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.

A Hong Kong cop is struggling for his survival in the underground world, a place filled with criminals and low life people like moss in rotting hell.

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.

Feng (Shawn Yue) is a former undercover cop whose post-assignment life has begun to rapidly disintegrate. Feng and former triad brother Fai (Sam Lee of Gen-X Cops) are caught using cocaine, and the ensuing melee leaves a police detective dead, with Fai fingered as the culprit. Fai must go on the run, but he no longer trusts Feng, who he believes may be leveraging their brotherhood for advancement in the police ranks.

Ryo Narushima is a student who has served prison time for killing his parents. Once he is released, he trains to become a professional kick-boxer.

A Macao police officer's bachelor life is interrupted by the daughter he never knew he fathered.

When the Hong Kong government enacts a ban on smoking cigarettes indoors, hard-core smokers are driven outside and a budding romance develops between two co-workers.

Three young martial arts masters emerge from the back streets of Hong Kong to help the powerless fight injustice.

When Triad leader Hung considers leaving the world of the gangsters, a brutal war begins in the world of jiang-hu. Meanwhile, an internal conflict begins between Hung and his best man, Left-Hand.

Spoof of the Hong Kong Blockbuster Infernal Affairs, the film is based on a bizarre and nonsense war between the police and the triads. Lek Sir sends Keung, Yan, and Fatty undercover inside Sam's garage to get evidence of any crime Sam has committed, so Lek can win back the heart of Sam's wife Mary.