Chinese detective Zhang Tiezhu (played by Danny Lee) worked hard for more than ten years to get the position of detective. He hates evil and hates flattery. He has many frictions with the new inspector Luo Sir. He worked hard to solve the case, but was made difficult by the latter. On the other hand, the gangster "Judge" (played by Shing Kui-an) bought guns and planned a big operation. The car thief Wei Zai (played by Stephen Chow) was taken in as an external assistant by the judge and provided with a car for crime. The judge and his men Crazy Bull (played by Huang Guangliang) and Chicken Wing (played by Ho Ka-kui) robbed a gambling den. On the same day, Wei Zai was arrested and imprisoned by Zhang Tiezhu on suspicion of stealing a car. When the gambling den incident happened, Luo Sir identified Wei Zai as a suspect despite Zhang Tiezhu's testimony, which made Zhang and Wei Zai very dissatisfied. Zhang Tiezhu released Wei Zai and asked Wei Zai to cooperate in arresting the judge and his gang. The judges' gang, who bought weapons, became more powerful and more arrogant. They fought with other gangs in the streets. Wei Zai was involved in a murder case and had to cooperate with Zhang Tiezhu. The police and the thief finally started to cooperate...