Like every year, the billionaire Claude Tranchant (Benoît Poelvoorde) and his wife Eliane (Virginie Hocq) have invited the who's who of show business to their sumptuous villa in Saint-Tropez, France. Nothing seems to be able to spoil the festivities, until the disturbing sabotage of the couple's convertible. Convinced this was an attempted murder, Tranchant tries to arrange for the services of the best cop in Paris. But in the heart of summer, only the arrogant and incompetent commissioner Boulin (Christian Clavier) is available. To catch the suspect and solve the mystery, he will have no choice but to impersonate a newly hired butler and turn everyone's vacation into a hilarious game of Clue.