Whilst working for the CIA, Jackie (Jackie Chan) is assigned to follow leads of a nuclear smuggling case. He follows a woman named Natasha to Ukraine. When he realizes that she had been hiding vital information, Jackie calls for backup and she is later arrested. However, Natasha’s partner is an unknown man, who turns out to be Jackson Tsui (Jackson Lou), a Chinese-American nuclear scientist with CIA links, suspected of stealing a nuclear warhead. Jackie follows Tsui to a restricted area, and after a trap set by Tsui, the CIA agents together with Ukrainian authorities engage in battle. Jackie finds a briefcase which contained evidence from Tsui, but as he is chased by unknown forces, Ka-kui loses the briefcase as he falls into frozen waters.
When he recovers in Russia, he meets Colonel Gregor Yegorov (Yuriy Petrov) who explains the situation. Jackie goes with the FSB and is taken to Moscow where he discovers he has been assigned to work with Gregor to solve a similar case involving nuclear weapons being smuggled out of Ukraine. His task is to track Tsui, who disappeared after their last encounter. He is taken by a Russian submarine to Brisbane, Australia, where Tsui’s younger sister Annie (Wu Chen-chun) works at an aquarium doing shark shows. Uncle 7 (Terry Woo), the Tsuis’ father and the local Triad boss, is seriously ill and Jackie suspects the criminal will show up soon. Unknown to Jackie, Tsui is hiding at the hospital and has given a nuclear warhead (disguised as a small oxygen tank) to Annie, who hides it at the aquarium.
While following Annie, Jackie gets held up by Tsui, who claims to have a deal with Gregor. Jackie, after realizing he has been used by Gregor, decides to return home, but two men are sent to kill him, and he is framed for the murder of Uncle 7. He attempts to clear his name by going to see Annie at the memorial hall, but he is (unsurprisingly) unwelcome, having to fight the family’s bodyguards until Tsui arrives to clear Jackie’s name. Tsui explains that Gregor caught him on a CIA assignment three years before, and forced him to turn into a triple agent: a CIA agent ostensibly turned by the FSB, but in reality serving Gregor’s private criminal schemes.
Annie, Jackie, and Tsui decide to work together to find Gregor and bring him in. Uncle 7’s elaborate Chinatown funeral becomes the scene for a complex shootout between the various parties. Annie and Jackie attempt to retrieve the stolen warhead from the shark pool (so that they can return it to the police), but Gregor and his men follow them, leading to a climactic confrontation underwater. During the fight, Gregor shoots the aquarium and shatters the glass, which releases the killer shark. During the confusion, Gregor escapes with the warhead and kidnaps Annie to a getaway boat. Jackie saves the tourists from the shark and then pursues Gregor. While Gregor escapes in the getaway boat, Jackie finds and drives a Mitsubishi FTO display car onto the boat. The car pins Gregor, allowing Jackie to successfully retrieve the warhead and save Annie.
Gregor and Tsui are apprehended by the Australian police and turned over to Russian authorities. The case is solved, and Jackie is thanked for his work by the FSB and returns to his work in Hong Kong.