Albert, the gamekeeper, lives with his wife and their two children in the house in the woods. In 1917, they welcomed three boys whose fathers had gone to the front. When they are not in school, children play at war and hide in the forest.
The gendarmes investigate a thief who gleefully picks from the common reserve of the village. Hervé sympathizes with the elegant Count, and has lunch in his castle.
A pleasant Sunday countryside party is organized by the inhabitants of the house of the woods. This lull is disturbed by serious news: Marcel, one of Hervé's two companions, is called to go to the front.
A garrison stops near the village and the children see real soldiers for the first time. One of them offers his baptism to Hervé, who is overjoyed. But death is never far from the village and one of the planes crashes by accident.
Hervé's father is visiting his son for the first time in a year. The reunion is timid and infinitely happy. But the boy soon learns the news of the death of his companion Marcel.
It is finally the armistice. The children participate in a party before leaving the house of the woods forever. Hervé finds his father in Paris and discovers his new "mother" and his half-sister Brigitte, with whom he will now live.
While Parisian life seems very boring to Hervé, "papa Jacques" the gamekeeper, pays him a surprise visit. His wife is very sick and he is desperate. Hervé then decides to run away to go to her and see the house of the woods one last time.