After half-an-hour I left, and more puzzled than ever, returned to the house in Richmond Road. Sometimes I felt entirely convinced that my love was authoress of the foul deed; yet at others there seemed something wanting in the confirmation of my suspicions. Regarding the latter I could not overlook the fact that Short had told a story which was false on the face of it, while the utter absence of any motive on my love's part in murdering the old gentleman seemed to point in an entirely opposite direction. Dr. Diplock, the coroner, had fixed the inquest for eleven o'clock on the morrow; therefore I assisted Dr. Farmer, of Kew, the police surgeon, to make the post-mortem. We made the examination in the afternoon, before the light faded, and if the circumstances of the crime were mysterious, the means by which the unfortunate man was murdered were, we found, doubly so. Outwardly, the wound was an ordinary one, one inch in breadth, inflicted by a blow delivered from left to right. The weapon had entered between the fourth and fifth ribs, and the heart had been completely transfixed by some sharp cutting instrument. The injuries we discovered within, however, increased the mystery ten-fold, for we found two extraordinary lateral incisions, which almost completely divided the heart from side to side, the only remaining attachment of the upper portion to the lower being a small portion of the anterior wall of the heart behind the sternum. Such a wound was absolutely beyond explanation. The instrument with which the crime had been committed by striking between the ribs had penetrated to the heart with an unerring precision, making a terrible wound eight times the size within, as compared with the exterior puncture. And yet the weapon had been withdrawn, and was missing! For fully an hour we measured and discussed the strange discovery, hoping all the time that Sir Bernard would arrive. The knife which the man Short confessed he had taken down in self-defence we compared with the exterior wound and found, as we anticipated, that just such a wound could be caused by it. But the fact that the exterior cut was cleanly done, while the internal injuries were jagged and the tissues torn in a most terrible manner, caused a doubt to arise whether the Indian knife, which was double-edged, had actually been used. To be absolutely clear upon this point it would be necessary to examine it microscopically, for the corpuscles of human blood are easily distinguished beneath the lens. We were about to conclude our examination in despair, utterly unable to account for the extraordinary wound, when the door opened and Sir Bernard entered. He looked upon the body of his old friend, not a pleasing spectacle indeed, and then grasped my hand without a word. "I read the evening paper on my way up," he said at last in a voice trembling with emotion. "The affair seems very mysterious. Poor Courtenay! Poor fellow!"