Hahou Mo, a martial arts master and former police instructor, is serving time for accidentally killing an opponent. When a ruthless killer begins targeting top martial artists, Hahou offers his assistance to the police in exchange for his freedom. Detective Luk Yuen-sum reluctantly agrees and releases Hahou to track down the murderer who seems to be following a pattern, challenging and killing skilled martial artists in their respective disciplines.

As Hahou and Detective Luk delve deeper into the investigation, they discover that the killer shares a similar background in martial arts. Each murder scene offers clues that suggest a deeper, more personal motivation behind the killings. Their quest takes them through a series of intense confrontations and tests of skill, bringing Hahou face-to-face with his own past and the values he holds dear. Suspense builds as they race against time to stop the killer before he claims his next victim, leading to a climactic showdown where both justice and redemption hang in the balance.