香港当红舞男Jackie（张学友 饰）与扫黄组组长David（林俊贤 饰）结怨很深。David多次派人扫Jackie的场子都遭失败，怀恨在心。扫黄组新调来的小珍（张曼玉 饰）能力超群，将鸭店一网打尽，连Jackie的店也难以幸免。Jackie为了替兄弟们出口气，决定扮作患有绝症的画家去接近小珍，找机会报复，谁料……
The crooks in London know how it works. No one carries guns and no one resists the police. Then a new gang appears that go one better. They dress as police and steal from the crooks. This upset's the natural order of the police/criminal relationship and the police and the crooks join forces to catch the IPOs (Impersonating Police Officers), including an armored car robbery in which the police must help the gangs to set a trap.
一名18岁的少年通过网络犯罪获得了数百万的赃款，不料惹到了无情的犯罪团伙，他必须面对自己的错误，为保护他所爱的人而战，以免为时过晚。
