Duc d'Orléans starts to make his move against the Four Musketeers with the help of Saint-Germain and Caron under the banner of the Revolutionary Brethren. Meanwhile, Louis and Broglie reveal the existence of a progressive faction supporting the French Revolution behind the scenes to D'Eon and his companions. They also reveal that Lia had been found dead shortly after she had been dispatched to Russia as an agent of Le Secret du Roi. D'Eon and his companions accept the invitation to join Le Secret du Roi, and they pursue Vorontsov, a Russian spy working for Orléans. They are unable to capture Vorontsov, and Caron kills himself after confronting D'Eon and Lia.