James "Jimmy" Tong (Jackie Chan) is a taxi driver notorious for his speed and ability to get his customers anywhere in the least amount of time. His reputation lands him a job as the personal chauffeur of the mysterious but wealthy Clark Devlin (Jason Isaacs). Jimmy does not really know what his new boss' job is, but Devlin's friendly nature, imperturbable demeanor, and willingness to offer Jimmy advice wins Jimmy over and the two become friends. What Jimmy does not realize is that Devlin is a secret spy and undercover government agent, and when an attempt to kill Devlin with a car bombing sends him into a coma, Jimmy ends up with Devlin's recent case notes and a special watch that controls Devlin's rather unusual tuxedo.