June 1944, a French town towards the end of the occupation. Following several attacks perpetrated by the resistance, the inhabitants who listen to English radio are rounded up by the Germans in a prison and considered as hostages. In one of the cells are found men from all walks of life: an aristocrat, the Viscount of Saint-Leu, Doctor Noblet, a resistance fighter, Béquille the wanderer with a wooden leg, and a strange character nicknamed "Black Market". The latter arouses mistrust among the prisoners, because it could well have been introduced by the enemy.

Amiens, sous l'Occupation. Un certain nombre de Français sont incarcérés et doivent servir d'otages si le convoi d'essence arrêté en gare doit subir un attentat. Celui-ci a lieu, les otages seront fusillés au matin. La nuit passe avec des réactions diverses de la part des prisonniers. Prévenue par radio, la Royal Air Force bombarde la prison au moment de l'exécution. Les condamnés qui réchappent de l'opération gagnent le maquis.