Fellglow Keep

 is a location in The Elder Scrolls V: Skyrim. Led by Orinthir, mages that left The College of Winterhold fled to this location to practice forbidden experiments. Urag gro-Shub sends the Dragonborn here in search of three books to help he or she research the strange orb found at Saarthal. Throughout the location, several Novice Conjurers, Novice Ice Mages, Novice Fire Mages, Novice Storm Mages, and Novice Necromancers are found and battled. The mages keep Vampire test subjects caged in the halls below, using them to perform cruel surgical experiments, as well as using them as the targets for practicing Destruction spells.

Searching for the books, the Dragoborn discovers that the other mages turned on Orinthir, caging him. If the player frees him, he fights alongside he or she as a Companion. He uses the spells Firebolt and Familiar. He reveals that a mage known simply as The Caller, imprisoned him after stealing the books.