Inspector Eddie Chan (Jackie Chan) of the Organized Crime and Triad Bureau, is suffering from emotional stress after shooting several men in self-defense. Chan is made to undergo psychological evaluation for his condition with the department doctor (Pan Lingling). The incident was only 2 days ago when armed gunmen opened fire in a busy and crowded market, endangering women and children. Chan put his own life at risk to kill the 4 gunmen and safe many civilian lives in the process. The Psychiatrist says that Chan is either afraid of injuring civilians with his actions, injuring himself, or has a feeling of remorse after killing the perpetrators.Wong is wanted by brotherhood of Ng Kwok-Wah (Chung Fat), Ng Kwok-Yan (Ken Lo), Simon Ting (Wan Fat) and Hung Ting-Bong (Kent Cheng) (Hung is also a detective), Yen Chi-Sheng (Wan Seung-Lam), who have sworn a blood oath to be partners. The brotherhood vows to fight and erase the corrupt businessman Wong. Wong approaches Superintendent Cheung (William Tuan) with a suspicion of threat to his life. Chan is assigned to protect Wong Yat-Fei (Law Kar-Ying).Wong is a wealthy real estate developer. He had the permit to build luxury apartments on a piece of land he purchased for cheap in 1967. But since the project is not selling, he decides to split each apartment into 4 units, so sell it to the masses. The changes will require 2 families to share a bathroom and a kitchen. Wong is not paying his workers on time either. Wong claims that the dispute is between the contractors and the laborers, and that he is paying the contractors as per the contract.On his way back home, Wong and his wife (Puishan Au-Yeung) are kidnapped by the brotherhood. Hung supervises the kidnapping over a mobile phone. Wong manages to call Chan who pursues Wong's car, but the kidnappers use other cars to crash Chan. Chan calls the central control unit who dispatch traffic cops. The kidnappers ram through the traffic police bikes, injuring them gravely. Chan abandons his pursuit to take one injured traffic cop to the hospital, while the other dies. Chan feels he is responsible for the life of his colleagues in the line of duty. Hung puts Wong into a boat to be shipped to Taiwan. His wife is released with a ransom demand of USD 60 million.Superintendent Cheung launches a massive manhunt to search for the people behind Wong's kidnapping. Hung was the detective who solved the case of Wong's first kidnapping and is brought in to the task-force. The task-force intercepts several calls to Mrs Wong from the kidnappers. But Hung conceals that one of those calls came from Taiwan. Based on the instructions, Mrs Wong withdraws USD 60 million and starts to deposit it in 10 different accounts of a Taiwan based bank. Once the account numbers are known, Chan asks Mrs Wong to stop the transfer midway, after only USD 30 million are deposited. Chan argues that if the full amount is transferred, they may never see Wong again.The accounts are in the name of 4 account holders in Taiwan. Hung volunteers to go to Taiwan and Chan is sent to assist him. One of the account holders is Simon Ting. Captain Ko (Blackie Ko) from the Taiwan police is assigned to help Hung and Chan. Due to lack of any diplomatic relations between Hong Kong and Taiwan, Chan and Hung are in Taiwan in unofficial capacity only.Ko leads a raid on a location where Simon was spotted. Chan follows Ko secretly. The raid manages to kill many gangsters but Simon escapes. Chan sees this and pursues Simon and fights off his goons. Hung tries his best to stop Chan from successfully pursuing Simon. Chan almost captures Simon but Hung throws a bamboo log at Chan to throw him off, allowing Simon to escape. When it is clear that Simon cannot escape, Hung kills him. Just before that Chan had seen Simon threatening to expose Hung if he didn't help him.Hung and Chan are deported to Hong Kong. Chan requisitions Hung's cell phone records, but Hung is informed, and he orders all his cell phone records to be deleted by the telephone company. Before the records are deleted, Chan manages to get one number and one area code 369 from the database.Chan visits a brothel and meets Lara (Christine Ng), who is a prostitute and Hung's mistress. Hung is informed when Chan arrives to question Lara. Before Lara can identify Simon as Hung's partner, Hung arrives, gets Lara separated from Chan by distracting him. Hung bribes Lara with a house in Australia and she agrees to lie to Chan. The number tracks to Euro Boy, an informer of Hung. Chan arrests Euro Boy. Hung arrives and hits Euro Boy on the head with a bottle, pretending to be livid. Hung then argues that Euro Boy be taken to the hospital for treatment.Meanwhile, a raid on Simon's Hong Kong's office reveals the photo of a freighter where Wong might be held kidnapped at sea. Once again, Chan finds that the freighter is empty. He writes "Hung kidnapped Wong" in a wall in the cargo hold. This was the place where Wong was held captive. When Hung sees it, he tries to erase it, but he didn't know that Chan was watching. Hung then drops Chan deep into the cargo hold, assuming he died. Hung shoots himself with Chan's gun and goes to the ship's surface and claims that Chan shot him, and he killed Chan in self-defense.As Hung is taken to the hospital, Chan manages to escape the cargo hold and contact Cheung. Meanwhile, Hung authorizes the transfer of the remaining USD 30 million to the Taiwan bank accounts. As Hung finds that Chan has escaped the cargo hold, he disappears. Chan searches for clues about where he could be. Chan visits Kowloon as that's where Hung had a lot of receipts from. Eating at a local street food vendor, he realizes that 369 refers to an address Shanghai 369. But Chan is noticed by Hung's partners and attacked. One by one, Chan kills all of Hung's partners. Chan then traps Hung inside the building, and attacks. Chan kills all the men protecting Hung and confronts him, who says that pension is not good enough to retire. Hung refuses to divulge Wong's location. The building catches fire as the gas main blows. As the building is evacuated, Chan notices that a kid is trapped inside his home. Chan goes to rescue the kid, as Hung tries to escape. But Hung falls through the weak floors and is gravely injured. Still, Chan comes to rescue Hung, and Hung reveals Wong's location.Chan manages to escape with the boy, before the building blows up. Wong is rescued and reunited with his wife.