A French chef and former assassin wrestles with his failing memory while fighting to avenge the murder of his daughter's family in Hong Kong in director Johnny To's stylish, action-packed meditation on the true nature of revenge. Her Chinese husband and their two young children brutally gunned down during a gangland hit, a mortally wounded French woman clings to life in a Hong Kong hospital. Upon arriving at his daughter's bedside, the shooting victim's father, Costello (Johnny Hallyday), vows to put the triggermen in the ground despite the vehement objections of police investigating the case. Before Costello became a cook, he too was a killer, but these days his past is just a distant blur. However, when Costello happens across a trio of hitmen (Anthony Wong, Lam Ka-tung, and Lam Suet) with the resources to strike back at his daughter's attackers, his killer instinct returns, and he begs their arrogant boss, Fung (Simon Yam), to help him seek revenge. As the operation gets under way, Fung and his men discover that Costello was once much more than a humble cook, but that his rapidly fading memory now makes him a vulnerable target to anyone who knows the secret to his treacherous past.
