In the beginning of world war one Lucien Bersot, a farrier and young father has joined the army.During the distribution of clothes Lucien receives white trousers instead of the regular red trousers.Some days later during a troop inspection an officer insists that Lucien must wear the regular red trousers; a sergeant presents him red trousers with blood stains coming from a corpse of a soldier.Lucien does not accept these red trousers and is then arrested until his judgment in the martial court.