He was a bachelor. I often wondered why, for he seemed of a type that would be immensely attractive to women. He did not avoid them; the pose of a woman-hater would have been abhorrent to him. Yet no woman to my knowledge had ever interested him, even mildly. Except his sister. They were orphans and she was his constant companion. They were both in fact, rather chary of friends; absorbed in their work, in which she took an active part. Their home and laboratory was an unpretentious frame cottage in a Westchester village of suburban New York. They lived quietly, modestly, with only one automobile, and no 'plane. Will opened the door for me himself, smiling as he extended his big, hearty hand. "Well! You came, Rob? You're very forgiving--that's the mark of a true friend." He led me into the old-fashioned sitting room. "I'm not going to apologize--" "Don't," I said. "I knew of course you had some reason--" We were seated. He said with a nod, "Yes. A reason--you'll hear it now--tonight--" His voice trailed away. It made my heart beat faster. He had changed. I saw him suddenly older. "Where's Bee?" I asked out of the silence. He jerked himself back from his reverie. "Upstairs. She'll be down in a moment. She's been ill, Rob." "But you said not seriously." "No. She's better now. It's been largely mental--she's been frightened, Rob. A terrible strain--that's why I thought it better for us to isolate ourselves for a while--" "Oh, then that's why--" "That's why I wrote you so peremptorily not to come to see us any more. I was upset myself, I needn't have been so crude--" "Please don't apologize, Will. I--I didn't understand, but--" "I'm not. I'm just telling you. But now Bee thought we should have you with us. Our best friend, you understand? And it will make things easier for her--naturally she's frightened--" My hand went to his arm. What I had meant to say I do not know, for Bee at that moment entered the room. A girl of twenty-four. Tall, slim and graceful. She was dressed now in a clinging negligee which seemed to accentuate the slim grace of her. But the marks of illness were plain upon her face; a pallor; her eyes, though they smiled at me with the smile of greeting upon her lips, had the light of fear in them; her hand as I took it was chill, and its fingers felt thin and wan. "Bee!" "It's good to see you, Rob. Will has been apologizing for us, I suppose--" These friends of mine calling me to them in their hour of need. I had been annoyed, hurt; I had not realized how deep was my affection for them ... for Bee.... Vaguely I wondered now if their trouble--this fear that lay so obviously upon them both--concerned the coming of the ghosts.... Bee sat close beside me, as though by my nearness she felt a measure of protection. * * * * * Will faced us. For a moment he was silent. Then he began, "I have a good deal to say, Rob--I want to be brief--"