In a Jura village split by the Loue river, the border between occupied France and the free zone runs through the town, turning daily life into a tense boundary of risk and loyalty. The Nazis intensify their crackdown on the resistance, announcing that anyone attempting to cross the line will be shot. Pierre, comte de Damville, an aristocratic French officer, is released by Nazi soldiers to oversee his chateau, now converted into a German command center, forcing him to take residence in the nearby hunting lodge. He accepts that France has effectively lost the war and maintains a surprisingly cordial rapport with the German governor, a fellow aristocrat. Yet his British-born wife Mary de Damville throws her weight behind the resistance, risking her life to aid those who oppose the occupying force. Early on, she is shown arranging the successful escape of downed Allied airmen, guiding them across occupied France toward Spain and Gibraltar, a daring act that reveals both her courage and the peril surrounding them.
Meanwhile, a crooked smuggler operates in the town, charging a Jewish family large sums to cross the river but betrays them to the Nazis and steals their possessions. In retribution, the Resistance eliminates the trafficker, underscoring the brutal costs paid by those who profit from oppression. The tale widens to focus on two British spies hidden in the forest, gathering military information and broadcasting it back to London. Their presence is soon discovered by the Germans, one is wounded and captured, and the balance of the town’s clandestine networks teeters on a knife’s edge. If the captured spy were to break, the entire local network could be exposed and crushed.
At the hospital, Doctor Jacques Lafaye, a doctor and member of the Resistance, tries to stall the Germans, resisting the pressure to begin interrogations. But two energetic Gestapo agents push to proceed, threatening harsher measures. Resistance operatives, dressed in German uniforms, mount a ruse—staging a raid on the hospital and extracting the wounded spy before the real Germans can arrive. The Gestapo, furious and relentless, hunt for the hidden traveler, and threaten to arrest and torture the doctor’s wife, prompting the doctor to choose self-sacrifice rather than betray those who rely on him. An informer reveals the spy’s location, but the wounded man is moved elsewhere by the Resistance before the Gestapo can strike.
The Germans eventually arrest Mary, though they have no concrete evidence against her; as a British aristocrat, she would be interned rather than tortured, a distinction that speaks to the era’s capricious moral codes. In a village-wide effort, the Resistance enlists the local priest in a bold plan to smuggle the wounded spy to the opposite bank of the river inside the coffin of a recently deceased 97-year-old woman. The coffin procession nearly reaches the bridge, but the two Gestapo agents become suspicious and order a stop to inspect the coffin. It is at this moment that [Pierre] draws a pistol and shoots the two agents dead, only to fall to German gunfire himself. The scene ends with the villagers gathered around his body, defiantly singing the French anthem, La Marseillaise, as the camera lingers on the cold, emblematic Nazi flag fluttering over occupied France.
