At Pignerol, Fouquet was treated with great rigour. Some few months after his arrival there, a peril of another kind came very near to him. The lightning of a heavy thunderstorm struck the powder-magazine of the fortress, and it exploded, burying many in its ruins. Fouquet, who was standing at the moment in the recess of a window, remained unhurt. Mystery hangs over the last days of his life; for while it is said that he died in his captivity at Pignerol, his friend Gourville states that he was set at liberty before his death. Voltaire also declares that Fouquet’s daughter-in-law, the Comtesse de Vaux, confirmed the fact of this to him. Another surmise, and one that found wide acceptance, is that although he was liberated for a while, he was rearrested, and that it was he who was the mysterious individual known as the Man in the Iron Mask. Human Nature loves a mystery, and would resent being deprived of this most memorable enigma in modern history, by any reasonable and certain solution of it, could it be beyond all doubt and question established. Again and again it has been explained and explained away, but it is, as Galileo declared of the earth and the sun: _e pur se muove_. The Man in the Iron Mask stands the Man in the Iron Mask—which was, in fact, not of iron, at all, but of stoutly-lined velvet, as the _loups_ and masks of the time nearly always were made. Probably this mask was secured by extra strong springs and fastenings, as mostly was the case for prisoners of distinction, when they were being conveyed from one place of captivity to another. Such kind of explanation was afforded to Ninon by the governor of the Bastille when she discussed the point with him. There was, he said, no mystery at all in it. Yet the possibility remains that it did not suit the governor of the grim old prison-house absolutely to lift the veil covering its secrets, even to Ninon.