Gary, an unskilled young man, lands a job as a decontamination sub-contractor at a nuclear power plant in the lower valley of the Rhone. Inducted into the workforce by supervisor Gilles and veteran Toni, Gary discovers that radiation contamination is not just a risk factor but an everyday hazard. At the same time, he begins an illicit affair with Karole, Toni's fiancée. It turns out that Toni is sterile, and Karole becomes pregnant by Gary.