At the end of 1972, con artist and thief Simon receives a remission to celebrate the New Year outside La Santé Prison. While heading to his apartment in Paris to meet his mistress Françoise, Simon notices that a car is chasing his cab. In the apartment, Simon leans that Françoise has a lover and he leaves the place without being noticed. Simon recalls the Christmas of 1966, when he travels out-season to Cannes with his partner and friend Charlot to heist the jewellers Van Cleef and Arpels. While plotting a scheme to rob the jewellers, Simon meets the intellectual antique dealer Françoise whose shop is the next-door neighbor of the target and he falls in love with her. But his scheme does not work as planned and Simon is arrested.