The whole town is waiting for the "flood dragon" to transform into a true dragon, yet no one realizes someone is waiting for a sacrifice! Rain pours relentlessly for seven days, and strange deaths occur one after another… Taoist Zhang Buping arrives in Longkou Town and discovers that every victim bears an ominous "Fallen Dragon Claw" mark. Is this the fulfillment of a thousand-year-old legend, or the perfect crime of killing in the name of a god?