Cheung Yat-pang, Cantonese native whom recently returned from France to Nanjing after further studies, has been appointed by the Chinese government to be the first Commissioner of the opium trade ban. He accompanies his wife, So-so, to Shanghai to outlaw illegal opium trade, but on the way, a young boy tells him about the city's corrupt police force colluding with drug lords. Shanghai police commissioner Ngai Kwan organizes a welcome banquet for Cheung, where Ngai subtely theatens and bribes Cheung, who angrily walks out the party after seeing many officials smoking opium and declares he would mercilessly crack down any drug user or dealer. Cheung receives intel about a drug trade taking place Zhabei brick mine and leads a raid there, only to realize it was a scheme planned by Ngai to trick him. Later, Cheung discovers one of his subordinates, Shantung Cat is addicted to opium and dismisses him, but Shantung Cat convinces Cheung he is his only loyal and only non-corrupt subordinate, and the two work together to confiscate and burn illegal opium, which angers drug lord Paul Tai, who retaliates by instructing Ngai to kill attack the pregnant So-so, causing a miscarriage. Furious, Cheung publicly declares Tai a killer. Since many opium store owners had their goods confiscated by Cheung, Tai suggests them to sell packaged cocaine, which is overheard by Cheung's newly assigned assistant, Jean Wu, who informs Cheung about Tai's drug base in Jiugong Mountains. Cheung raids the base with Jean and Shantung Cat, successfully killing Tai's henchmen and destroying the drugs after engaging in a major gunfight. However, Cheung is later ambushed by Ngai's killers one night, where So-so is killed, while Jean was abducted by Tai and Ngai to interrogate her, driving her to suicide. Ngai abductes Cheung and injects him with drugs, forcibly taking a photo of Cheung smoking opium which makes it to the newspaper headline. Shantung, armed with a machine gun, shoots up the police station and holds Ngai hostage while rescuing Cheung, but Shantung Cat is captured while fleeing. Before being killed, Shantung Cat manages to manipulate Tai into suspecting Ngai. Cheung then lures Tai and Ngai to a cinema, where Cheung shows edited footage of Tai taking a shipment of cocaine for himself, which angers Ngai, who attempts to shoot Tai, but was killed by the latter. When Tai's henchmen attempt to kill the cinema audience to rid any witnesses, Cheung kills his henchmen while knocking out Tai, who survives. When Cheung boards a train back to Guangzhou, General Lee bids farewell before shooting Cheung dead, stating he was born at the wrong time. In the end, it is reported to the public that Cheung committed suicide for fear of his crimes, while Tai is set free without any charges.
Cast
Andy Lau as Cheung Yat-pang, the main protagonist, a Nanjing government investigator from Canton who studied abroad in France and previously worked for the Republic of China Military Academy.
Damian Lau as Paul Tai, the main antagonist, a Shanghai drug lord who poses as a philanthropist on the surface.
Cherie Chan as So-so, Cheung Yat-pang's wife
Ku Pao-ming as Ngai Kwan, the corrupt police commissioner of the Shanghai police force who colludes with Tai.
Chin Shih-chieh as Shantung Cat, Cheung Yat-pang's assistant who is addicted to opium.
