In 1788, France supports the revolt of the American colonies against Great Britain. While all await the birth of an heir to the throne, the Queen of France faces mounting criticism. A jewel stolen during the Opera ball becomes the stakes for several plots. Reconciled with Sartine, Nicolas le Floch's mission is to spy on the highly suspicious Duc de Chartres, the king's cousin. He joins him to fight in the naval Battle of Ouessant, first episode in the war with England.
Upon his return, several provocative crimes set him on the trail of a mysterious and ruthless assassin. What ambiguous games are being played by Inspector Renard and his wife? Why does the name of the king's brother, Count de Provence, keep coming up everywhere? Le Floch must face unspeakable horror and endanger his life in order to seek out the criminals.
He will run into the unfathomable Restif de la Bretonne, Mesmer the faith healer and his sidekick, the painter Saint-Aubain and the monk of the royal Chapelle. Le Floch will succeed in taking apart this intricate web of crime in an ultimate and quite unexpected development.
The eighth investigation by the famous commissioner of Ch telet whose adventures have now been adapted by France 2. French Ambassador to Guin e-Bissau, specialist of the 18th century, Jean-Fran ois Parot takes us into the heart of intrigue, both in the king's court and on the streets of Paris under the reign of Louis XV and Louis XVI.