 Jo Guardini, now the peaceful owner of a charming inn by the banks of the River Marne, once was a dreaded gangster. The respectful citizen does not want to have anything to do with the underworld any more. Unfortunately, two of his former accomplices kidnap a little girl and decide to hide her in his hotel. What will Jo do : side with the law in the person of inspector Loriot or have a relapse in crime?