On the Atlantic coast, bales of pure cocaine were found at low tide several days ago. That morning, the body of Lucas Lagne, captain and son of a family that owned a shipyard in the region, was found. Sarah, a gendarmerie captain, is in charge of the investigation and will have to team up with Ben, from the narcotics squad, who has just been called in as backup by the prosecutor. The surprise of meeting face to face is great. 19 years ago, they lived in the same city, where Sarah fled when she was pregnant..