That conceit is key to the open eroticism of On a Magical Night, which contrasts with Hollywood’s current asexual immorality. This heterosexual story shows Honoré acceding to moral tradition — to ethical argument, not fashionable politics about gender. Chiara Mastroianni, combing aspects of her parents Marcello Mastroianni and Catherine Deneuve, makes an uncanny embodiment of that complex effort.