Just at that moment, as though summoned by these words from the bowels of the earth, a man slowly stepped into the circle of blue light that fell from the window-a man thin and pale, a man with long hair, in a black doublet, who approached the foot of the bed where Sainte-Croix lay.  Brave as he was, this apparition so fully answered to his prayers (and at the period the power of incantation and magic was still believed in) that he felt no doubt that the arch-enemy of the human race, who is continually at hand, had heard him and had now come in answer to his prayers.  He sat up on the bed, feeling mechanically at the place where the handle of his sword would have been but two hours since, feeling his hair stand on end, and a cold sweat began to stream down his face as the strange fantastic being step by step approached him.  At length the apparition paused, the prisoner and he stood face to face for a moment, their eyes riveted; then the mysterious stranger spoke in gloomy tones.

“Young man,” said he, “you have prayed to the devil for vengeance on the men who have taken you, for help against the God who has abandoned you.  I have the means, and I am here to proffer it.  Have you the courage to accept?”

“First of all,” asked Sainte-Croix; “who are you?”

“Why seek you to know who I am,” replied the unknown, “at the very moment when I come at your call, and bring what you desire?”

“All the same,” said Sainte-Croix, still attributing what he heard to a supernatural being, “when one makes a compact of this kind, one prefers to know with whom one is treating.”

“Well, since you must know,” said the stranger, “I am the Italian Exili.”

Sainte-Croix shuddered anew, passing from a supernatural vision to a horrible reality.  The name he had just heard had a terrible notoriety at the time, not only in France but in Italy as well.  Exili had been driven out of Rome, charged with many poisonings, which, however, could not be satisfactorily brought home to him.  He had gone to Paris, and there, as in his native country, he had drawn the eyes of the authorities upon himself; but neither in Paris nor in Rome was he, the pupil of Rene and of Trophana, convicted of guilt.  All the same, though proof was wanting, his enormities were so well accredited that there was no scruple as to having him arrested.  A warrant was out against him:  Exili was taken up, and was lodged in the Bastille.  He had been there about six months when Sainte-Croix was brought to the same place.  The prisoners were numerous just then, so the governor had his new guest put up in the same room as the old one, mating Exili and Sainte-Croix, not knowing that they were a pair of demons.  Our readers now understand the rest.  Sainte-Croix was put into an unlighted room by the gaoler, and in the dark had failed to see his companion:  he had abandoned himself to his rage, his imprecations had revealed his state of mind to Exili, who at once seized the occasion for gaining a devoted and powerful disciple, who once out of prison might open the doors for him, perhaps, or at least avenge his fate should he be incarcerated for life.