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 with Piranoth, and when he abandoned the realm of his creation, Piranoths Steps, to the demons, it fell into the hands of one of his garrison commanders. This garrison commander of the remote outpost of Lyktion was a twisted, depraved warmonger named Baphomet. At the time, Baphomet was already half corrupted and warped by the chaos creeping across a realm that would become better known as the Abyss. In the Demon Spawn War, Baphomet used the Shift Tome to move his forces across vast distances.
The book ended up on Bal-Kriav in the Horgon Era. This came about after Piamauza agents, working with information from Dispater, snuck into Baphomet's maze-hold Lyktion and absconded with it.
The Shift Tome holds some very powerful spells that can get its user(s) in trouble. In the Horgon Era, Piamauza wizards of Lod Stohl tried to use the book to summon an army from the Hells world 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 from Bal-Kriav caused a split in the earth to open up under where it once was, creating a smoking rift called Ausul Raf.