On the coast of Normandy in May 1944, the peaceable Jérôme lives in his crumbling château with his widowed mother and his beautiful young wife Marie, daughter of Dimanche, a local farmer.

Snooping around the estate is a stranger named Julien who fascinates Marie, seeing in him a means of escaping the twin boredoms of rusticity and matrimony.

In fact he is a Free French officer liaising with Dimanche, who heads the local Resistance, to survey German fortifications before the imminent Allied landings.

When Dimanche explains that American paratroops are being dropped that night and must be guided to the back of the blockhouse, Jérôme says that the Germans have covered the landing zone with stakes.

Jérôme, still dressed for dinner, walks into the beam and engages the Germans in incoherent conversation until he is close enough to throw a grenade that knocks out the light.