Francois Marboni is a butcher who is being blackmailed for having an affair with the prostitute Rachel. He decides to hire a hit man when the blackmailer demands that he start cutting his profit margin to the bone. Francois soon becomes a target of the hit-man he hired.
Grégoire Lecomte, the unlucky actor anxious to find a "real job", goes to take a screen test for a role of a killer, but gets to mafiosi by mistake. He takes their don for a producer, and they mistake him for a hitman with whom they had an appointment. Deluded Lecomte signs contract with them. He is supposed to kill gun dealer Otto Krampe at his birthday party in Saint-Tropez by piercing him with a cap of the umbrella with a built-in syringe with potassium cyanide. Lecomte is not aware that it has to be a real murder.
Dressed as a clown, the clever rascal Grimm holds up the most secure bank of Montreal and takes 30 hostages. While confusing and ridiculing the police with his strange behavior, he calmly manages to rid the bank of a fortune. But then an unsatisfied companion arouses trouble...
A hitman, his boss, an art dealer and a money-laundering scheme that accidentally turns the assassin into an overnight avant-garde sensation, one that forces her to play the art world against the underworld.
Alphonse Tram is unwittingly involved in several murders despite having no memory of committing the crimes. His confusion lead him to confess to his neighbour, Inspector Morvandieu. Alphonse and Morvandieu become the axis around which murders occur.