Reckless police inspector Sai Gau (Zhang Jin) is on a mission to crack down on criminal Shing's (Shawn Yue) gold smuggling scheme, yet fails to arrest him. As Sai Gau continues his manhunt, he discovers Shing's involvement with triad boss Blackie (Yasuaki Kurata), who hides on a casino cruise ship on the high seas. Shing has been involved in a power struggle within the smuggling ring, and is forced to kill his adopted father. He also loses his share of gold smuggling to Blackie. To get even, Shing appears on the cruise, while Sai Gau is there to hunt for him.

A Hong Kong cop named Kit busts a major gangster only to find his cover blown and his main witness gone. The gangster, in retaliation, has him kidnapped and put in a Thai jail with a false criminal identity. Lowly prison guard Chai, with his extraordinary fighting skills, guards Kit and prevents his escape. The prison guard’s daughter suffers from a rare form of leukemia and Kit is the only donor who can save her. The prison guard discovers Kit’s real identity and helps him to escape in return for his agreeing to save his daughter. Together, Kit and Chai must face and take down the gangster and his minions.