The Shift Tome is a book of conjuration and summoning. It holds spells from across the ages, from as far back as the Dawn Era to the present day. Work on the tome began under Piranoth. In the Abyssal Release, it was plundered by forces under Baphomet. On his way to becoming a demon lord, Baphomet added to the book, twisting some of the writings so that the magic within the book comes out twisted.
The book ended up on Bal-Kriav in the Horgon Era. This came about after Gradorian agents, working with information from Dispater, sneaked into Baphomet's maze-hold Lyktion, making-off with the Shift Tome and many other riches.
The Shift Tome holds some very powerful spells that can get its user(s) in trouble. In the Horgon Era, using this tome, Gradorian wizards of Lod Stohl tried to summon a devil army from Dis. Tricked by Dispater, instead of summoning an army, Lod Stohl was summoned, "shifted" from its location on the world of Bal-Kriav to the faraway world named Dis. The abrupt disappearance of an entire city, left a great smoking rift called Ausul Raf.