Psychiatrist Ko Lap Yan is completely disheartened by the death of his wife, and had plans to quit his job and leave Hong Kong. Before he leaves, he encounters a psychopath murdering case 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, Yan decided not to leave and joined the forensic psychiatry branch. In his new job, Lap Yan meets his colleague Cheuk Wai Kiu and policewoman Lam Chung Yan. Lap Yan and Chung Yan quickly became friends, while Kiu developed feelings for him. The three get entangled in a subtle love triangle, each keeping their feelings inside. Lap Yan encounters a serial killer case and based on his analysis, it was very likely that the killer is someone he knows. Meanwhile, Lap Yan discovers his wife's death was not an accident.