It is the year 1660, and D'Artagnan, after thirty-five years of loyal service, has become disgusted with serving King Louis XIV while the real power resides with the Cardinal Mazarin, and has tendered his resignation. He embarks on his own project, that of restoring Charles II to the throne of England, and, with the help of Athos, succeeds, earning himself quite a fortune in the process. D'Artagnan returns to Paris to live the life of a rich citizen, and Athos, after negotiating the marriage of Philip, the king's brother, to Princess Henrietta of England, likewise retires to his own estate, La Fere. Meanwhile, Mazarin has finally died, and left Louis to assume the reigns of power, with the assistance of M. Colbert, formerly Mazarin's trusted clerk. Colbert has an intense hatred for M. Fouquet, the king's superintendent of finances, and has resolved to use any means necessary to bring about his fall. With the new rank of intendant bestowed on him by Louis, Colbert succeeds in having two of Fouquet's loyal friends tried and executed. He then brings to the king's attention that Fouquet is fortifying the island of Belle-Ile-en-Mer, and could possibly be planning to use it as a base for some military operation against the king. Louis calls D'Artagnan out of retirement and sends him to investigate the island, promising him a tremendous salary and his long-promised promotion to captain of the musketeers upon his return. At Belle-Isle, D'Artagnan discovers that the engineer of the fortifications is, in fact, Porthos, now the Baron du Vallon, and that's not all. The blueprints for the island, although in Porthos's handwriting, show evidence of another script that has been erased, that of Aramis. D'Artagnan later discovers that Aramis has become the bishop of Vannes, which is, coincidentally, a parish belonging to M. Fouquet. Suspecting that D'Artagnan has arrived on the king's behalf to investigate, Aramis tricks D'Artagnan into wandering around Vannes in search of Porthos, and sends Porthos on an heroic ride back to Paris to warn Fouquet of the danger. Fouquet rushes to the king, and gives him Belle-Isle as a present, thus allaying any suspicion, and at the same time humiliating Colbert, just minutes before the usher announces someone else seeking an audience with the king. [Book Three of the D'Artagnan Romances was serialized as four separate volumes in the magazine Le Siecle from October 1847 to January 1850: The Vicomte de Bragelonne, Ten Years Later, Louise de la Valliere, and The Man in the Iron Mask.]