After an unfortunate wedding, Agnes Le Roux returns from Africa to her mother Renee, the owner of the Palais de la Méditerranée Casino, and falls in love with her mother’s charge d'affaires Maurice Agnelet, a handsome lawyer 10 years older than her. As one of the casino’s shareholders, Agnes to sell her share to become independent, but her mother is against it. In the midst of the conflict between the mafia and the casino owners, Maurice goes over to the enemy and offers Agnes three mission francs if she votes against her mother…