"The cause?" he echoed, in his deep guttural German. "It is for us to discover that. I have never met a more interesting case than this." "Yes, it's interesting enough," I admitted; "but recollect the lady. We must not neglect her." "We are not neglecting her," he responded reprovingly. "Now that we know something of the symptoms, we may be able to save her. Before, we were working entirely in the dark." "But you are still ill," I said. "No, no," he laughed; "it is nothing." And he passed across the threshold and stood just within the room again. Apparently he thought that the seat of the mystery lay in the doorway. Then he rejoined us, but felt no further symptoms. There was evidently some uncanny but unseen influence contained within that apartment, but what it was we could not discover. All that was plain to us was the fact that any person emerging from it must be struck down as by an ice-cold hand. Together we returned to the boudoir, and, to our satisfaction, saw an unmistakable sign that life was not entirely extinct. My love had moved! "Good!" exclaimed the old German. "I go again to get something else." And, without further word, he crammed his shabby soft felt hat upon his head and hurried out. "The mystery of that room is most extraordinary," I remarked to her ladyship when we were alone. "Has the influence ever been felt there before?" "Not to my knowledge," she responded. "Never before to-night." "Never before the entrance of that strange woman?" I suggested. "Exactly! It is an absolute mystery." "And you have no knowledge of whom that person was?" "None whatever." "Not even a surmise?" I inquired rather dubiously. My thoughts reverted to what I had overheard regarding the unwelcome presence in London of that woman known as "La Gioia." "No, not even a surmise," she answered. Should I tell her of my own suspicions? No. To keep my knowledge to myself and seek to discover the key to the problem was my best course. "And your cousin was with her for twenty minutes, you say?" "Yes, about that time," she replied. "I did not hurry to finish my dinner as I believed Beryl was talking with the dressmaker regarding some alterations to an evening bodice which she had mentioned to me. They did not interest me, therefore I sat awaiting her return." "And by that time this woman, whoever she was, had already slipped out of the house." "She must have done so. No one heard her leave." "Let us hope that Hoefer will solve the enigma. If any one is able, he is." "But first urge him to bring poor Beryl back to consciousness," she said, turning to gaze upon the still inanimate form of the woman I adored. At that moment the German returned, puffing and grunting, for he had hurried, and the perspiration was rolling off his brow.