South of France, summer 2030. Doctor Bernard Rieux finds the corpse of a rat on his landing. He is contacted by Sylvain Rambert, a journalist who came from the capital to investigate strange disappearances which have all been dismissed. Alerted by a town hall employee, Rieux suggests to Rambert to take an interest in the maneuvers of the mayor, ready to do anything to save his summer season, while a mysterious illness begins to spread in town...