When the Ronin Gang robs an armored car, three cops — Chan, Fong and Wai — go on the warpath. Each has a personal interest in bringing down Ronin leader Tien: he killed Chan's fiancée, humiliated Fong and kidnapped Wai's brother.
Choi San-keung (Nick Cheung), a taxi driver who perpetually lacks sleep, thus endangering anyone who sets foot in his taxi. One passenger is psychiatrist Dr. Man (Terrance Lau), who survives the taxi ride and offers to help Choi. The offer is refused, but Choi later becomes Dr. Man’s involuntary patient after a particularly egregious night of driving. Dr. Man has his own personal issues: his motto is “I think a doctor should do more than prescribe meds,” which means a doctor should also investigate his patients secretly in defiance of common sense and hospital protocol. In a parallel to Choi San-keung, Dr. Man also has sleeping issues. He suffers from disturbing dreams of his deceased mother, which hints at a secret involving his father (Ben Yuen), and perhaps some repressed memories. Both Dr. Man and Choi San-keung are characters tortured by dark pasts, and acknowledging these memories is key to solving their problems in the present.
An ultraviolent cops vs. gangsters bloodbath leaves casualties on both sides. Twenty years later, surviving team member Madam Fong leads a new squad in pursuit of reckless young anarchists terrorizing Macao.
An operation in Thailand against a notorious drug lord changes the destiny of a Hong Kong Police Department narcotic team. Five years later, a drug dealing brings them together again.
A poor young man is wrongly charged with drug trafficking after being deceived. An ex-prosecutor investigates the case, uncovers a corrupt lawyer team's scheme, and restores justice despite obstruction from evil forces.