Martin Smith and John Becker: bestselling authors with ordinary names and extraordinary minds. Rivals since childhood, they are natives of the northern California town of Twilight Falls, and famous for their uncanny similarity in both physical manner and literary voice. When one of them ends up dead at the other's home, an investigation is launched into their dark past, revealing a series of troubling stories from their childhood, adolescence and careers, throughout which pervades a sinister presence, an authorial entity with roots beyond our time or dimension - an entity with far-reaching designs.