Don Lee (Nick Cheung), a police detective in Kowloon whose reliance on informants leaves him struggling with a guilty conscience.

Lee's previous stool pigeon's cover was blown and was attacked, leading him paranoid and driven from his wife and home.

Lee recruits a street racer named Ghost (Nicholas Tse) as his latest stool pigeon who is assigned to infiltrate a gang led by the notorious armed robber Barbarian (Lu Yi).

Ghost accepts Lee's offer so he can rescue his sister from a life of prostitution as well as help his father's one-million dollar debt.

Lee also has personal problems of his own, as wife Cher (Miao Pu) who he is separated with tried to commit suicide a few months previously and has since had amnesia.

[7] Dante stated that he "felt the pressure when I was working on the new movie because The Beast Stalker did so well and received a lot of positive feedback.

As if worried about the audience's attention span for drama, action scenes are intermittently inserted throughout but they don't build to one big momentum.