After a car accident in which his mother dies, Antoine Chapelote decides to change his life and become a con-artist. He meets a young girl Caroline who helps him with his scam.
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...
Victor Vautier is incorrigible: he's in constant motion, working several cons at once, using different names and changing disguises. He's charming and outrageous, incapable of uttering a sentence that isn't embellished or an outright lie. His life goal is to make enough money to build a sea wall to protect Mont-Saint-Michel. Charlotte, a parole officer, shows up: she's young and seems taken in by Victor. He discovers she lives above the Senlus Museum, where her parents are the curators. With two pals he decides to steal a priceless El Greco triptych and then ransom it back to the cultural ministry. What will Charlotte do when she realizes he's used her to make a fortune?
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.
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.