“Well, then, I must explain two things to you. In the first place, you can imagine a current passing along a wire from one side of a room to the other. When a circuit is made a bell rings. Now, the wire which carries that current may be insulated thoroughly, yet it diffuses around it a certain quantity of static electricity, or magnetism, which constitutes an aura.” “Ah, an old friend, met in many a clairvoyant novel and mesmeric séance!” “Yet the aura has dynamic existence apart from fiction. Place a smaller wire, equipped with an electro-magnet yielding to one tenth of the force carried by wire No. 1, in the same field, but wholly separate, and you will find that by completing the first circuit the resultant magnetism affects the second wire, and _its_ bell rings also, only with considerable diminished strength. Well, sweep away your visible appliances, regard me as wire No. 1, and mankind in general as wire No. 2, and you have a fairly accurate notion of the manner in which I can ascertain, and even control, other people’s words and movements at any given moment.” “How about me?” I demanded. “I was exceedingly anxious to communicate with you the other evening, but nothing happened, to _my_ knowledge.” “Had I known your wish, and you had given voice to it, it would have been different. But that brings me to my second illustration. The force, whatever it is, which travels forth comes back again with absolutely unimpaired vigor, though possibly in some other form. You can prove that little recognized fact by experiment with any sparking machine. Now, there is only one human being alive, so far as I know, who can actually supply the full magnetic complement of my electric field. In different words, there is but one other creature on earth tuned to my pitch. Owing to certain impending circumstances I fear a collapse for her, or through her, which will, beyond question, be accompanied by a more complete catastrophe for me.” Karl was speaking so seriously, his words were so evidently the outcome of deep reflection, that I found myself as profoundly imbued with the vital importance of the matter as he was himself. “Are you alluding to the Honorable Nora Cazenove or to Miss Margaret Hutchinson?” I asked. The bewildering pendulum-swing from talk of sudden and unprovided death back to light-hearted and careless gaiety was not the least puzzling feature of Karl’s present attitude; he straightened himself in his chair and laughed gleefully. “I wonder if you can discover the answer unaided!” he cried. “I’ll tell you what. There’s a reception at Sandilands’ house to-night. Just slip on your regulation clothes, and I’ll take you there. After you have seen Nora, you shall give me your opinion!” CHAPTER XVII I MEET NORA CAZENOVE “Having carried what may be termed your technical exposition so far, why do you stop short at the really important issue?” I asked.