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 Piamauza 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, Piamauza wizards of Lod Stohl tried to a devil army from Dis. This was to be an army of lowly spine devils but instead the wizards were tricked by Dispater. Instead of summoning an army, Lod Stohl was summoned, "shifted" from Bal-Kriav to one of Hells worlds. The abrupt disappearance of Lod Stohl left a great smoking rift called Ausul Raf.