Necronomicon
Here are all the books by Simon about the Necronomicon:Necronomicon Spellbook (an instruction manual of how to use the Necronomicon's spells safely)Dead Names: The Dark History of the NecronomiconGates of the Necronomicon'' (a book explaining the Walking of the Seven Gates, a long and complicated ritual that all first-time users of the Necronomicon must perform)