Former detective Shen Mo developed dissociative identity disorder after the trauma of his daughter's fall from a building three years ago. He split into a calm, logical "Detective personality" and a paranoid, vengeful "Avenger personality." To hide his condition, he poses as a private investigator and takes cases. But while investigating a serial corpse-burning case, he discovers that irises, his daughter's favorite flower, have appeared at every crime scene. Su Heng, a kindhearted library researcher and expert in ancient book cryptography, gets involved and gradually uncovers the truth sealed away in Shen Mo's memories: his daughter's death was no accident. As Shen Mo's "Avenger personality" begins to take control, he must choose between finding redemption with Su Heng's help and under the constraints of the law, or plunging into total darkness...
