In the countryside near Normandy's beaches lives Marie, unhappy. It's 1945, she's married to JTr(me, a somewhat fussy milquetoast, diffident to the war around him and unwilling to move his wife to Paris, where she longs to live, shop, and party. A German outfit is bivouacked at JTr(me and Marie's crumbling chGteau because its commanding officer is pursuing Marie. She's also eyed by a French spy working with the Allies as they plan D-Day. He woos her (posing to the Germans as her brother) and, in his passion, forgets his mission. Heroics come from an unexpected direction, and Marie makes her choice.

In Normandy at the time of the German occupation, Marie becomes bored with her lackluster married life with Jérôme, a phlegmatic country squire 20 years her senior, and dreams of living in Paris. Consequently, she is delighted by the sudden unexpected arrival of a handsome parachutist, Julien, who has come to make preparations for the destruction of a German shore gun before D-Day. He makes contact with Marie's father, Dimanche, the local resistance leader, and then reluctantly returns to England. Meanwhile, Klopstock, a German officer, billets himself and his company at the dilapidated family chateau in order to pursue Marie. Julien is returned dead drunk, to Normandy, and to explain his presence to the Germans, Marie and Jérôme pretend that he is her brother. Klopstock, hopeful of winning Marie's gratitude, showers Julien with kindness. Marie and Julien run off, and Jérôme decides that it is time to assert himself if he is to keep his wife. He assumes Julien's hazardous mission of guiding the American parachutists who are to destroy the gun and becomes a hero. As Allied invasion troops arrive, Julien departs for adventures elsewhere while Marie gazes at her husband with a new look of admiration.