The series "Une affaire française" is a crime drama based on real criminal cases that shook France in different years. The central plotline focuses on the case of Gregory Villemin. This four-year-old boy was kidnapped from his home in 1984. After extensive searches, the police found the child on October 16th... unfortunately, already dead. The identity of the perpetrator remains unknown to this day. However, the investigation has several, to varying degrees, insane theories that will be presented on screen.