Infernal Affairs II (2003)

Undercover Las Vegas police officer Vincent Downs, who has a lot of enemies, is caught in a high stakes web of corrupt cops and the mob-controlled casino underground. When a heist goes wrong, a crew of homicidal gangsters kidnap Downs’ teenage son T. In one sleepless night, Downs will have to rescue his son, evade an internal affairs investigation, and bring the kidnappers to justice.

Ben Archer, an ex-mob enforcer, seeks revenge against a ruthless Chinese kingpin responsible for his wife's brutal murder. When Archer joins forces with his old underworld friends, an all-out war is waged against the Chinese Triad.

With personal crises and age weighing in on them, Riggs and Murtaugh must contend with deadly Chinese triads trying to free their former leaders from prison and onto American soil.

After losing an election to become chairman of the Wo Lin Shing triad, a gang leader lashes out and tries to seize the dragon-head baton, the official symbol of a chairman's authority.

Two brothers, on either side of the law, face off over organized crime in Brooklyn during the 1970s.

Mid-level gangster Wah falls in love with his beautiful cousin, but must also continue to protect his volatile partner-in-crime and friend, Fly.

A financial tycoon, once a triad member, tries to eradicate the drug market while an old accomplice aims to be Hong Kong's first drug lord.

A Chicago cop is caught in the middle of a gang war while his own comrades shun him because he wants to take an irresponsible cop down.

A career-long undercover Hong Kong cop is sent to Mainland China when his former protégé becomes the primary suspect in a murder.

Ko Chow is an undercover cop who is under pressure from all sides. His boss, Inspector Lau, wants him to infiltrate a gang of ruthless jewel thieves; his girlfriend wants him to commit to marriage or she will leave Hong Kong with another lover; and he is being pursued by other cops who are unaware that he is a colleague. Chow would rather quit the force, feeling guilty about betraying gang members who have become his friends.