How the thing came thus to light and through whom, I have no means of ascertaining, and so I must leave it to the reader to decide the question for himself. But, as the “Prudenza trionfante” contains a minute description of Mattioli’s arrest, in the words, “The secretary (Mattioli) was surrounded by ten or twelve horsemen, who seized him, disguised him, _masked_ him, and conducted him to Pinerolo,” we can only conclude either that it must have been written by an eyewitness, or else from the description given by one of the scene in question. Moreover, there were alive, until the Eighteenth Century, many persons of the parts about Pinerolo who continued to bear witness both to Mattioli’s arrest as well as to the manner of it, especially in regard to his masking by Catinat’s men. After all, what explanation more natural than that (for the day was a Sunday) some small boys or other idlers should have followed the march of Catinat and his few soldiers, at a respectful distance, along the three miles of road from Pinerolo to the place of the arrest and, concealing themselves among the dense trees nearby, should have seen everything? Thus, the mystery of Mattioli’s disappearance from the world of the living was in no way a mystery, except in the fond imagination of his gaolers, seeing that the facts of it were public property over a great part of Europe, after the appearance of the publications mentioned in 1682 and 1687. There arises then the question—whence the mystery of the “Man in the Iron Mask”? From the early spring of 1694 until the summer of 1698, when Saint-Mars was promoted to be the governor of the Bastile in Paris, Mattioli remained under his care at the Island of Sainte-Marguerite. At the end of those four years Saint-Mars is told to come to Paris and to bring with him his “ancient prisoner” in such a manner that he shall be seen by no one. And so Saint-Mars set out for his new post in the capital, taking with him his “ancient prisoner,” masked as ever, in a litter, with an escort of horse-soldiers. On their way they passed by Saint-Mars’ estate of Palteau, near Villeneuve in the Department of the Yonne, where Saint-Mars rested for a day or two, never letting his prisoner out of his sight; together they ate their meals, and at night Saint-Mars slept in a bed close to that of the man in the mask. In a letter upon the subject published in the “Année Littéraire” for June 30, 1768, and quoted in his admirable book by Mr. Tighe Hopkins, the grand-nephew of Saint-Mars, M. de Formanoir de Palteau, writes: