On Bai Yuchen's journey to avenge his mother and sister, a policeman regarded him as a suspect in the suicide case of a female star and brought him to the police station. When the two spent time together, the policeman found that he fell in love with the madman. He kept brainwashing himself until the lunatic committed many crimes, and the policeman chose to let go.
Concept: Sin and darkness are symbols of those "monsters".