 While traveling to Lisbon for a lecture, the famous middle-aged publisher and lecturer Pierre Lachenay (Jean Desailly) has one night stand with the young Panair do Brasil stewardess Nicole (as Françoise Dorleac). They start a love affair traveling to Reims together, and Pierre hides from his unbalanced wife Franca Lachenay (Nelly Benedetti), trying to spare his daughter Sabine Lachenay (Sabine Haudepin) from a separation. However, Pierre gets involved with Nicole, misunderstanding her feelings and expectations, and decides to live with her, leaving Franca, leading the couple to a tragic end.