1981. Hubert Bonisseur de la Bath, aka OSS 117, is back. For this new mission – more delicate, more dangerous and more torrid than ever – he is forced to team up with a young new colleague, the promising OSS 1001.

Antoine is moving with his mother and little brother in a modern tower with green walls and a sustainable, self-sufficient architecture. In great psychological distress, he feels like a stranger to this new environment.

In 1942, in an occupied Paris, the apolitical grocer Edmond Batignole lives with his wife and daughter in a small apartment in the building of his grocery. When his future son-in-law and collaborator of the German Pierre-Jean Lamour calls the Nazis to arrest the Jewish Bernstein family, they move to the confiscated apartment. Some days later, the young Simon Bernstein escapes from the Germans and comes to his former home. When Batignole finds him, he feels sorry for the boy and lodges him, hiding Simon from Pierre-Jean and also from his wife. Later, two cousins of Simon meet him in the cellar of the grocery. When Pierre-Jean finds the children, Batignole decides to travel with the children to Switzerland.

1969: the Americans walk on the Moon. Mehdi, 10, arrives at Lycée Lyautey, far from his Atlas village. He thinks he's a member of the Apollo crew discovering an unknown planet: who are these French people who live in luxury, love inedible things, talk without modesty and show such interest in him?