Arkham Horror Mysteries

About the adventure

In The Thricefold Power, strange events ripple across Arkham in repeating patterns—triple omens, mirrored crimes, and witnesses who speak of seeing the same figure in three places at once. As investigators dig deeper, they uncover a hidden triad of influence: an ancient entity, its mortal adherents, and a ritual designed to fracture reality into overlapping aspects of itself. Each revelation peels back another layer of a conspiracy built on balance, sacrifice, and multiplicity. Designed for narrative-driven play, this book provides: A complete multi-session scenario centered on unraveling a three-part occult design New adversaries and mythos threats embodying divided forms and shared consciousness Optional player character backgrounds and abilities tied to forbidden knowledge Setting material that expands Arkham’s secret societies and esoteric traditions Blending investigation, moral dilemma, and escalating cosmic dread, The Thricefold Power challenges players to confront a truth that cannot be understood from a single perspective. In Arkham, power rarely stands alone—and when it comes in threes, the cost is never evenly divided.