In this third Police Story movie, Hong Kong 'Supercop', Inspector Chan Ka-Kui (Jackie Chan) is sent on a secret mission to mainland China where he is introduced to the military police force's Interpol director, Jessica Yang (Michelle Yeoh), who briefs him on his assignment.Ka-Kui has been selected by RHKP (Royal Hong Kong Police) Chief Superintendent Y.K. Chen (Philip Chan) and "Uncle" Bill Wong, RHKP Senior Superintendent (Bill Tung). Bill & Chen team up to pretend that this is a tough assignment, and that Bill doesn't want Ka-Kui to go. But Ka-Kui wants to accept the mission as he is the most qualified in Hong Kong Police to take on an assignment of this complexity and danger. Bill reluctantly accepts.
Ka-Kui tells his girlfriend that he is going for a special training where he will not be contactable.The target of the mission is a drug lord named Chaibat (Kenneth Tsang). Chaibat is responsible for smuggling drugs into Hong Kong using human couriers who carry the drugs in their bodies in condoms filled with drugs. Arresting Chaibat would reduce the flow of drugs by half.
Ka-Kui is made to undergo training for this special assignment. He is assigned the identity of Lin Fu-Seng, Age 32, a manufacturer at the Foshan Fifth National Machine Factory. He lives in the Juanyao village with a mother and a sister. His father was killed in a plane crash in 1978. He is made to take photographs in local clothes to prove his identity.In order to infiltrate Chaibat's Triad organization, the plan is to get close to Chaibat's henchman Panther (Yuen Wah), who is being held in a Chinese prison labor camp in Canton. Ka-Kui, posing as a petty criminal, is able to help Panther escape with the aid of Chinese military police, who eliminate Panther's men in the prison.
Panther then meets up with some of his other men, and Ka-Kui helps them escape to Hong Kong in exchange for $50,000.En route to Hong Kong, Ka-Kui, along with Panther and his men pass through the supposed home-village of Ka-Kui's undercover role. Panther insists that Ka-Kui visit his family there. Realizing he does not actually know anyone in the village, Ka-Kui is apprehensive but is pleasantly relieved to be greeted by undercover military police posing as his family, with Yang posing as his sister. Yang and the Chinese military police help them win Panther's trust by faking the murder of a local policeman, who had identified Panther in the village, by Yang.
Panther agrees to let Yang come with him to Hong Kong, as she pretends that she would be executed in China for helping Panther escape.After arriving in Hong Kong, Ka-Kui, Yang and Panther go to Chaibat's luxurious hide out. Ka-Kui and Yang succeed in winning Chaibat's trust, especially after helping his men destroy a fortified drug production lab in Thailand, somewhere in the Golden Triangle, when Chaibat betrays a number of other drug lords who are conducting a heroin deal with him.
Chaibat takes Ka-Kui and Yang with him to a big opium grower's fortified compound in the Golden Triangle military camp of Thailand, for a meeting of big-time heroin traffickers. The Thai supplier is refusing to sell any more opium to Chaibat as he hasn't paid for the previous shipment. All his share has been allocated to the other drug traffickers.
Chaibat claims that his wife was arrested by the Malaysian Police and only she knows the codes for their Swiss Bank Accounts.During the meeting, Chaibat's gang attack from outside while Ka-Kui and Yang protect him inside. In a huge gun battle, Chaibat's gang kill the rival traffickers and their guards, and smash up the compound. The Thai opium supplier (Lo Lieh) survives but will now sell only to Chaibat at Chaibat's price.The action then shifts to Kuala Lumpur, Malaysia, where Chaibat's wife is being held in prison, and is facing the death penalty. However, Chaibat needs to keep her alive because she knows the secret codes to his Swiss bank account, and she will not reveal them to anyone but her husband.
More difficulties arise when Ka-Kui happens to run into his girlfriend May (Maggie Cheung) at a Malaysian resort hotel. She confronts Ka-Kui, and the situation turns into a misunderstanding, with Panther believing that Ka-Kui was trying to proposition a prostitute.
Later, Ka-Kui is able to corner May and explain the situation, and she finally calms down. At one point, May even manages to keep Ka-Kui from inadvertently blowing his own cover. But then, in an elevator, May tells a co-worker about Ka-Kui, and one of Panther's men overhears her. May is taken hostage, and Ka-Kui and Yang their cover now blown are forced to help Chaibat free his wife Chen Wen-Shi (Josephine Koo).Chaibat's scheme is successful, and May is released, as per their agreement. However, the exchange turns sour when Chaibat pushes May from his helicopter. Furious, Ka-Kui and Yang refuse to let Chaibat and his men escape.
An elaborate stunt-filled action sequence begins that covers the roads, rooftops, and skies of Kuala Lumpur, finally reaching its climax aboard a speeding train, where Chaibat is killed after his helicopter collides into a tunnel and lands on him. Yang and Ka-Kui finally succeed in apprehending Chaibat's wife.
Since her husband is dead, the wife decides to tell Yang and Ka-Kui the password to Chaibat's bank account and the two partners get into an argument over whether Hong Kong or China will take possession of it.
Storyline
A Hong Kong police officer, Ka Kui is sent undercover to mainland China to break up a drug smuggling ring. After breaking the brother of the drug lord out of prison, he and another agent (a beautiful communist policewoman) are taken to Hong Kong to work for the syndicate. The wife of the crime boss has been arrested in Malaysia for drug trafficking and is soon to be executed. However, she is the only person who knows the account number of a secret Swiss bank account containing millions in drug money. While the two officers are in Malaysia preparing for the jail break, Ka Kui accidentally runs into his girlfriend May, who has traveled there from Hong Kong. Soon his cover is blown, the criminals kidnap his girlfriend and he is forced to help them pull off the jail break. — YO