Arcturiadoom

**Arcturiadoom** was the 14th level of the massive dungeon known as Undermountain. It served as the personal retreat of Arcturia, a unique lich who was infamous one of the most powerful of Halaster Blackcloak's seven apprentices.

## Description

Several of the hallways and alcoves were decorated with statues of Arcturia and Halaster himself. While Arcturia thoroughly made the domain her own, many chambers and rooms featured crypts and foundries, holdovers of the old Melairkyn dwarves. Among these was a large iron tankard that weighed over 1,500 lbs (680.4 kg) and several dwarf-sized statues that had escaped arcane transformation.

As Arcturia herself was a master transmuter, her domain contained a great number of traps that were designed to transmogrify and alter the form of any humanoid creature that happened to set them off. They typically came in the form of magical *glyphs*, inscribed into the domain's floors. While they could be easily *dispelled*, they had the potential to possibly alter the form of any interlopers to anything from otyughs to gelatinous cubes and even wyverns.

## Geography

### Entrances

* The great bore worm dug a large tunnel that led down from Trobriand's Graveyard to a cave that opened up into large set of double doors that featured carvings of skulls that had been eaten away by worms. Behind these doors was they foyer of Arcturiadoom, decorated with dwarven statues that had been grotesquely altered by Arcturia's magic.

### Notable Locations

Central hall

In the center of Arcturiadoom, down a hallway north of the entrance, was grand main hall. Its arched ceiling stood 150' (45.7 m) tall and was buttressed by broad stone pillars. It was illuminated by a number of sconces that were enchanted with *continual flames*.
Classroom

Like her master Halaster, Arcturia occasionally took on a number of apprentices and dedicated a portion of her domain to their education. However, their quarters were often empty and the classrooms were strewn with evidence of the displeasure she had in her pupils. In addition to words like *"YOU ALL FAIL"* being scrawled across the blackboard, the remains of several arcane apprentices could be found throughout this area of Arcturiadoom.
Disintegration room

Foundry

In the northwest section of Arcturiadoom was a large smithing room with an arched ceiling that reached 30'(9.1 m) high. The foundry itself was a vast room and three smaller chambers that extended beyond corresponding 70' deep (21.3 m) pits that, when active, were partially filled with bits of scrap metal. Within each chamber were stone stairs that led up to the three forges, whose flames were drawn from the Elemental Plane of Fire. The heat of the foundry was so intense it was harmful to anyone who spent more than an hour within, while the flame itself was comparable to that of the fiery breath of a young red dragon.
Laboratory

Arcturia kept a small, but often-used experimentation room in the eastern part of her domain. It featured a large stone operating table, atop which she kept the subjects of her transformative "innovations". Another room just off to the side of the lab had several chains linked to iron rings, which had been bolted to the floor. It gave the archmage a space to secure some of her particularly hideous creations.
Prison

North of the main entrance, down a pair of halls, was a half dozen holding cells where Arcturia kept her subjects before she could experiment upon them.
Timekeeping room

Within the halls of her realm, Arcturia kept an entire room dedicated to the marking of time, allowing her to keep track of the day and night cycle of Toril. An 20' (6.1 m) wide iron ring was suspended in the air, attached to the four pillars that extended into the room's partially-concave ceiling. Within this ring was a slightly smaller disc that was inscribed with a symbol of the sun on one side, and the moon on the reverse.
Two alcoves within the room contained life-size statues of human wizards, which had been heavily enchanted by evocation and transmutation magic. At dawn and dusk each day, the statues exerted arcane energy upon the disc, displaying the symbol of the sun during the daytime, and the moon at night.
Transmutorium

A single room in the northern part of Arcturiadoom held some of Arcturia's most horrifying creations. On the western wall hung a tapestry made of flesh, that was in fact the beholder Xebekal. After invading her lair, the eye tyrant was stripped of all its powers and transformed by means of a *wish* spell.
Hidden behind a crystal door within the transmutorium was a small alcove that held a magical device, comprised of a a brass panel and a number of buttons. Within this chamber any being could be made larger or smaller, as if they were affected by the spell *enlarge or reduce person*.

## Inhabitants

The halls of Arcturiadoom, along the caves outside, were inhabited by several types of creatures and humanoids native to the Underdark. Just outside the front entrance of the archmage's domain, a group of carrion crawlers dwelled within a small garden of luminescent fungi. Giant fire beetles could be found scurrying around the stone floors, and were often thrown together in a large cage to create naturally-powered lanterns.

Assistants

For quite some time, Arcturia had an illithid assistant who lived within her domain. She even went so far as to create a tentacle-themed private room for them near her own lab. However, after beheading her assist to study the psychic energy found within, she was forced to lure Ellix Gaspar from the arcane academy Dweomercore. As of the Year of Three Ships Sailing, 1492 DR, Ellix could be found wandering around Arcturiadoom in a state of befuddlement and stupor, after having displeased Arcturia.
Fire giants

The half-dozen or so fire giants that called this level home spent most of their time in the foundry. Several of them focused their efforts on the creation of the giant metal construct referred to as *Mecha-Hallaster*.
Experiments

Arcturia's domain was full of unique "creations", horrific creatures she had experimented upon in one manner or another. Among these abominations were a, ogre with the head of a carrion crawler, a two-headed rodent the size of a man, a number animated rusty swords that were animated into a humanoid form along with an umber hulk that had been *polymorphed* into a giant scorpion and forced to live within an enormous shoe.
* Guffaw the Stone Eater: One of Arcturia's experiments was a deep gnome named Guffaw, who had been altered by Arcturia to possess a voracious appetite for worked and carved stone. He felt wholly compelled to eat any such stone he encountered and had to limit to how much he could devour.

Death's Head Phalanx

This band of hobgoblins established a barracks and base camp within the south-eastern halls of Arcturiadoom sometime during the 15th century DR. Their leader, Doomcrown, kept his personal quarters in a nearby chamber. The clan also maintained several guard posts throughout the level, along with a training room and a large rallying area, used for mustering their ranks.
## History

Before Arcturia claimed this domain as her own it existed as part of the subterranean realm of the dwarves of Clan Melairkyn.

Sometime prior to 1492 DR, Emberosa and her fire giant kin came to Arcturiadoom on a mission to aid their efforts in dethroning the storm giants of Faerûn within the giants' ordning. They originally sought an ancient *rune of power* created some 40,000 years before the Second Sundering, which they believed was stolen by dwarves and taken to their domain beneath Mount Waterdeep.

During their excursion into Undermountain, the fire giants were accompanied by the Death's Head Phalanx band of hobgoblins, led by the Warlord known as Doomcrown.

Within the central hall of Arcturiadoom, the fire giants gathered scrap metal from Trobriand's Graveyard and began construction on an enormous magical-iron automaton called Mecha-Hallaster. This 100' (30.5 m) tall machination was the near-exact duplicate of Halaster himself, though by 1492 DR, it was still incomplete. The Mad Mage intended to use this colossus to combat the Walking Statues of Waterdeep when the time arrived to conquer the surface city.

## Appendix

### Notes

1. ↑ Based on the damage from 5e SRD
2. ↑ Canon material does not provide a year for the events described in *Waterdeep: Dragon Heist*, but Christopher Perkins answered a question via Twitter and stated the year was 1492 DR. Unless a canon source contradicts this assertion, this wiki will use 1492 DR for events related to this sourcebook and *Waterdeep: Dungeon of the Mad Mage* (which is referenced on pages 5 and 98 of *Dragon Heist*).
3. ↑ Canon material does not provide a year for the events described in *Waterdeep: Dragon Heist*, but Christopher Perkins answered a question via Twitter and stated the year was 1492 DR. Unless a canon source contradicts this assertion, this wiki will use 1492 DR for events related to this sourcebook and *Waterdeep: Dungeon of the Mad Mage* (which is referenced on pages 5 and 98 of *Dragon Heist*).

### References

1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 179. ISBN 978-0-7869-6626-4.
2. ↑ 2.0 2.1 2.2 2.3 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 182. ISBN 978-0-7869-6626-4.
3. ↑ 3.0 3.1 3.2 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 183. ISBN 978-0-7869-6626-4.
4. ↑ 4.0 4.1 4.2 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 180. ISBN 978-0-7869-6626-4.
5. ↑ Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 181. ISBN 978-0-7869-6626-4.
6. ↑ 6.0 6.1 6.2 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 185. ISBN 978-0-7869-6626-4.
7. ↑ 7.0 7.1 7.2 7.3 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 188. ISBN 978-0-7869-6626-4.
8. ↑ 8.0 8.1 8.2 8.3 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 187. ISBN 978-0-7869-6626-4.
9. ↑ 9.0 9.1 9.2 9.3 9.4 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 184. ISBN 978-0-7869-6626-4.
10. ↑ 10.0 10.1 10.2 10.3 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 189. ISBN 978-0-7869-6626-4.
11. ↑ 11.0 11.1 Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 186. ISBN 978-0-7869-6626-4.
12. ↑ Christopher Perkins (November 2018). *Waterdeep: Dungeon of the Mad Mage*. Edited by Jeremy Crawford. (Wizards of the Coast), p. 190. ISBN 978-0-7869-6626-4.

### Connections

Undermountain
The Largest Dungeon of the Forgotten Realms

**Upper Levels:** Dungeon Level • Arcane Chambers • Sargauth Level
**Sublevels:** Citadel of the Bloody Hand

**Deep Levels:** Twisted Caverns
**Sublevels:** Wyllowwood • Maddgoth's Castle • Dweomercore • Muiral's Gauntlet • Trobriand's Graveyard • **Arcturiadoom**

**Dark Levels:** Maze Level • Seadeeps
**Sublevels:** Lost Level • Slitherswamp • Troglodyte Warrens • Obstacle Course • Crystal Labyrinth • Vanrakdoom

**The Gauntlet Below:** Caverns of Ooze • Terminus Level • Mad Wizard's Lair
**Sublevels:** Runestone Caverns • Shadowdusk Hold