Dweomercore

Dweomercore was the ninth level of Undermountain. An arcane academy founded by Halaster Blackcloak himself, as of 1492 DR, it was being run by an arcanaloth and a night hag by the name of Wormriddle.

Exits
As of 1492 DR, the following ways could be used to leave Dweomercore:
 * A tunnel up a level to Slitherswamp, in the north–west corner.
 * A pit in the middle of the level that dropped straight down to level 10, Muiral's Gauntlet.
 * An archgate in the south part of this level leading to level 4, the Twisted Caverns.

Inhabitants

 * Arcanaloth: An ally of the Mad Mage, it employed nycaloths and mezzoloths, and granted safe passage in exchange for magic items or assassination of the rampaging bone devil.
 * Wormriddle: Proud commander of four flesh golems, she was ready to offer spells in exchange for souls and wore a mummified kitten's head, because of her fear of felines, from cats to Tabaxi.

Vile Students

 * Spite Harrowdale, a Rashemi human archmage in the guise of a twelve-year old boy, with an oni companion.
 * Cephalossk, a lonely mind flayer arcanist with a hatred for Spite Harrowdale.
 * Nylas Jowd, a Thayan mage already enrolled in the Red Wizards of Thay, with two invisible will-o'-wisp companions.
 * The Horned Sisters, Turbulence and Violence, were tiefling mage sisters who tried to join the Arcane Brotherhood in Luskan and were denied. After staying in Skullport for a few years, they ended up here.
 * Elan Tanor'thal, a drow mage whose house ran a slave-trading business in Skullport but was driven out by the Xanathar's Thieves' Guild.