Sammo Hung plays a cop on the trail of drug dealers. Customs officer Yuen Biao is investigating the same gang. Sammo's new partner is eager-beaver Takeshi Kaneshiro. Despite each having their own ideas on how best to proceed, they are teamed together and must put aside their differences in order to crack the case. Romance, plot twists, comedic asides, and, of course, plenty of fights bring the film to a climatic and bruising conclusion.