Tyler, Nicholas Tse, a street-wise youth, has a brief, drunken encounter with Ah Jo, Cathy Chui, a lesbian undercover cop - as a result, she gets pregnant. Nine months later, Tyler is working as a bodyguard for his uncle and giving most of his wages to Ah Jo, who wants nothing to do with him. Tyler befriends Jack, Wu Bai, whose wife is the daughter of a triad boss; Jack`s father-in-law-is targeted by Brazilian criminals, and the friends find themselves on opposite sides in the ensuing mayhem.. The plot`s the least important element in veteran Hong Kong action director Tsui Hark`s return to his home base after making a couple of Jean-Claude Van Damme movies in Hollywood. The film`s just an excuse for almost non-stop and frenetically crazy action scenes, scenes which contain knowing references to the films of John Woo as well as to Hark`s earlier films. Nicholas Tse, a Hong Kong singer and Wu Bai, a Taiwanese rocker, give vigorous, physical performances as the battles rage in apartment buildings, in Kowloon`s railway station or behind the scenes at a rock concert - the climax involves the delivery of a baby in the middle of a ferocious gun battle. It`s all spectacularly done and, if you like this sort of thing, well worth a look.