The lives of the residents of a small French town are changed when thousands of the recently dead inexplicably come back to life and try to integrate themselves into society that has changed for them.

Isabelle, a 17-year-old student, loses her virginity during a quick holiday romance. When she returns home, she begins a secret life as a prostitute for a year.

As the dreams of Didier Mathure, a brilliant space engineer, literally go up in smoke when his rocket explodes on take-off, he is transferred to head GEPAN, a unit specializing in UFOs. He is tasked with coming up with scientific explanations for the UFO sightings that are currently dominating the headlines. This is a nightmare job for a die-hard rationalist like him, and he is determined to find a way out as soon as he can.