The Long, Long HolidaySeptember 1939. Ernest and Colette, 10 and 6 years old, left Paris for a weekend to accompany their parents to Papilou and Mamili, their maternal grandparents in Grangeville, in Normandy. Times are trouble: Hitler has invaded Poland and Austria. The children's father, Robert, is convinced that war will be avoided. Papilou is more pessimistic, he was in the war of 14. The children's mother, Lucie, is ill and her state of weakness worries her relatives. Far from the worries of adults, children enjoy the countryside. Colette becomes infatuated with a suckling pig found on the road to the Morteau farm. Marcelin and Gaston Morteau, the two brothers who live there, take a dim view of the presence of "parigots" in their territory. They go after Ernest. War is declared. Robert has to go to the front, and Lucie is expected at the sanatorium for treatment. Ernest and Colette are going to stay with Papilou and Mamili, until “it calms down”. To take revenge for a humiliation by the Morteaus and please Colette, Ernest steals the piglet from the farm and hides it in his cabin. The Morteaus do not support the affront. A fight breaks out and it is the girl in the woods who comes to save Ernest from his bad posture. Papilou and Mamili, touched by the fate of their grandchildren who will have to stay longer than expected, bought Gadoue. For Ernest, it is the tragedy: not only does he not return to Paris, but he will have to share the school benches with the Morteaus.