A gruesome serial killer calling himself the Lamb of God is stalking the streets of New Orleans and leaving a trail of blood and terror, but city officials, still reeling from the effects of a devastating hurricane the year before and desperate to reboot the tourism business that is the lifeblood of the city, refuse to acknowledge that the murders are connected and deny homicide detective Sean Murphy the resources he needs for a proper investigation.

So Murphy sets out to stop the killer the best way he knows how, by getting inside the killer's head, by thinking the way the killer thinks, and by anticipating the killer's next move. But thinking like a madman is a dangerous game that can have unintended and deadly consequences.