Chan Wing Yan, a young police officer, has been sent undercover as a mole in the local mafia. Lau Kin Ming, a young mafia member, infiltrates the police force. Years later, their older counterparts, Chen Wing Yan and Inspector Lau Kin Ming, respectively, race against time to expose the mole within their midst.

Mob assassin Jeffrey is no ordinary hired gun; the best in his business, he views his chosen profession as a calling rather than simply a job. So, when beautiful nightclub chanteuse Jennie is blinded in the crossfire of his most recent hit, Jeffrey chooses to retire after one last job to pay for his unintended victim's sight-restoring ...

In this prequel to the original, a bloody power struggle among the Triads coincides with the 1997 handover of Hong Kong, setting up the events of the first film.

While Yeung Kam Wing is trying to remove all connections between the mob and him, his actions are being carefully observed by Lau Kin Ming, who bears a personal grudge against him.

A strange investigation doesn’t erase the regrets of a grieving woman cop. Every four years, the past catches up with her. Every four years this woman is very afraid. Her fear is such that she feels it could kill her because in her dreams reality begins.