Nicholas Tse manages to get a woman pregnant after a one night stand. In order to earn money, Nicholas joins a unlicensed bodyguard group. He then encounters Wu Bai, a killer, at a store. In fact, Wu Bai has fallen out with his Spanish buddies. His means of revenge is murder. When Nicholas Tse spots Wu Bai at a murder scene, they recognize eachother and Wu Bai does not kill Tse. Not realizing they hardly know eachother, the cops want Tse to reveal Wu Bai's identity. All this lead to the last 40 minutes of tension: jumping, shooting, explosions, and everyone trying to find Wu Bai but only getting killed. Oh yeah, there's also a concert with an audience of 10,000 people.