Antoine Verlay is an intuitive police officer who appreciates efficiency and complicated investigations. Appreciated by his hierarchy, he was entrusted by Commander Pardo with a unique dossier. Indeed, at the Château d'Amboise, a painting representing Anne of Brittany was stolen. However, this theft caused a victim: a corpse was found in the gardens. Ignoring everything about Renaissance painting, Verlay was forced to collaborate with Florence Chassagne. This specialist in the history of art is brilliant but totally devoid of tact. Together, they try to determine if the a priori unspecified work does not hide an invaluable painting ...

Despite the tensions that arise between Florence and Antoine, Commander Pardo remains convinced of the effectiveness of their duo. He wants them to shed light on the affair of the stolen painting in Amboise. Little by little, Florence comes to accumulate the elements of proof allowing to arrive at a stupefying hypothesis: the portrait of Anne of Brittany would it in fact conceal an unknown work of Leonardo da Vinci? At his side, Antoine essentially wants to solve the murder that was committed in the gardens of the Château d'Amboise, and is not very sensitive to the artistic excitement of his partner ...

The Central Office for Combating Trafficking in Cultural Goods is investigating the murder of a student during a party organized in the basements of a prestigious Parisian art school. Florence Chassagne is contacted by Commander Prado to help Antoine Verlay. Their collaboration hardly excites the young policeman. However, Florence sheds precious light during the first investigations. When it appears that the deceased had stolen two works by Watteau, his theory upsets Antoine's certainties. At the same time, Pierre Chassagne's difficulties increased. He then turns to his daughter, but she intends to protect herself now that she is beginning to overcome her recurring psychological difficulties ...

The investigation continues but the difference in approach between Florence and Antoine complicates the investigation. In addition, the presence of an ex-boyfriend of Florence only complicates the ongoing investigations. Did the victim lead a double existence? What criminal esthete could hold it against him to the point of cutting his throat at the foot of one of the major works of the Louvre? Engaged in his expeditious methods inherited from the PJ from which he was dismissed, Antoine stamps his feet. Little by little, in the corridors of the prestigious establishment, they discover a major clue ...

Delphine, an art historian, is uneasy during a visit to the Louvre Museum, during which specialists assess the degradation of the famous painting 'The Raft of the Medusa', by Théodore Géricault. She died before the arrival of help, her eyes fixed on the monumental canvas. While his divorce has just been pronounced, Antoine takes note of the file. Florence Chassagne, for her part, finishes a psychotherapy session during which she claims to have finally freed herself from all her phobias. Antoine takes him to the Louvre, to collect the first clues and testimonies. Florence knew the victim, who succumbed to poisoning ...