Plot Summary:Mylène teams up with Fred to solve the murder of Morgane, a young chef whose body is found in the "forges de Buffon", her lungs blown up by nitrogen. Alain Malaval, her partner and a former cop is in state of shock and brings Fred's suspicion on him. Simultaneously, another body is found. It's Captain Deville's, who's been missing for several years and happened to be Mylène's father. Are the two murders connected?