This six volume collection is said to be the key to unlocking the forbidden knowledge of Nyarlathotep, a Great Old One, and contains instructions for summoning his twisted servants.
- Volume I: The Whispered Histories
- Volume II: The Vault's Schematics
- Volume III: The Rituals of Binding
- Volume IV: The Tongues of Madness
- Volume V: The Grimoire of Stars
- Volume VI: The Apocalypse Manuscript