Béatrice Radian

The owner of a casino and the owner of a luxury hotel in Deauville are eternal rivals.

An unemployed investor creates a fictious business partner to attempt to improve business. Eventually, his creation gets out of control as his business becomes successful and his wife announces that she is in love with the partner and his son wishes the partner was his father -- although no one has ever seen him. To regain control, the man decides to "kill" his imaginary partner and is arrested for the murder.