October 16, 1984. The body of Grégory Villemin, 4 years old, was found drowned in Vologne. While journalists flock from all over France, the gendarmes, led by Captain Sesmat, follow the trail of a mysterious crow who has been harassing the child's family for years...

New elements allow Judge Lambert to order the custody of a potential suspect in Grégory's death, under the eyes of raging journalists. This arrest sows disorder in the Villemin family. For their part, the gendarmes question the suspect's sister-in-law…

While the gendarmes believe they have the culprit for Grégory's death in the person of Bernard Laroche, their witness reconsiders his confession, which seems to bring the investigation to a standstill. But new unexpected witnesses quickly bring to light a new theory...