Mayor Otto Finch and demonologist Dr. Beatrix Brighton have followed a trail of horror deep into the mountain tunnels beneath Berlin, New Hampshire. Thirty years of twisted experiments line their path—a grotesque gallery of John Lavoie's madness made flesh.

But the tunnels hold more than just a missing child. They contain the truth about what Marie Lavoie has been feeding her transformed son all these years. About the spell that went wrong—or perhaps went exactly as planned. About the real reason John was banished to the woods three decades ago.

In the suffocating darkness beneath Jericho Mountain, Otto and Dr. Brighton will face the full horror of what John has become. Armed with nothing but a blood-stained hatchet and decades of experience battling evil, they must navigate a labyrinth designed by a predator who knows every shadow, every sound, every way to kill.