Le pas de trois (1964)

A duke lives a secluded life, in an isolated castle-like mansion, overlooking the Atlantic ocean and with a private beach; he is a man with a secret, and passes his days collecting miniature plumb soldiers. One day, a young man arrives on the scene, intent on blackmailing the duke - and for that he will use his manly charm with the duke's waitress, daughter, and even the Duchess...