Once the victim of the prolific Flower Cannibal, Simon is a criminal psychologist who takes on only the darkest cases with the worst perpetrators imaginable. Jian Yiao, an observant young woman, starts working for Simon and becomes his assistant, following him down the dark path of the criminal mind. However, the Flower Cannibal is not finished with Simon, and they soon learn that there is more to the cases they take on than they could have ever imagined.