1978. Didier Mathure, a brilliant space engineer, sees his dream go up in smoke when his rocket explodes during take-off. Just when he thought he had hit rock bottom, he is transferred to the head of a UFO investigation office managed by a team that gives the impression of living on another planet. His mission: to find scientific explanations for the sightings of flying saucers that have become the talk of the town. A real hell for this inveterate Cartesian who has only one idea in mind: to get out of there as soon as possible. But an extraordinary event will upset his certainties, and open the doors to a world where nothing is impossible.