The widowed children's book author Charles Thénier (Michel Duchaussoy) lives a secluded life with his 9-year-old son Martin. He is suddenly run over by a car and dies - the driver flees unrecognized. The police investigators soon file the case, but Charles believes he recognized the television actress Hélène Lanson (Caroline Cellier) in the accident car. He makes her acquaintance under a false name. Hélène falls in love with him and a series of sinister entanglements takes its course - towards a dramatic end.