Two undercovers – one is turncoat and one lost his memory. They both betrayed the police force, they are friends but they are also enemies. The war between black and white has begun… Lung was an undercover. He returned to police force after cracking a case. But he soon resigned and joined the organization of gangster Old Chan. But he wasn’t treated well as both police and gangster consider him as a traitor. Jing was also an undercover being assigned to follow Old Chan. He reported the information to Sir Chau and ruined a drug dealing deal. Old Chan suspected that Lung was the rat. Jing rescued Lung from the tortures. Lung told him many the history when he was undercover that resonates Jing. They soon become close friends. Lung deiced to plan a robbery. He gathered Jing and two other guys from the organization. During the robbery, Jing shot a policeman and the booty was taken by the other two guys. Lung and Jing had a car accident while they were trying to escape. Jing got Amnesia. He was told by Lung that he is a gangster once he woke up. But later, he was kidnapped by Sir Chau’s team and told him that he’s a police. In the meanwhile, Lung was planning to get the booty back. Jing has to decide which side he’s taking.