There it was, and behind it a house empty as my heart has been since that day. A man's dress covering a woman's form--and over the motionless, perfect features, that same smile which I had seen in the room beyond and again in the quick glare of the rifles. I had harbored no evil thought concerning her, but when I beheld that smile now sealed and fixed upon her lips, I found the soul I had never known I possessed until that day. A MYSTERIOUS CASE. It was a mystery to me, but not to the other doctors. They took, as was natural, the worst possible view of the matter, and accepted the only solution which the facts seem to warrant. But they are men, and I am a woman; besides, I knew the nurse well, and I could not believe her capable of wilful deceit, much less of the heinous crime which deceit in this case involved. So to me the affair was a mystery. The facts were these: My patient, a young typewriter, seemingly without friends or enemies, lay in a small room of a boarding-house, afflicted with a painful but not dangerous malady. Though she was comparatively helpless, her vital organs were strong, and we never had a moment's uneasiness concerning her, till one morning when we found her in an almost dying condition from having taken, as we quickly discovered, a dose of poison, instead of the soothing mixture which had been left for her with the nurse. Poison! and no one, not even herself or the nurse, could explain how the same got into the room, much less into her medicine. And when I came to study the situation, I found myself as much at loss as they; indeed, more so; for I knew I had made no mistake in preparing the mixture, and that, even if I had, this especial poison could not have found its way into it, owing to the fact that there neither was nor ever had been a drop of it in my possession. The mixture, then, was pure when it left my hand, and, according to the nurse, whom, as I have said, I implicitly believe, it went into the glass pure. And yet when, two hours later, without her having left the room or anybody coming into it, she found occasion to administer the draught, poison was in the cup, and the patient was only saved from death by the most immediate and energetic measures, not only on her part, but on that of Dr. Holmes, whom in her haste and perturbation she had called in from the adjacent house. The patient, young, innocent, unfortunate, but of a strangely courageous disposition, betrayed nothing but the utmost surprise at the peril she had so narrowly escaped. When Dr. Holmes intimated that perhaps she had been tired of suffering, and had herself found means of putting the deadly drug into her medicine, she opened her great gray eyes, with such a look of child-like surprise and reproach, that he blushed, and murmured some sort of apology. "Poison myself?" she cried, "when you promise me that I shall get well? You do not know what a horror I have of dying in debt, or you would never say that."