Luisa lives with Mathieu, the man she loves, and Arthur, Mathieu's son by his first wife, who died in an accident. But Arthur, whom Luisa has been raising like her own, suddenly disappears from school and no one claims a kidnapping.

In may 1940, the German troops enter France. Frightened by the progress of the enemy, the people of a small village of Pas-de-Calais decide on the recommendations of the prefecture, to give up everything to go on the road, fleeing to the coast.