooden keg turned on its side. A head and neck made of wood and sackcloth is attached to one end of the keg. At the other end is a tail made from a straw broom. Each keg is held up by four 2-foot-long peg legs.

When a Small or Medium humanoid sits atop a wooden donkey, it moves and attacks as directed by its rider. Each donkey has the statistics of a mule, with these changes:

  • The wooden donkey is a construct with blindsight out to a range of 30 feet. It is blind beyond this radius.
  • Without a rider, the wooden donkey is incapacitated.
  • It has immunity to poison damage, and it can’t be blinded, charmed, frightened, paralyzed, petrified, or poisoned.

8b. Arch Gate to Level 9

A stone arch embedded in the south wall is engraved with images of beholders, flumphs, and stirges. The arch is one of Halaster’s gates (see “area Gates"). Its rules are as follows:

  • If a creature flies or levitates within 5 feet of the arch, the gate opens for 1 minute.
  • Characters must be 10th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 13b on level 9, in the closest unoccupied space next to the identical gate located there.

9. Mustering Hall

Decor. Blunted picks hang with shields every 10 feet along the walls.

Double Door. Dwarvish runes for strength and safety are etched in the floor in front of the double doors to the east.

The doors to area area 10 are locked, and the key to unlock them can be found in area area 25. Characters who don’t have the proper key can open the double door using a knock spell or similar magic. It can also be forced open with a successful DC 30 Strength (Athletics) check. The lock on the doors can be picked by a character who makes a successful DC 15 Dexterity check using thieves' tools.

Pit Trap

In front of the double door, situated between the Dwarvish runes carved into the floor, is a hidden 20-foot-deep pit that opens if the lock on the doors is successfully picked. The cover of the pit can be spotted by a character who searches the floor for traps and succeeds on a DC 20 Wisdom (Perception) check. The pit automatically closes again if the double doors are relocked.

The pit is filled with a corrosive gas that billows up through tiny holes in its floor. Any creature standing before the double doors when the pit opens must succeed on a DC 15 Dexterity saving throw or fall in, taking 7 (2d6) bludgeoning damage from the fall and 10 (3d6) acid damage from the gas. A creature in the pit takes the acid damage again at the start of each of its turns.

The pit’s sheer walls can’t be climbed without the aid of climbing gear or magic.

10. Royal Armory

The double doors to this room are locked but easily opened from the inside. The key to the lock is found in area area 25. The features of this room are as follows:

Quartz Pillars. Four glowing quartz pillars cast bright light throughout the room.

Mannequins. Twenty dwarf-sized wooden mannequins stand in two rows of ten in the middle of the room.

Racks. Stone racks mounted on the west and east walls hold battleaxes and war picks.

Arch. Set into the back of a deep alcove to the south is a stone arch engraved with images of dancing dwarves.

Arch Gate to Level 5

The arch in the south alcove is one of Halaster’s magic gates (see “area Gates"). Its rules are as follows:

  • Standing within 5 feet of the arch and imitating the moves of the dancing dwarves carved into it causes the gate to open for 1 minute. The dance requires 1 minute to perform.
  • Characters must be 8th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 9 on level 5, in the closest unoccupied space next to the identical gate located there.

Armor and Weapons

The racks contain a total of twenty suits of dwarf-sized scale mail, twenty battleaxes, twenty war picks, and twenty steel shields emblazoned with the symbol of Dumathoin. All the equipment is in excellent condition.

The mannequins are all fitted with suits of scale armor and steel shields in good condition.

11. King’s Walk

This interconnected series of rooms tells the story of King Melair’s life in art. The duergar have looted each chamber.

11a. Training Years

Pillars. Stone pillars support a series of stone arches beneath a 30-foot-high domed ceiling.

Frescoes. Stone panels set into the walls bear frescoes and Dwarvish runes.

The frescoes chronicle the birth of Melair, a common shield dwarf, and his early years struggling as a brewer, metalsmith, and stonecarver.

11b. Prospecting Years

Frescoes. Stone panels set into the north and south walls bear frescoes and Dwarvish runes.

Displays. Three objects are displayed on stone blocks in the middle of the room, each encased under glass. A fourth display has been plundered, its glass broken and its object stolen.

Three historical objects are on display here—a rusty iron trowel that Melair used to spread mortar, the claw of a wyvern, and an orc’s split helm. (The duergar stole the fourth item, a golden gauntlet of elven design. It can be found in area area 15a.)

The frescoes depict Melair’s early exploits as a prospector: building a bridge over a river, meeting his first elf, prospecting for ore and gems in caves and foothills, hiding from orcs, and fighting a wyvern. In each scene, he is joined by a small company of dwarf prospectors.

11c. Coronation

Frescoes. Stone panels set into the west and south walls bear frescoes and Dwarvish runes.

Pedestals. Six stone pedestals stand before the frescoes, surrounded by shattered glass.

The frescoes show Melair, a shield dwarf prospector, discovering veins of mithral under a mountain and sharing the wealth with “kith and kin.” It shows dwarves flocking to the Underhalls of Melairbode, the subsequent formation of the Melairkyn clan, Melair’s coronation as king of the clan, and the gifts given to the newly acclaimed king by various dwarf families in attendance.

The duergar smashed the glass cases atop the pedestals and stole all the items on display. The items here were gifts given to King Melair during his coronation—the same gifts represented in the frescoes. Characters who examine the frescoes can ascertain what was stolen: a gem-studded cloak, an onyx smoking pipe, a fist-sized diamond, a red crystal tankard, and a golden belt with an obsidian buckle and studs. (These items can all be found in area area 15a.)

11d. Cradle and Crown

Frescoes. Stone panels set into the north and east walls bear frescoes and Dwarvish runes.

Bier. Resting atop a marble bier in the middle of the room is a carved stone rocking cradle.

The frescoes depict Melair spending time with his wife, their children, and their children’s descendants.

The cradle weighs 500 pounds and is an art object worth 2,500 gp. It contains a 2-foot-long statue of a swaddled dwarf infant sleeping soundly. A detect magic spell reveals an aura of transmutation magic around the statue of the dwarf infant.

Treasure

If the infant statue is removed from the cradle, it transforms into a crystal crown (250 gp) that reflects color as a prism does. This crown is needed to activate two of Halaster’s gates: area on level 8 in area 18b and area on level 11 in area 11a.

11e. Life in Undermountain

Stone panels set into the west and east walls of this 20-foot-high room bear frescoes and Dwarvish runes that tell of King Melair’s obsession with mithral. The discovery of vast veins of that metal in the Seadeeps (beneath what is today Mount Waterdeep) is recorded, as is Melair’s determination to rid Undermountain of its infestations of beholders, duergar, and drow.

When the characters first enter this room, ghostly orbs of light arranged like the eyes of a beholder appear in the middle of the room. This spectral display is one of Halaster’s harmless regional effects (see “area Halaster’s Lair") and lasts for 1 minute.

12. Mithral Thieves

Any creatures that escaped from area area 7 regroup here and will make a final stand in this area, the features of which are as follows:

Wall Carving. The south wall bears a lavish carving of a mountain, beneath which a large stylized eye looks down on a line of dwarf warriors.

Monsters. Five enlarged duergar occupy the 10-foot spaces in front of the carving, examining the mithral filigree. Two xorn stand watch in the middle of the hall, feeding on discarded mithral fragments.

Broken Door. The door to the north has been reduced to rubble, creating an open passageway.

The occupants of this area are tenuous allies. The duergar attack anyone they don’t recognize, and the xorn assist as best they can. If the duergar are defeated, the xorn disengage from combat on their next turn and flee by burrowing into the walls. If the xorn escape, the characters can encounter them again in other nearby chambers at your discretion. The xorn become indifferent toward characters who feed them gems and precious metals.

Treasure

The carving on the south wall is inlaid with mithral filigree. Ambitious characters can strip a total of 20 pounds of mithral from the walls. One character can strip 1 pound of mithral in 15 minutes. Each pound of the metal is worth 50 gp.

13. High Priest’s Chambers

The duergar ransacked this room but left a few treasures behind. The room has the following features:

Furnishings. Scattered about the room are the remains of a bed, an armoire, a desk, and a chair.

Scrolls. Heaped around the broken desk are hundreds of torn-up scrolls all bearing religious sermons.

Secret Door. A secret door in the east wall opens into a dusty, cobweb-filled corridor that connects to area area 14. (Characters inside the tunnel can spot the secret door at either end of it without having to make a check.)

Treasure

A spell scroll of mass cure wounds is buried under the pile of torn-up sermons next to the desk. A character who searches the pile finds it automatically.

14. Grand Vestibule

Rough Walls. The walls of this area are roughly hewn to give the room a cavern-like appearance.

Quartz Pillars. The glow from four quartz pillars reflects off flecks of quartz embedded in the walls.

Engraved Doors. The double doors to the south are engraved with the image of a mountain with a gem-shaped indentation at its core (the symbol of Dumathoin). The edges of the indentation serve as handles that enable the doors to be pulled open.

Secret Door. A secret door in the east wall opens into a dusty, cobweb-filled corridor that connects to area area 13. Characters inside the tunnel can spot the secret door at either end of it without having to make a check.

The first time a creature passes between the quartz pillars to the north, a booming, disembodied voice says in Dwarvish, “Neither secrets nor treasures shall ye find! Turn back! Ye are not welcome here!” Characters who have heard Halaster speak recognize the voice as his. Once all creatures leave this area, the magical warning resets.

15. Temple of Dumathoin

This huge chamber has been sculpted to resemble a cavern with a 30-foot-high vaulted ceiling.

15a. Nave

Monsters. Eight duergar plus their leader, a half-shield dwarf, half-duergar named Skella Ironeye, are scattered throughout the area. Two Cloaker flap above them, circling the nave at a height of 20 feet. The cloakers consider the duergar their allies.

Quartz Pillars. Glowing quartz pillars stand around the temple perimeter, carved to look like natural columns. The glowing pillars have the appearance of buttresses, but only the four stone pillars in the middle of the nave support the roof.

Dais. At the south end of the temple, stone steps climb 10 feet to a golden marble dais (area area 15b).

Although her mother was a shield dwarf, Skella has the statistics of a duergar with 40 hit points. She has also attuned to a magic dagger that gives her blindsight out to a range of 30 feet (see “Treasure” below).

When Skella and her duergar subordinates climbed to the top of the dais, the altar there released a clay golem that attacked them (see area area 15b). Four duergar were smashed to a pulp before Skella realized that their weapons were having no effect on the golem. She ordered her remaining forces to fall back, whereupon the golem withdrew to the altar once more.

Skella is prepared to let the adventurers take a crack at defeating the golem, so that she can find out what lies beyond the basalt doors. When the characters arrive, she tries to forge a truce with them, promising them safe passage through the Lost Level if they defeat the golem and depart the temple. Being lawful, she is inclined to uphold her end of the agreement as long as the characters don’t cross her.

Treasure

Skella wears a gem-studded cloak fit for a king (worth 750 gp, and stolen from area area 11c). Fastened to her belt in plain view is a small gold figurine of a female elf holding up a symbol of the sun (25 gp). This figurine is the key to opening the arch gate in area area 27.

Tucked in a sheath strapped to Skella’s right boot is a dagger of blindsight. The magic dagger was stolen from the hobgoblin warlord Azrok on level 3 and is the subject of a potential side quest (see “area Legion of Azrok"). This rare magic item requires attunement. A creature attuned to it gains blindsight out to a range of 30 feet. The dagger has a saw-toothed edge and a black pearl nested in its pommel.

Two other duergar carry treasures plundered from the other areas of this level in gray, soot-stained sacks. The sacks contain the other items stolen from area area 11c—an onyx smoking pipe (75 gp), a fist-sized diamond (1,000 gp), a red crystal tankard (250 gp), an elf warrior’s golden gauntlet (250 gp), and a golden belt with an obsidian buckle and studs (250 gp).

15b. Dais

Corpses. Four mutilated duergar corpses are sprawled on the steps of the dais.

Altar and Statues. A clay altar is flanked by 10-foot-tall statues of dwarves outfitted in ceremonial purple-and-gold armor and eyeless helms. (The statues are impressive-looking but harmless.)

Basalt Doors. At the back of the dais stands a set of double doors made of carved black basalt, flanked by two glowing quartz pillars. Above the double doors is a bas-relief carving of a mountain with a gem at its heart (the symbol of Dumathoin).

The altar is a block of clay 7 feet long, 4 feet wide, and 3 feet high. When any creature moves within 20 feet of it, an 8-foot-tall clay golem with dwarf-like proportions erupts from an extradimensional space inside the altar. The golem can exit or enter the altar as an action. The altar is impervious to damage.

The golem can’t be reasoned with. It enters the altar again only if it perceives no threats on the dais. If it goes berserk, the golem abandons its role as guardian and leaves the dais in pursuit of fleeing creatures.

If the characters defeat the golem or lure it away, any duergar in the temple seize the chance to approach the black basalt doors and inspect them more closely.

Basalt Doors

These matte black doors are impervious to damage and held shut by a power that neither magic nor force can overcome. The doors appear to absorb all light, but a close inspection reveals Dwarvish inscriptions carved into them that translate as follows: “It is the will of the Keeper of Secrets under the Mountain that only the hand of the king may open these doors. Let all who enter gaze upon the heart of Melairbode and know the true power of dwarvenkind.” Any character who succeeds on a DC 20 Intelligence (History) check knows that Melairbode is the name of the ancient dwarven realm beneath Mount Waterdeep, whose Underhalls were the foundations of Undermountain.

If the hand of a living or dead dwarf king is pressed against either door, both doors swing slowly inward, revealing area area 16 beyond. (The characters can find such an appendage in King Melair’s true tomb, area area 29f.) If the doors are touched by anything other than the hand of a dwarf king, the symbol of Dumathoin above the double doors casts a Bigby’s hand spell.

The shimmering hand created by the spell has 80 hit points and a +6 bonus to initiative. (See the spell description for the hand’s other statistics.) On each of its turns, this hand flies up to 60 feet and makes one clenched fist attack against a random creature on the dais. The spell has a duration of 1 minute. It can be triggered repeatedly, though a new hand can’t come forth until an existing one is gone.

16. Heart of the Mountain

The Melairkyn dwarves carved this 20-foot-high room out of the rock at the point they believed was the heart of their subterranean realm. The features of this room are as follows:

Door Handles. The black basalt doors leading to the dais (area area 15b) have handles on this side and are easily pulled open from within.

Mithral Veins. Thin veins of mithral spread across the hewn walls, looking like gleaming cracks in the stone.

Tapestry. A huge tapestry depicting a dwarven kingdom under a mountain hangs from an iron rail and spans the south wall. The tapestry is so old that it begins to crumble if any attempt is made to handle or move it.

Mirror. A tall oval mirror is mounted on the east wall. Carved into its stone frame are dozens of lidless eyes and the following phrase in Common: “The gate cannot hide from those it cannot see.”

While in this room, dwarf characters can sense the immense weight of the mountain gently pressing down on them and realize subconsciously that they can attune to this room as though it were a magic item. A legend lore spell or similar magic reveals that this room sits at the heart of the mountain and that the Melairkyn dwarves came here to learn secrets and receive divine guidance.

While attuned to the room and inside it, a dwarf can cast the divination spell at will. Answers provided by the spell come from an unknown source (perhaps the Keeper of Secrets under the Mountain, perhaps the mountain itself). Too many castings of the spell in a short amount of time can lead to false readings, as noted in the spell’s description.

Creatures that finish a short or long rest in this chamber absorb some of the strength of the mountain around them and gain 10 temporary hit points, or 20 temporary hit points if the creature is a dwarf. Once a creature gains this benefit, it can’t do so again until the next dawn, and then only after finishing a short or long rest.

Mirror Gate to Level 10

The mirror is one of Halaster’s gates (see “area Gates"). Its rules are as follows:

  • The gate opens for 1 minute when an invisible creature stands directly in front of the mirror.
  • Characters must be 11th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 4b on level 10, in the closest unoccupied space next to the identical gate located there.

17. Priests' Study

This room was once a quiet study space for deacons of the temple, but it has been ransacked by the duergar. This area contains the following features:

Toppled Statuary. Statuettes that once stood in shallow niches along the walls lie toppled and shattered on the floor.

Smashed Diorama. An alabaster diorama that depicted a meeting between elves and dwarves has been smashed to pieces, along with the stone table on which it once rested.

Broken Desk. A stone desk has been broken in two, its chair knocked over and cracked.

18. Hemisphere of Horrors

This hemispherical chamber has a 30-foot-high domed ceiling and contains the following:

Guardians. Two Helmed Horror of dwarven stature wield battleaxes instead of longswords and stand in front of the doors to area area 19.

Quartz Pillars. The room is brightly lit by four quartz pillars.

The helmed horrors won’t attack dwarves, including duergar, except in self-defense. They stand aside when approached by any dwarf, allowing those creatures to enter area area 19 freely. Other creatures that approach the helmed horrors are attacked. The helmed horrors understand Dwarvish but can’t speak.

19. Mountain Shrine

Statues. Four statues representing the dwarven deities Moradin (god of creation), Berronar Truesilver (god of hearth and home), Clangeddin Silverbeard (god of battle), and Marthammor Duin (god of exploration) stand in niches at the corners of this room.

Mouthpiece. Lying at the foot of Clangeddin Silverbeard’s statue is a tiny, tapered cylinder of worked brass—the mouthpiece for the tuba in area area 40.

20. Wall of Gemstones

Carved into the northeast wall is a fresco that depicts dwarves tossing gems into the mouth of a giant xorn.

Treasure

The gemstones in the fresco are real and can be pried from the wall with a knife or similar tool. Six banded agates (10 gp each), nine moss agates (10 gp each), four carnelians (50 gp each), three citrines (50 gp each), and an amethyst (100 gp) can be acquired.

21. Gem-Cutters' Workshop

An umber hulk barged into this room from the north and exited to the south, destroying two stone doors and much of the room. This area contains the following:

Quartz Pillars. Four quartz pillars fill this room with bright light.

Work Areas. Four work areas in the middle of the room meant for gem-cutting have been reduced to rubble.

A character who searches through the rubble can salvage one set of jeweler’s tools.

22. Gem Extraction

Rocks containing gemstone deposits would be transported to this area to have the gems expertly extracted by the Melairkyn dwarves.

22a. Xorn Orts

Tables. Four 20-foot-long, 5-foot-wide, 3-foot-high stone tables stand in the middle of the room.

Xorn. Piles of broken rocks surround the tables, some as high as 6 feet. A xorn is picking through the rocks and licking the gem dust off them.

If it notices the characters, the xorn approaches them and demands gemstones and precious metals, speaking in Terran. The xorn can sense if the characters are carrying such treasure, and it attacks if its demands aren’t met.

22b. Open Pit

The dwarves disposed of rocks by casting them into pits. When a pit became full, it was covered using stone shape spells and a new pit was created.

This open pit is 10 feet wide and 70 feet deep, but it’s filled with rocks to a depth of 50 feet. Creatures knocked into the pit fall 20 feet, taking 7 (2d6) bludgeoning damage.

23. Stripped Room

Four quartz pillars illuminate this otherwise empty room. Temple guests used to be quartered here, but Halaster had the area stripped of its furnishings years ago.

24. Arch Gate to Level 2

Temple workers were once housed here, but Halaster had this chamber’s furnishings destroyed. The room is now empty except for an arch gate set into the east wall (see “area Gates"). Carved into the arch gate’s keystone is an image of a rust monster. The rules of this gate are as follows:

  • Touching the arch with a nonmagical item made entirely of ferrous metal (such as an iron spike) reduces the item to powdered rust and opens the gate for 1 minute.
  • Characters must be 6th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 20c on level 2, in the closest unoccupied space next to the identical gate located there.

25. Dwarven Den

Stone couches and tray holders occupy the northeast and southwest corners. Lying on the dusty floor beneath one of the couches is an iron key that unlocks the double doors to area area 10. A search of the room reveals the key.

26. Sacred Spirits

Characters approaching this room hear a loud ruckus. The chamber’s stone door has been smashed to rubble, and a hostile umber hulk is laying waste to the room. The hulk’s tremorsense allows it to detect other creatures approaching on foot. When the characters get close, it crashes through the wall north of the doorway, hoping to surprise them.

The dwarves kept alcoholic spirits here. The beverages are long evaporated, and the umber hulk has pulverized the stone shelves, vats, and bottles that remain. Nothing here is salvageable.

27. Arch Gate to Level 4

Embedded in the south wall is an archway with six shallow, empty niches carved into it. The wall inside the arch is carved with a stylized image of a mountain with a sun above it.

The arch is one of Halaster’s magic gates (see “area Gates"). Its rules are as follows:

  • If the elf figurine taken from Skella in area area 15a is touched to the sun symbol, the gate opens for 1 minute.
  • Characters must be 8th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 10 on level 4, in the closest unoccupied space next to the similar gate located there.

28. False Tomb

This chamber is dressed to fool treasure seekers into thinking they have found the tomb of the Melairkyn king. Its features are as follows:

Quartz Pillars. Six glowing quartz pillars fill the room with bright light.

Detritus. Rusted helms, shields, armor fragments, and weapons cover the floor. This detritus makes the entire room difficult terrain. (The arms and armor were fashioned by orcs, goblinoids, drow, duergar, and other enemies of the dwarves. No dwarven items can be found among the wreckage.)

Sarcophagus. A deep alcove in the north wall is mostly clear of metal wreckage and contains a shattered stone sarcophagus. Engraved in the back wall of the alcove is a Dwarvish inscription that reads, “Our king is with the gods. Here lie his bones.”

Secret Door. A secret door in the south wall swings open into area area 29a.

Dwarven bones are scattered around the smashed sarcophagus, but a character who studies the wreckage and succeeds on a DC 20 Intelligence (Investigation) check can tell that the scene has been cleverly staged to fool tomb robbers.

29. King Melair’s Lost Tomb

The dwarves have left many surprises here to prevent tomb robbers from reaching their king’s resting place.

29a. Second False Tomb

Ceiling. This tomb has a 10-foot-high, vaulted ceiling.

Sarcophagus. A black marble sarcophagus flecked with gold stands close to the south wall, its lid carved in the likeness of a dwarf king.

Crystal Panels. Ten glittering panels are set into the west, south, and east walls. Each panel is a 6-foot-tall, 3-foot-wide, 1-inch-thick rectangle of golden crystal, carved with the bas-relief image of a dwarf warrior clutching a battleaxe. (The panel in the middle of the south wall is set into a secret door that swings open into area area 29b.)

The lid of the sarcophagus can be lifted by creatures with a combined Strength of 20 or more. Removing the lid triggers a magic mouth spell that admonishes interlopers in Dwarvish: “You dishonor our beloved king! May his tomb become yours as well!” After this warning, all ten battleaxes break free of their panels (whether on the walls or not; see “Treasure”) and attack the tomb’s interlopers. Use the flying sword statistics for each crystal battleaxe.

The sarcophagus contains tatters of a black shroud, the dust and bones of a nameless dwarf, and the bones of a mole that was accidentally sealed in with the dwarf’s remains.

Treasure

The crystal panels can be carefully pried from the walls. Each panel weighs 50 pounds and is worth 500 gp, or 50 gp without its crystal battleaxe.

29b. First Interstitial Hall

This hall is choked with dust and cobwebs. It ends in an unlocked door that opens into the next hall.

29c. Second Interstitial Hall

This hall is choked with dust and cobwebs. It ends in a blank wall that holds a hidden secret door. The secret door is locked, and the mechanism to unlock it is located at the bottom of a hidden pit.

Pit Trap

The pit in this hall is 10 feet wide and 30 feet deep. A character who searches the floor for traps and succeeds on a DC 20 Wisdom (Perception) check spots the trap. When a weight of 50 pounds or more is placed on the cover of the pit trap, the cover swings open like a trapdoor, causing any creature standing on it to fall in and take 10 (3d6) bludgeoning damage. The pit remains open for 1 minute; then its cover rises up on hidden springs and snaps shut. A successful DC 20 Strength check can pry the pit open. Hammering spikes or pitons into the edge of the pit’s lid prevents it from opening.

A character in the pit can disable the spring mechanism from the inside with a successful DC 15 Dexterity check using thieves' tools, as long as the character can reach the mechanism at the top of the pit and can see.

Hidden among the flagstones on the pit’s floor is a stone button that, when pressed, unlocks the secret door to area area 29d. A character who searches the bottom of the pit can find the button with a successful DC 12 Wisdom (Perception) check.

29d. Gods and Demons

Statues. Watching over this chamber are four 9-foot-tall stone statues of imperious dwarves.

Tapestry. Hanging on the south wall between the statues of Moradin and Berronar is a thick tapestry depicting King Melair, his adamantine war pick in hand as he battles a purple worm. (The tapestry is too moldy and frayed to be worth anything.)

Magic Wall. The wall behind the tapestry is a magical conjuration. It doesn’t detect as such under the scrutiny of a detect magic spell, but it vanishes if targeted by a successful dispel magic spell (DC 16). It also ceases to exist while contained in the area of an antimagic field spell. It otherwise looks and feels solid.

The statues represent the dwarven deities Moradin (god of creation), Berronar Truesilver (god of hearth and home), Clangeddin Silverbeard (god of battle), and Marthammor Duin (god of exploration). A demon is trapped in each statue (see “Trapped Demons” below).

Each statue is a Large object with AC 15, 100 hit points, and immunity to poison and psychic damage. Toppling a statue requires a successful DC 22 Strength (Athletics) check. A statue that topples or takes 10 or more damage cracks enough for the demon inside to erupt in a cloud of reeking black mist. It then coalesces into its true form in the nearest unoccupied space.

Trapped Demons

The Melairkyn dwarves trapped four demons in the statues after attempts to banish the fiends failed—a barlgura in the statue of Moradin, a hezrou in the statue of Berronar, a vrock in the statue of Clangeddin, and a glabrezu in the statue of Marthammor. Over the centuries of its confinement, the glabrezu has learned how to telepathically contact creatures in this room. Using its telepathy, it tries to trick an interloper into freeing it. Though the other three demons have telepathy, they are not powerful enough to use the ability while trapped in their statues.

The glabrezu makes telepathic contact with one character at random, congratulating that character on making it this far and claiming to have the knowledge and power to reveal the way to King Melair’s true tomb. It promises (truthfully) to do so in exchange for its release from captivity. If the glabrezu is released, it casts dispel magic on the wall behind the tapestry, granting access to areas area 29e and area 29f, then lets the characters desecrate King Melair’s tomb before it attacks them. If it needs allies, it knocks over more of the statues to free the other demons. These weaker demons obey the glabrezu for as long as it benefits them to do so.

If the first character it approaches refuses to help the glabrezu escape, it makes contact with each of the other party members in turn. If it realizes none of the characters can be swayed, it screams vile epithets and vows to destroy them whenever it is set free.

29e. Hidden Alcove

A secret door in the back wall of the alcove opens into area area 29f.

29f. True Tomb

A stone dais supports the true sarcophagus of King Melair—a perfectly cut slab of white marble with the name “Melair” etched in silver atop it in Dwarvish lettering. The lid of the sarcophagus can be lifted by creatures with a combined Strength of 20 or more.

Treasure

Inside the sarcophagus is the mummified corpse of the dwarf king, clad in burial robes and clutching an adamantine war pick. A sentinel shield bearing the symbol of Dumathoin rests atop the king’s legs.

Characters who sever one of the king’s desiccated hands can use it to open the basalt doors in area area 15.

30. Mummification Chamber

Stone Block. In the middle of the room rests a granite block 8 feet long, 3 feet wide, and 2 feet tall.

Urns. Sixty limestone urns rest in dusty wall niches.

The dwarves once mummified their dead atop the stone block, which has shelves built into its sides. The funeral wrappings and embalming fluids once held here have either turned to dust or been destroyed.

Each limestone urn is sealed with wax. An urn contains the desiccated internal organs of a dead dwarf, removed during mummification.

31. Rest Area

This empty, dead-end area makes a good place for the characters to rest.

31a. Open Pit

A 10-foot-wide, 20-foot-deep pit stands open between parallel corridors to the north and south. The springs that held the pit’s cover shut have rusted to the point of malfunction, exposing the trap.

31b. Empty Room

Once used as quarters by Undermountain engineers, this room now contains nothing but dust.

32. False Halaster

The characters encounter an invisible, wandering gray slaad here. The slaad serves Halaster willingly and is tasked with killing adventurers on sight. Using its Shapechanger trait, the slaad has assumed Halaster’s appearance, which becomes apparent when it swings its greatsword and ceases to be invisible.

33. Ghohlbrorn’s Grave

The Dwarvish word for bulette is “ghohlbrorn,” and one of King Melair’s greatest battles was fought against such a creature. After defeating the bulette, the king had its body animated to serve as an undead guardian.

33a. Tomb of the Ghohlbrorn

This chamber has a flat, 30-foot-high ceiling and 10-foot-high tunnels exiting it to the west, south, and east.

Statues. Alcoves to the north hold four identical statues, each one bearing the likeness of a 10-foot-tall dwarven king of stern visage.

Hidden Grave. The 20-foot-by-30-foot section of floor in the middle of the room is covered with breakaway stone tiles. (These tiles cover a grave.)

Tapestry. A torn tapestry hangs from an iron rod mounted to the south wall. The tapestry depicts King Melair and his guards fighting a bulette in a gem-encrusted cavern.

Any character who has the Stonecunning trait notices the breakaway section of floor immediately (no check required). Others who search the floor for traps notice the breakaway tiles with a successful DC 15 Wisdom (Perception) check. Beneath the breakaway stone tiles, an earth-filled cavity holds an undead bulette. Once all four exits are blocked by the statues, the undead bulette erupts from the floor and attacks all creatures in the room. This creature is a bulette, with these changes:

  • It is undead and has 125 hit points.
  • It has vulnerability to radiant damage, resistance to necrotic damage, and immunity to poison damage and the poisoned condition.

If it has nothing to attack, the undead bulette burrows back down into its earthen cavity.

33b. Spiked Pit

This hidden pit is 10 feet wide, 30 feet deep, and lined with adamantine spikes. A character who searches the floor for traps and succeeds on a DC 15 Wisdom (Perception) check spots the trap.

When a weight of 50 pounds or more is placed on the cover of the pit trap, it swings open like a trapdoor, causing any creature standing on it to fall in. The creature takes 10 (3d6) bludgeoning damage from the fall and 11 (2d10) piercing damage from the spikes. The pit remains open for 1 minute; then its cover rises up on hidden springs and snaps shut. A successful DC 20 Strength check can pry the pit open. A character in the pit can try to disable the spring mechanism from the inside with a successful DC 15 Dexterity check using thieves' tools, provided that the mechanism can be reached and the character can see it.

34. Refectory Rampage

The doors leading to this section of the dungeon have been smashed to pieces, and characters approaching the area can hear large creatures wreaking havoc within.

34a. Temple Refectory

Umber Hulks. Two Umber Hulk stomp about the room. They attack other creatures on sight.

Wreckage. Smashed dining tables and benches create a makeshift obstacle course and provide cover.

Arch Gate to Level 12. A stone arch is embedded in the middle of the south wall.

The arch is one of Halaster’s magic gates (see “area Gates"). Carved into its keystone is an image of a hand pouring ale from a flagon. Its rules are as follows:

  • If one pint or more of any liquid is poured on the floor within 5 feet of the arch, the gate opens for 1 minute.
  • Characters must be 12th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 9d on level 12, in the closest unoccupied space next to the identical gate located there.

34b. Arch Gate to Level 8

This room is empty except for an arch embedded in the northeast wall. This arch is one of Halaster’s magic gates (see “area Gates"). The space inside the arch bears a bas-relief of a female dwarf standing with her eyes closed. A large keyhole is carved into the head of a stone hammer she clutches to her chest. The rules of this gate are as follows:

  • If the stone key from area area 14a on level 2 is inserted into the keyhole, the bas-relief and the key vanish as the gate opens for 1 minute. When the gate closes, the bas-relief reappears, and the key is ejected from its keyhole.
  • A character can open the gate without the stone key by using an action to pick the lock, requiring a successful DC 20 Dexterity check using thieves' tools. On a failed check, the dwarf’s eyes open and shoot forth beams of light. Each creature within 10 feet of the arch must make a DC 16 Dexterity saving throw, taking 22 (4d10) radiant damage on a failed save, or half as much damage on a successful one.
  • Characters must be 10th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 3 on level 8, in the closest unoccupied space next to the identical gate located there.

34c. Scullery

This room contains the smashed remains of a preparation table, a dishwashing station, and a stone cabinet. Scattered across the floor are pots, pans, and utensils, all corroded and worthless. A water pump to the northwest has survived the umber hulks' rampage, but it is rusted and no longer draws water.

35. Black Cloak

Halaster has created a regional effect in this corridor (see “area Halaster’s Lair"). As the characters come around the corner, they see a billowing black cloak moving away from them, as if it were being worn by an invisible creature. Created by a minor illusion spell, the cloak is silent and moves away from the party at a speed of 30 feet. It disappears upon entering area area 33a, area 34a, or area 36b, or if it is dispelled.

36. Temple Maintenance

This corner of the dungeon was originally set aside for dwarf engineers and maintenance workers.

36a. Service Entry

This corridor ends at a smashed door.

36b. Trash Compactor

Open Pit. In the middle of the floor is a 10-foot-wide, 30-foot-long, 20-foot-deep pit with a fine layer of dust and rubble on its floor.

Levers. Two stone levers protrude from the wall opposite the door to area area 36c. Dwarvish runes are inscribed above each lever.

The pit is a trash compactor designed to flatten garbage into sheets that can be easily carted away and disposed of.

The first lever is currently in the up position and has the word “Crush” inscribed above it. Moving this lever to the down position causes the pit’s east and west walls to close together, crushing anything between them. Raising the lever causes the walls to retract. Any creature or object crushed between the walls takes 44 (8d10) bludgeoning damage and is restrained by the walls until they retract.

The second lever is currently in the down position and has the word “Lift” inscribed above it. Moving this lever to the up position raises the stone floor of the pit to the level of the floor in the room. Neither this lever nor the pit floor can be raised while the pit walls are closed.

36c. Arch Gate to Level 3

Arch. An arch is embedded in the northwest wall. Its keystone is carved to show a gold dragon wyrmling with its mouth open.

Slaad. Two invisible Gray Slaad in their natural forms flank the arch. The slaadi are Halaster’s willing servants and attack anyone who approaches the arch or emerges from it, becoming visible as they do so.

Bunk Beds. Four stone bunk beds are pushed against the long walls of the room.

The arch is one of Halaster’s magic gates (see “area Gates"). Its rules are as follows:

  • The gate opens for 1 minute when a gemstone worth at least 100 gp is placed in the dragon’s mouth. This act causes the mouth to animate, chomp down on the gem, and destroy it.
  • Characters must be 7th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 21p on level 3, in the closest unoccupied space next to the identical gate located there.

37. Showers and Sauna

Temple workers came here to shower and bathe.

37a. Showers

Benches. Black marble benches stand in the middle of this marble-tiled room.

Showers. Alcoves in the west and east walls have rusted iron shower heads protruding from the ceiling. A rusty pull chain hangs near each shower head, and each alcove has drain holes in the floor. The showers draw cold water from an underground river.

Secret Door. A secret door in the back of the east alcove opens into area area 37c.

37b. Sauna

Heating Tank. Heat billows from vents built into the sides of an 8-foot-tall, 5-foot-diameter cylindrical copper tank in the middle of the room. A copper pipe extends upward from the tank and disappears into the ceiling. A fire elemental rages inside the tank.

Iron Wheel. A small iron wheel protrudes from the wall just inside the door.

Benches. Black marble benches hug the wall.

When cold water from an underground river is fed into the tank through the pipe, the fire elemental turns the water into steam. The steam billows out through vents in the cylinder’s sides, making the room into a sauna.

The tank is a Large object with AC 11, 45 hit points, and immunity to fire, poison, and psychic damage. If the tank takes more than 10 damage, the elemental escapes and attacks all other creatures it encounters until it is destroyed.

Rust has caused the iron wheel to seize up, and it takes a successful DC 15 Strength (Athletics) check to turn it. Turning the wheel clockwise sends water pouring down the pipe and into the tank.

37c. Hidden Shrine of Abbathor

This shrine to Abbathor, the dwarven god of greed, was built without the knowledge of the temple priests. It contains the following features:

Statue. Facing the secret door is an 8-foot-tall statue of a pig-eyed male dwarf sitting on a throne. Eight gemstones are embedded in the stone rings the dwarf wears on its steepled fingers.

Open Pit. In front of the statue is a 10-foot-deep open pit whose bottom is set with spring-loaded iron jaws, around which are chunks of rock and dwarven bones.

A temple acolyte found this shrine but failed to notice the pit, which was hidden under a false stone floor. When the false floor broke apart underfoot, the dwarf fell into the snapping iron jaws below. The false floor was never replaced, nor was the acolyte’s body removed. The spring-loaded iron jaws rusted and froze over time.

Treasure

The dwarf had a peg leg made of mithral (75 gp) but nothing else of value.

The gemstones set in the statue’s stone rings include two sardonyxes (50 gp each), two zircons (50 gp each), an amethyst (100 gp), two garnets (100 gp each), a spinel (100 gp), and a tourmaline (100 gp). They can be easily pried loose.

38. Wide Alcoves

This hall is flanked by two empty, semicircular alcoves.

39. Temple Reliquary

The dwarves kept many precious relics here.

The duergar have destroyed the relics on display here, including statues atop pedestals, stone tablets on easels, and elaborate dioramas on tables. All that remains are heaps of broken stone.

Illusory Wall

The west wall of the room is an illusion without substance. It vanishes if targeted by a successful dispel magic spell (DC 16), and creatures and objects can pass right through it.

39b. Jade Staff Fragments

Display Niches. Four pieces of a shattered jade staff are encased behind glass in niches evenly spaced along the west wall. Each niche is 4 feet tall, 1 foot wide, 1 foot deep, and lit with ambient magical light.

Secret Door. A secret door in the south wall opens into area area 39c.

The glass encasing each niche is easily broken, allowing access to the fragment inside. Shattering the glass in a niche causes the light in that niche to go dark.

Treasure

The jade staff is presently broken into five 1-foot-long pieces—the four that Halaster placed on display here, plus a fifth piece he cast away. A detect magic spell reveals no magical auras around the staff fragments. Each of the staff’s five pieces is worth 100 gp for the jade alone. The missing piece is the middle section of the staff, currently in the clutches of a bullywug (see area level 8, area 19c). Pieces one and two (the top two sections of the staff) can be restored to a single section with a mending cantrip, as can pieces four and five (the bottom two sections).

If the fifth piece is found, the entire staff can be restored with mending cantrips; each casting of the spell repairs one break in the staff. If the staff is made whole, it transforms from an object into an animated jade serpent that has the statistics of a giant poisonous snake, with these changes:

  • The serpent is a construct that understands and obeys whoever was holding the staff when it transformed.
  • It has immunity to poison damage and the poisoned condition. It doesn’t require air, food, drink, or sleep.
  • When it drops to 0 hit points, roll a d6. On a roll of 1, the snake turns to dust and is destroyed. On any other roll, it changes back into a staff and breaks into 1d4 + 1 pieces that must be magically mended before the staff can be used again.

39c. Mornhyld’s Bones

Bones. A dwarven skull and twelve rotted bones swirl gently around each other in midair in the middle of the room.

Debris. On the floor beneath where the bones are circling lies a shattered stone coffer.

Niche. Carved into the west wall is an empty niche. (The coffer once rested here.)

A dwarf priest named Mornhyld Crystalmantle bound her spirit to Undermountain for eternity. Most of her bones turned to dust long ago. What’s left of the dwarf floats above the shattered coffer, courtesy of Halaster’s magic. Casting a successful dispel magic spell on the bones (DC 16) ends the effect and causes the skeletal remains to clatter to the floor.

Mornhyld’s disembodied spirit can sense when any humanoid moves within 5 feet of the bones, and it immediately tries to possess that creature. The target must succeed on a DC 18 Charisma saving throw or become possessed by Mornhyld. While possessed, the target is incapacitated and loses control of its body, though it retains its awareness. The possession lasts until the target’s body drops to 0 hit points, the target leaves the room, Mornhyld’s spirit ends the effect as a bonus action, or the spirit is forced out by an effect such as the dispel evil and good spell. The creature is immune to the spirit’s possession for 24 hours after succeeding on the saving throw or after the possession ends.

If Mornhyld’s spirit fails to possess a creature, it can try to possess another creature on its next turn. The spirit has a +1 bonus to initiative.

Mornhyld’s spirit requires a host body before it can communicate. While possessing a humanoid, it uses that host to share the following secrets, doing so in the course of a brief conversation:

  • “The heart of the mountain is sealed behind doors of black basalt that only a dwarf king can unlock. In the mountain’s heart, you’ll find your own greatness.” (See area area 15.)
  • “When you enter a room, speak the word ‘xunderbrok’ for all to hear. You might be rewarded.” (Characters who understand Dwarvish know that the word means “secret trove.")
  • “Demons invaded our temple, but we trapped them in statues on this level. Beware them.” (See area area 29d.)

40. Music Hall

Characters who make no effort to conceal their approach alert the creatures in this 20-foot-high vaulted chamber, which is carved out of solid rock. The room contains the following:

Quartz Pillars. Glowing quartz pillars stand in the corners of the room.

Duergar. Two duergar are inspecting a stone arch embedded in the center of the east wall.

Instruments. Protruding from the south wall is an organ whose pipes are carved out of stalagmites. Its bench and keys are made of polished gold and black marble. Two large copper kettle drums stand against the west wall. Resting atop them is a shiny brass tuba.

The duergar have taken a break from looting to inspect the arch in the east wall. They turn invisible if they detect other creatures approaching, then move up behind the pillars to the north to take stock of the new arrivals. Then they sneak off to area area 15a to alert the duergar there. They avoid confrontation in this room. In addition to their weapons and armor, these duergar have treasure (see “Treasure” below).

Arch Gate to Level 11

The arch embedded in the east wall is one of Halaster’s magic gates (see “area Gates"). Carved into the arch’s keystone is a hand-shaped indentation with a sigil representing magic scribed into the palm. The rules for this arch are as follows:

  • Casting the mage hand cantrip and pressing its spectral fingers into the keystone’s indentation opens the gate for 1 minute.
  • Characters must be 11th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 2b on level 11, in the closest unoccupied space next to the identical gate located there.

Instruments

Any inspection of the room allows the characters to examine the instruments more closely.

Brass Tuba

This bulky instrument is missing its mouthpiece, which characters can find in area area 19. Without it, the tuba can’t produce its deep, distinctive sound. The tuba is worth 30 gp and weighs 30 pounds.

Kettle Drums

When struck, these two copper drums make a thunderous booming sound. Each drum is worth 50 gp and weighs 100 pounds.

Stalagmite Organ

This monstrous pipe organ produces deep, earthy tones from its hollow stalagmites when its stone pedals are pumped and its marble keys are played. The music of the organ not only fills this room but also magically sounds throughout the temple (area area 15), alerting the creatures there. If duergar are still present in the temple, four of them are sent to investigate the disturbance in this area and silence the music. The organ’s stalagmites were part of the cavern from which this room was hewn, and thus they blend seamlessly with the surrounding floor and wall.

Treasure

Each duergar carries a sack of stolen items. One sack contains a silver figurine of an ox (25 gp), a tiny mithral bell (25 gp), and a pewter flagon sculpted in the shape of a gold dragon with amethysts for eyes (250 gp). The other sack contains a small trapezoidal mirror set in an onyx frame (25 gp) and a leather eye patch with a bloodstone (50 gp) sewn into it.

41. Privies

This room is divided into four stone privies with holes cut into their floors and long-disused lavatory pits below. An invisible gray slaad lurks in the privy to the south. It attacks anyone who searches or uses its privy.

42. Hidden Pit

A breakaway stone floor in this corridor conceals a 10-foot-wide, 20-foot-deep pit. A character who searches the floor for traps and succeeds on a DC 20 Wisdom (Perception) check spots the irregular floor tiles. When a weight of 20 pounds or more is placed on the floor, it collapses, causing any creature standing on the pit to fall in and take 7 (2d6) bludgeoning damage.

In addition, a glyph of warding spell cast on the floor of the pit detonates when a creature falls in. When triggered, the glyph erupts with magical energy, and each creature in the pit must make a DC 22 Dexterity saving throw, taking 36 (8d8) fire damage on a failed save, or half as much damage on a successful one.

43. Umber Hulk Tunnels

These 8-foot-high tunnels were created by the umber hulks in area area 34. The three tunnels converge into one that descends as it travels southeast, eventually reaching level 7. All the tunnels are strewn with debris.

44. Acolytes' Quarters

This circular room has a domed ceiling 30 feet high and contains the following features:

Furnishings. Six stone beds rest with their headboards against the walls. A shallow niche stands empty above each bed. At the foot of each bed is a stone chest that has been smashed open.

Smashed Statuary. Alabaster statuettes of dwarf kings lie smashed on the floor. (The statuettes once stood in the wall niches. The duergar destroyed them, then broke into the chests and looted them.)

45. Acolytes' Quarters

This room has the same features as area area 44.

46. Blasted Chamber

The walls and floor of this 30-foot-high domed chamber have been blackened by fire, and the room’s furnishings appear to have been incinerated. Charred bits of wood and stone lie strewn about the floor.

Any character who examines the room and succeeds on a DC 20 Intelligence (Investigation) check realizes that some sort of magical conflagration caused the damage, and that it started in the middle of the room. There is nothing to indicate what triggered the devastation.

47. Halls of the Faithful

Devotees of Dumathoin once walked these halls to get from their quarters to the temple. Now, Halaster’s guardians and magic haunt these areas.

47a. Arch Gates to Levels 13 and 18

Corpses. The corpses of two duergar (one male, one female) lie sprawled in the center of the room.

Arch Gates. Two stone arches are embedded in the walls, one to the north and the other to the south.

Stalkers. Halaster placed two Invisible Stalker here. They attack any creature that approaches within 10 feet of either gate or that emerges from a gate.

The male duergar was killed first by the invisible stalkers. His companion came looking for him minutes later and met the same fate. Both duergar wear dull gray scale armor. Their iron shields, war picks, and javelins lie nearby. They have no treasure.

North Arch Gate

The north arch is one of Halaster’s magic gates (see “area Gates"). It is decorated with inlaid images of dancing goblins. The letter D is carved into the arch’s keystone. Its rules are as follows:

  • The gate opens for 1 minute if a creature stands within 5 feet of the arch and either sings a D note or plays a D note on a musical instrument.
  • Characters must be 12th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 7b on level 13, in the closest unoccupied space next to the identical gate located there.
South Arch Gate

This arch is another of Halaster’s gates, its sides carved in the form of scantily clad elves (one male and one female) holding fingers to their lips in a gesture of silence. Its rules are as follows:

  • If a silence spell is cast so that the arch is in the spell’s area, the gate opens for 1 minute.
  • Characters must be 15th level or higher to pass through this gate (see “area Jhesiyra Kestellharp"). The first creature to pass through the gate triggers an elder rune (see “area Elder Runes").
  • A creature that passes through the gate appears in area area 6 on level 18, in the closest unoccupied space next to the identical gate located there.

47b. Giggles

This hall forms a loop that contains one of Halaster’s regional effects (see “area Halaster’s Lair"). As the characters make their way around one side of the loop, they hear footfalls and giggling coming from around the next corner. The sounds stay ahead of them as they circle the loop, but stop if the characters come at them from two directions at once. This effect is the work of a harmless minor illusion cantrip.

48. High Priest’s Quarters

Alcoves. Seven empty alcoves stand along the walls.

Marble Bed. A white marble bed stands in the middle of the room, its corner posts carved to resemble dwarf warriors standing at attention.

Dead Duergar. At the foot of the bed is a stone trunk, its lid thrown open. The legs of a dead duergar stick out of the chest. Her war pick lies on the floor nearby.

The duergar opened the chest without noticing its trap and was shot to death by spring-loaded darts. Her companions carefully looted most of the chest’s contents, leaving her dart-riddled corpse hanging half out of it.

Aftermath

If the duergar are permitted to continue looting the level, they might find the lost tomb of King Melair, plunder its treasures, and venture back into the Underdark with them.

If the demons trapped in area area 29 are released, they become the dominant threat on this level, aggressively hunting down and destroying would-be treasure seekers.