On the streets of downtown Hong Kong, a money escort car was hijacked by Cao Nan (Hu Jun), a felon with a long criminal record. Senior Inspector Lu Mingzhe (Andy Lau) of the Serious Crime Unit led a team to the scene and had a fierce gunfight with Cao Nan and his gang. Unexpectedly, at the critical moment, a car suddenly appeared and disrupted the situation. Cao Nan took the opportunity to escape, and the owner of the car, Tao Chengbang (Lin Jiadong), was invited to the police station by the police. Tao and Mingzhe are old classmates, and later they became gangsters. He had just been released from prison not long before the accident. Mingzhe and Chengbang's girlfriend Yan Bing (Yao Chen) did not believe that he had nothing to do with Cao Nan, and the arrogant Cao Nan played tricks on the police five times. In order to catch this cunning and fierce opponent, Mingzhe decided to arrange an insider to infiltrate the other party, but he suffered a tragic setback. Standing at the crossroads of life, Tao Chengbang's choice became the key to the battle. As the storm intensified, the boundaries between good and evil were completely blurred...