Psychiatrist Ko Lap-Yan is completely disheartened by the death of his wife, and has plans to quit his job and leave Hong Kong. Before he leaves, he encounters a murder case committed by a psychopath and investigates the case with forensic psychiatrist Leung Kai-Wing, thereby regaining his passion for psychiatry. With the advice from his good friend Lin Chi-Sam, Lap-Yan decides to not leave and joins the forensic psychiatry branch. Together with new friends and new colleagues, they assist the criminal investigation department in solving cases.