Lucas, Lucien, Luigi, and Ludwig live in the orphanage of the Abbey of Valencourt in Picardy. In the summer of 1914, their teacher, like many others, is drafted, but at that time, no one can imagine that he will be gone for a long time. For the children, the war is a distant terror, yet it draws closer, and one day they hear the sound of artillery fire. They decide to flee, but when the orphanage is evacuated, they are left behind. Alone, they suddenly find themselves behind German lines and must fight for their survival...