Could some part of the mystery be explained away by the doctor's increasing absorption in his studies, which led him to regard the charge of a ward, and a wayward one at that, as unduly onerous and disturbing? Might it not fairly be supposed that ignorant superstition and the ravings of unrequited passion accounted for the rest? At the nature of Dr. Kassimere's studies he could not even guess. The greater number of the works in the library related to mysticism in one form or another, although there was a sprinkling of exact science to leaven the whole. "He can rely upon my word," Waynwright had said. Regarding what, or regarding whom, had he given his word? The cry of a night-hawk came, as if in answer; the hoot of an owl, as if in mockery. Out beyond the terrace a dull red light showed from Dr. Kassimere's laboratory. V Enlightenment came about in this fashion--seeking to quench a feverish thirst, Dillon discovered that no glass had been left in his room. He determined to fetch one from the buffet cupboard downstairs. Softly, in slippered feet, he descended the stairs and was crossing the hallway when he kicked something--a small book, he thought--that lay there upon the floor. Groping, he found it, slipped it into the pocket of his dressing-gown, and entered the dining-room. He found a tumbler without difficulty, in the dark, noted the presence of a heavy, oppressive odour, and returned upstairs. Now he made another discovery. He had forgotten the nightly draught of medicine prescribed by Dr. Kassimere; a new unopened phial stood upon the dressing-table. He mixed himself a mild whisky and soda from the decanter and siphon which his host's hospitality caused nightly to be placed in his room, and then, seized by a sudden thought, took out the little book which he had found in the hall. It was a faded manuscript, in monkish Latin; a copy of an unpublished work of Paracelsus. Many passages had been rendered into English, and the translations, in Dr. Kassimere's minute, cramped writing, were interposed between the bound pages. In these again were interpolated marginal notes, some in the shape of unintelligible symbols, others in that of chemical formulæ. Several passages were marked in red ink. And, having perused the first of these which he chanced upon, a clammy moisture broke out upon his skin, accompanied by so marked a nervous trembling that he was forced to seat himself upon the bed. The secret of this man's ghastly life-work was in his hands; he knew, now, what bargain Dr. Kassimere had proposed to the Frenchman and to the other; he knew why he had adopted the lovely daughter of Louis Devant--and he knew why he, Jack Dillon, had been invited to Hollow Grange. That such a ghoul in human shape could live and have his being amid ordinary mankind was a stupendous improbability which, ten minutes earlier, he would have laughed to scorn. "My God!" he whispered. "My God!"