1978. Didier Mathure, a brilliant space engineer, sees his dream go up in smoke when his rocket explodes on takeoff. When he thought he had hit rock bottom, he was transferred to the head of a specialized UFO investigation office managed by a team that actually gave the impression of living on another planet. Its mission: to find scientific explanations for the appearances of flying saucers which hit the headlines. A real hell for this inveterate Cartesian who has only one idea in mind: to get out of there as quickly as possible. But an extraordinary event will upset his certainties, and open the doors to a world where nothing is impossible.