In Macau, three men break into a house, shoot a French woman (Sylvie Testud) and kill her husband and two children. The woman's father, Francis Costello (Johnny Hallyday), arrives to visit his daughter who is now suffering from serious injuries. She is nevertheless able to tell her father that there were three shooters and that she shot one of the killers in the ear. At a hotel, Costello meets Kwai (Anthony Wong Chau-sang), Chu (Gordon Lam) and Fat Lok (Lam Suet), a trio of hitmen who are hired to murder the unfaithful wife of Triad crime boss George Fung (Simon Yam). After overhearing the murder in a hotel room, Costello reaches an unspoken agreement to walk away. Costello later tracks down Kwai's syndicate, hands them a stack of euros and his watch, and asks them to help him avenge his daughter's family's deaths. Before doing so though, he takes a Polaroid picture of each of the hitmen, and writes their names on the pictures so that he will not forget who they are. The four go to the apartment where the shooting occurred and work out what happened, the number of shooters and the weapons used.