Eddie Yang (Jackie Chan) is a Hong Kong police officer cooperating with Interpol in the capture of a crime lord named AJ "Snakehead" Staul. Snakehead (Julian Sands). Snakehead buys an ancient book from a Chinese bookstore keeper. It is the story of a boy being chosen every thousand years, to bind the two halves of a legendary medallion. The touch of the medallion would endow the receiver with superhuman strength and immortality.In Hong Kong, a team of Interpol agents, led by Agent Arthur Watson (Lee Evans), are preparing to capture Snakehead and his men, who are planning to kidnap the boy. Watson decides to apprehend Snakehead inside the temple, over Eddie's objections. Eddie wants Hong Kong police to lead, but Watson is adamant that this is an Interpol mission. Eddie is left in the van as Watson and his team go in. Watson is a bumbling fool and not very adept at covert anti-terrorist operations.Eddie enters the temple when he sees a bright light emanating from it, which was a result of the boy bringing the pieces of the medallion together. Eddie and the Interpol agents fight Snakehead's men inside a temple where the boy, named Jai (Alex Bao), is kept. Jai is saved as Watson and Eddie reach the inner chamber of the temple together before Snakehead can capture Jai. Snakehead and his men escape. Two weeks later, Jai is captured and is held aboard a cargo boat in Hong Kong. Eddie and a team of Hong Kong Police agents again engage and defeat several of Snakehead's men. Eddie realizes that Jai is on the ship as well. A few of Snakehead's men escape with Jai to Dublin, Ireland.In Ireland, Eddie is assigned by Hong Kong police to find Jai and bring him back to safety. But Watson is not happy to be working under Eddie's command. Eddie is also reunited with his girlfriend, a British agent named Nicole James (Claire Forlani). The British team is led by Commander Hammerstock-Smythe (John Rhys-Davies). Jai was last seen on the ship with Snakehead's #2 man Lester Wong (Anthony Wong). Nicole tells Eddie that they need Watson for the investigation. So, they visit his home to convince him. Watson's family doesn't know he is Interpol and believe he is a librarian. The trio have a good time and Watson agrees if he is allowed to lead the mission.By chance Eddie later encounters one of Snakehead's top men while entering a cab. After catching him, he confesses Jai is being held in the Dublin harbor. Eddie, Watson, and Nicole move to rescue Jai, defeating several Snakehead agents in the process. Eddie and Jai end up trapped inside a container, which is knocked into the water by Lester Wong before they can be released by Nicole and WatsonEddie keeps Jai alive by an inflatable tent, but himself drowns. After being rescued, Jai uses his medallion on Eddie's body. In the morgue, Watson is grieving over Eddie's body when he suddenly appears beside him. Eddie realizes Jai used the medallion to resurrect him, and his former body vanishes into nothingness. Jai splits the medallion into its two halves, giving one of them to Eddie. Snakehead's men appear in the hospital to recapture Jai and during the fight, Eddie discovers the medallion has also granted him superhuman strength and immortality. Eddie asks Watson to keep his resurrection a secret from Nicole and the others. Eddie and Watson consult an expert on ancient mythology and find that the medallion can resurrect life and give strength. But you need both halves of the medallion and the boy to bring them together. The expert says that the medallion can also take life away.Jai is with Nicole for protection. Eddie reveals to Nicole that he is alive, and they get reconcile. Jai is captured again by Snakehead via a helicopter attack. Jai is forced to use the medallion on Snakehead, but with only one half of it, he gains superhuman strength but is still mortal. Snakehead and his men attack Watson's family and steal the other half of the medallion. Watson's Chinese wife reveals herself to be a police operative like him, much to Watson's surprise as he kept his job secret from his family. Together they fight off the attack from Snakehead's men.Snakehead attacks Eddie himself and defeats him in one-to-one battle and takes the 2nd half of the medallion from him. Eddie, Watson and Nicole learn Snakehead's hideout is in a castle called "Raven's Keep" and go to finish him once and for all. The operation runs smoothly at first, but Snakehead kills Nicole and has become immortal.He and Eddie engage in a vicious fight, until Eddie used the medallion to take away the life it gave; Snakehead is destroyed. Jai allows Eddie to use the medallion to resurrect Nicole, who also gains super-strength and immortality. The two run off into the distance, and Jai enters a portal to another world.