France in the year 1940. Paris is occupied by German troops, thousands flee to the countryside. Among them Odile with her two children Philippe and Cathy. Soon their trek of refugees is attacked by a German fighter plane. The people look for cover in the ditch, some escape through a corn field. Amidst this chaos the three meet Ivan, together they find refuge in an abandoned farm house.
Odile is relieved to have found somebody who knows how to get the things to survive.
She feels attracted to him and later passes him off as her oldest son. But there is something bewildering about him: he does not know how to read and write, he is always restless, and hardly gives any information about himself.