A disillusioned police detective, used as a scapegoat by his corrupted superior, fights back by becoming a competent criminal.

Marie Lemaire is poisoned during a dinner that brings together an association of merchants. She is the heiress of her recently deceased husband, François, who was the owner of the largest glass factory in the city. All the guests are potential suspects and the investigators must sort out the real from the fake, detect motives and verify alibis. Olivia Rousseau, one of the guests, ex-mistress of François Lemaire who left her to marry Marie, is dead at her home. In a letter, she declared that she had poisoned Marie and killed herself in the same way.

With the help of journalist Diane Castelain, Parisian police inspectors Leo Gorce and Gu Arenas are trying to solve the murder of a member of the French Parliament, but some dangerous powerful people try to make sure that doesn't happen.

It's peak season at Morzine-Avoriaz ski resort. French high mountain state police officer Constance Vivier and Swiss cop Andreas Meyer investigate the suspect death of a teenager, found freezing on a slope after an alcohol coma.