Keung (Jackie Chan), a Hong Kong cop comes to New York to attend the wedding of his Uncle Bill (Bill Tung) who introduces his new wife to him down at his supermarket, which he owns and is in the process of selling to Elaine (Anita Mui). Uncle’s friend, Steven Lo, loans him a vintage automobile for the wedding. Later that night, a street gang starts a motorcycle race near Uncle Bill’s apartment. They are about to run over his friend’s car until Keung jumps down and stops them. He soon starts a rivalry with the street gang when he drives them away from the supermarket that they were robbing and vandalizing. When a member of the street gang named Angelo (Garvin Cross) gets involved in an illegal diamond deal gone bad and steals the diamonds, the small-time gangsters become the victims of a much larger criminal syndicate, and Keung agrees to help their leader, Tony (Marc Akerstream). Keung convinces the street gangsters to reform, then brings the big-time criminals to justice.