The world just learned that monsters and demons are real—but agent Kal Hakala is in St. Louis to battle an evil force not even the BSI could have imagined.

The Bureau of Supernatural Investigations has managed to keep the existence of magic and monsters a secret. Until now. Recent events in Omaha—a.k.a. agent Kal Hakala's latest battle with the World Under—has let the demonic cat out of the bag. Now, sidelined as an Agent, Kal serves as the BSI's public face, charming talk show hosts and training new recruits. But the World Under never rests, and it's not long before Kal is needed back in the field.

A malevolent spirit occupies St. Louis's Quint Building, and the team sent to handle it disappears after their leader is driven to suicide. The BSI has no choice but to send in Kal and his team. As each of Kal's team members is isolated and dumped into his or her private hell, Kal begins to wonder if he hasn't finally met his match: the most powerful, malevolent force in the World Under.