The opening shows the back story of the two main characters. Luke Wright (Jason Statham) fails to throw a fixed cage fight and in retaliation the Russian mafia kill his pregnant wife and threaten to kill anybody he talks or tries to befriend. Mei (Catherine Chan) is a gifted 12-year old Chinese girl who can memorize any number on sight and do mental math and has been kidnapped by the Chinese mafia to analyze and track their illegal activities in New York without them having to use a computer.
The head of the Chinese mafia shows her a sheet of numbers and has her memorize it. On the way to a 2nd location to memorize another set of numbers the Russians attack and kidnap Mei. A group of corrupt police pit both sides against each other and all three groups are chasing Mei as she escapes from the Russian mafia to a subway where she's spotted by Luke who's just about to commit suicide by throwing himself in front of train. Luke beats up and/or shoots various corrupt officials and mafia goons, rescuing Mei and taking her to a hotel where she tells him the code which he recognizes as a safe combination. Mei is recaptured by the Chinese mafia. It's revealed that Luke used to be a cop and was a former military agent who turned on the force after discovering their corruption. He calls on the former members of his squad to break into a Chinese casino to steal $30 million in cash from the safe.
He then contacts the corrupt mayor's office and discovers that the $30 million was going to be exchanged for a disc containing proof of embezzlement from post 9/11 security operations by high ranking officials. He has his ex military partner retrieve Mei from the Chinese mafia in exchange for offering him the $30 million. His partner tries to double cross him and kill Mei but Luke challenges him to a fight. Before they can fight Mei picks up the gun the partner dropped and shoots him in the leg. Luke finishes off his partner and returns the $30 million to the Chinese mafia, taking Mei with him to Seattle to enroll her in school. They put copies of the disc in various locations as a safe guard against the police coming after them and threaten the Chinese mafia with Mei exposing all their financial transactions if they come after the,.