The #1 New York Times bestselling author of the acclaimed Alex Delaware novels and the award-winning #1 international bestselling author of The Genius combine their extraordinary talents for one of the most unusual—and unnerving—thrillers of the year.

Detective Jacob Lev has awakened dazed and confused: it appears he picked up a woman the night before, but can’t remember anything about it. And then suddenly, she’s gone. Not long after, he’s dispatched to a murder scene in a house in the Hollywood hills. There is no body, only a head. And seared into a kitchen counter is a message: the Hebrew word for justice.

Lev is about to embark on an odyssey—through Los Angeles, London, and Prague, through the labyrinthine mysteries of a grotesque ancient legend, and most of all, through himself. All that he has believed to be true will be upended. And not only his world, but the world itself, will be changed.