He acted upon it. Focussing the dead face he exposed the plate, and, the picture taken, stole away from the house with the negative in his possession. He subsequently developed the picture and enlarged it, and there, under the lens of a powerful microscope, was the portrait of the murderer upon the pupils of the dead man's eyes. It had been his last living vision, which had fixed itself upon the retina. I have the picture by me now, and since that day have been much interested in the photographic art, in which I have made some curious experiments. Later researches have proved that we can photograph what is invisible to the eye, what is even concealed in a box. The photographs of shadows and the spirits of the dead can be taken. The image of Samuel Boyd being in my mind, found its reflection in a window in a moment of light. Why should we not be able to photograph a vision created by the imagination?" "Or," said Dr. Vinsen, with a touch of sarcasm, "the thoughts of men." "Or," said Dr. Pye, with an assenting nod, "the thoughts of men. It will be done; and when it is accomplished it will open the road to greater discoveries." "Ah," said Dr. Vinsen, shrugging his shoulders, "great discoveries--_your_ great discoveries, ending in visions." "To you, visions; to me, reality. The age of miracles is not yet past. It is my intention to get out of this country, and return to Italy, where there is light, where the sun shines. This atmosphere, these leaden skies, these black nights, are fatal. I must release myself. My purpose is fixed." "And mine." Both spoke in a tone of decision, and both had a motive-spring which had yet to be revealed. "Let us come back to earth," said Dr. Vinsen, "and above all, let us be practical. There are accounts between us which must be settled--pray do not forget that." "I will not." "You were at the inquest to-day," said Dr. Vinsen, rather uneasily, for there was a menace in Dr. Pye's tone. "The papers report you fully. Your warning to the jury not to be led away by a resemblance that might be accidental was a masterstroke. It produced a good effect, but will it assist Mr. Reginald Boyd? We shall see--we shall see. Justice is slow. Were you to formulate a code you would make it swifter, surer--eh, my friend?" "I would make it swift as sudden death to all who stood in my path," said Dr. Pye, and now there was a cold glitter in his eyes as he looked at his visitor.