Richard Malinowski (
Jean Dujardin), Captain of the Homicide squad, promises to take his 10-year-old daughter Emilie for a bike ride. Before they set out, he receives a call from an informant who’s just been arrested and needs Richard to vouch for him at police headquarters. While Richard is gone, Emilie goes off alone on her bike.
That same afternoon, joggers find her body – she's been raped and beaten to death. The police quickly arrest Daniel Eckmann (Laurent Lucas) near the place of the crime. The overpowering evidence quickly finds the suspect convicted. From prison, Eckmann writes to Richard saying that he's innocent. He urges the bereaved cop to conduct his own investigation centering on a recently arrested serial killer named Salinas (Jean-Francois Garreaud), whose m.o. seems to fit the crime...