Crooks, cops and an heir-apparent get a dose of Old West justice when Chon Wang (Jackie Chan) and his woman-hungry partner, Roy O'Bannon (Owen Wilson), reunite to hunt down a killer.
After riding together in Shanghai Noon, the men parted company with O'Bannon heading east to invest the pair's accumulated money. But when his "investments" in fast women and hard drinks fail to turn a profit, O'Bannon resorts to waiting tables, working as a male gigolo and embellishing Old West adventure stories to sell to the public.
Wang settles down in Carson City, Nevada to work as a local sheriff, but his life changes after receiving a letter from his sister. A Chinese rebel group known as the Boxers has stormed the Forbidden City, stolen the Emperor's ancient royal seal and murdered the lawman's estranged father who guarded it.
Packing his saddlebags, Wang treks to the big city and hits up O'Bannon for some much needed cash to travel to England where the insurgents have fled. Unable to tender any financial assistance, the published author agrees instead to come along and lend a hand searching for the criminals.
Arriving in the seedy streets of London, they discover Wang's sister Chon Lin (Fann Wong) has made her way there, too, promising revenge on the thieves. Shadowing the men who took her father's life, she uncovers a conspiracy that leads straight to the country's royal family. But her attempt to take out the assassin lands her in the care of Scotland Yard and Detective Artie Doyle (Tom Fisher).
Taking on the Brits in typical Jackie Chan style, the actor (now approaching 50) manages to make an impressive showing of the martial arts skills that form the base of his film appeal. Coming up against worthy opponents like the evil Wu Yip (Dennie Yen) provides ample film footage for Chan followers. The agile actor also uses an umbrella to stave off crooks and trades sword thrusts with the queen's distant relative (Aiden Gillen) amid the wooden trusses of Big Ben.
But kicks, punches and wild flips still add up to liberal amounts of unwarranted violence despite the often-comical feel to the exchanges. Pair that with O'Bannon's sexual antics in a brothel, bawdy banter and a kinky sex book found in an aristocrat's library, and this film comes up with enough content to misfire in the family entertainment arena. Maybe moviemakers should just let Jackie do what Jackie does best and leave the sexual high jinks for another film.