The Mithardir Quest is one of the alignment-based quests in dNetHack. It is one of the random variants of the Chaos Quest. As is typically the case for dNetHack's alignment quests, it is divided into roughly three parts (though in this case there is a town on top).
The level of the main dungeon containing the portal to the Mithardir Quest will have the following layout:
... ..........~~~~~~~~~~~~~~~~~~~~~~~~~....... ...
-<. ..........~~~~~~~~~~~~~~~~~~~~~....... .>-
--. ............~~~~~~~~~~~~~~~~........ .--
Elshava is a cluster of random shops surrounded by water. The shopkeepers sell a variety of useful gear, including items that can't be found anywhere else in the game. All types of shop can also be paid to ID tiles and slabs recovered from Mithardir.
The portal to the next level is somewhere in the shallow water outside the town. You can use any portal detection method to find it (including wandering around the shallows until you stumble through it) or you can pay one of the shopkeepers to reveal it.
The Mithardir Wastes are a series of three levels consisting of white dust and random rock formations. Dust storms are frequent, producing blinding clouds. The largest of these clouds may inflict deadly illness, so they should be avoided. A small amount of tiles can be found scattered randomly across the level (but no slabs).
These levels are connected by portals. You can use any portal detection method to find the next portal, and the portals will also be revealed if you get within 2 squares of them. The last of these levels has a round tower in the center, which contains the downstairs. The tower does not have a door, and must be dug or teleported into.
The Last Spire is a series of three fixed-layout levels. The mid-boss of the branch, the First Wraithworm, is found on the second level along with the Second Key of Chaos. The first slab is found on the third level.
These levels are connected by a mixture of portals and staircases, typically found behind hidden doors (though the portal in the First Wraithworm's room is positioned randomly).
The Mithardir Catacombs is a set of three random-layout levels. The boss of the branch, the Aspect of The Silence, is found on the lowest level, along with the second and third slabs. Tiles can be found in closets around the level, along with on Alabaster mummies.
Alabaster mummies can be found on these levels, tied to a specific syllable of power. The syllable is randomly determined but will modify the mummy's attack routine in accordance with the syllable chosen. The syllable will drop on death.
A variety of unique treasure can be recovered from this branch:
- Living Armor: The shops in Elshava may sell living armor/giant sea anemone and/or barnacle armor/giant shell armor. These armors automatically attack nearby enemies when worn.
- Living Masks: The shops in Elshava may sell these, which take up your face slot and grant magical breathing while worn.
- Ceramic Tiles: These are found throughout the quest. Each tile bears one of six magic syllables. Each type of syllable grants a temporary bonus and (lesser) permanent bonus when read.
- Slabs: These are the "artifacts" of the quest. The first is found after the mid-boss, and the second and third are found on the last level of the quest. Each slab bears a different Word of Creation (the order that the Words are generated in is random). When read, each Word grants a passive bonus and an activated power.
Mithardir is from Dungeons and Dragons. The upper parts of the quest (Elshava through the Last Spire) are based on the adventure "The Ruins of Pelon" from Dead Gods, by Monte Cook. The lower part of the level is (very) loosely based on the ruins of Shom, from 4th edition D&D.