NOTE: This spoiler was sent in by EstherC who says..."The show lacks substantive plot but is filled with humor."
The movie opens with Carter (Chris Rock) on traffic duty in the middle of a busy cross-junction. He is listening a catchy tune on his iPOd while directing traffic with his hand actions/dance moves. He gets caught up in the music and gives the wrong signals, which causes an accident and car-pileup. Instead of admitting his mistake, he tries to pin the blame on 2 chicks in a Mercedes sports car, but with the real intention of picking them up for a date.
Carter calls Lee (Jackie Chan) who is a bodyguard for Ambassador Han. They are on their way to an international conference. Lee tries to limit the conversation with Carter; seems they are not on good terms. At the conference, it is revealed that Ambassador Han has been asked to lead the task force to crackdown on the international gangsters and Triads who are responsible for the world's major crimes. A major success to the crackdown is the revealing of ShiShang. Ambassador Han is introduced by the international head of the organization, Reynard. In the middle of his speech, Ambassador Han is shot by an assassin sniper, and Lee gives chase. He goes after the shooter.
Meanwhile, Carter hears about the shooting over the police radio and hijacks the girls' sports car and gives chase. He spots Lee chasing the assassin and goes to assist. Lee manages to corner the assassin, only to find out it is someone he knows from his past, a 'brother' named Kenji. They both draw guns, but Kenji knows Lee will not shoot him (Lee having always been Kenji's protector in the orphanage in ChangZhou). Just then, Carter arrives in the sports car but tries to ram Kenji down. He misses and nearly whacks Lee. Kenji escapes.
At the hospital, the duo are informed that Ambassador Han survived. His daughter, Soo Yung arrives and makes the 2 promise to find the assassin. Soo Yung tells Lee that she has kept an important letter her father passed to her for safekeeping in a locker safe in Chinatown. Carter and Lee head for Chinatown. It is revealed that the 2 'broke up' because Carter shot Lee's girlfriend Isabella in the neck, resulting in her being 'injured' and taken back by the secret service (funny dialogue).
In Chinatown, they go to the martial arts school where the locker is. Carter does it hardball and ends up getting thrashed by a really tall big guy. [The whole scene is a slapstick] The master "You" is blind and tells them that the locker was already busted into and Soo Yung is in danger. They rush back to the hospital in time to thwart and attack by the triads.
They capture one of the traid attackers who speak French (another hilarious scene). With the help of a nun translator, they find out that they have to go to Paris to locate a Genevieve. At the airport, their cover is busted by the French police who are suspicious of their intentions in the country. (They get beaten and violated by the police captain). They also run into some argument with the french taxi driver.
They go to the street where the gentlemen's club and Genevieve is located. In the club, Lee gets into a colorful fight with a female Asian assassin whilst Carter tries to pick up a very pretty lady (important). They escape in the taxi only to be car-chased by more triad members. Carter tells the french taxi driver to imagine he is an American spy and to drive and dodge the followers.
When they finally lose them, they realize that Genevieve is the headliner for a showgirl show. Carter sneaks into the back while Lee goes to front and stakes out triad members waiting to kill Genevieve when she comes on stage. Genevieve turns out to the be the girl in the casino Carter was trying to hit on. They save her in time. In the hotel room, they ask Genevieve who ShiShang is. She says it is her. She removes her wig and there is a list of 13 names tattooed on her skull. The list is important as it is the secret identity of the 13 snakeheads/gang leaders of the world. The revealing of the list means the gangs will lose all power and secrecy. Genevieve, (herself an ex-gangster) was going to reveal the list to Ambassador Han but Kenji found out and now there is a price on her head. They promise to protect her.
They go to Reynard for protection, only to find out he is a traitor and he works for the triad, under the very guise of being chief on an international organization Kenji calls for Lee and issues an exchange - Genevieve for Soo Yung.
The showdown takes place at the Eiffel Tower. Soo Yung is held hostage dangling from the tower. Lee and Kenji battle it out over the structure with Samurai swords. Later, they are both left hanging from scaffolding when it starts to give way. Lee tries to save Kenji again but Kenji decides to let go and falls to his death. Carter meanwhile takes on the hoodlums and manages to also subdue the Asian lady assassin who tries to kill Soo Yung. They escape from the tower using a gigantic french flag as a parachute down to the fountain at the plaza. Reynard tries to kill them but is shot by the taxi driver (still humourously acting out as an American spy).
They dance away and the movie ends.