Plot: Alex and Alicia team up to investigate the murder of a Cistercian monk. It leads them to the discovery of a formula derived from a plant, which has been kept secret by the order.
Plot: A young, freshly graduated commissioner is assigned a case of an old man who was found hanged. Accompanied by a reporter, she begins her investigation to bring the murderer to justice.
Plot: Clara and her assistant Guillaume Barot set out to investigate a dead body found in an old apartment. Things change when they discover that the person was murdered 70 years ago.
Plot: When a shepherd is found murdered, the villagers suspect a former teacher to be the killer. Two investigating officers try to solve the case, and, in the process, they unravel several other issues.