"But I'm certain he's not in his room, now," said Pat. "In fact, I've proved he's out, and wandering about."
"Proved?" I asked, amazed, as Jane moved to my side.
"Yes, proved, dear Livingston," Jane whispered. "She tied a silk thread across the hall, between her door and mine, after we came home from the banquet."
"Oh, I see!" I remarked, lightly.
"Nothing to be amused about," said Pat, with a wan, twisted smile. "I did it to prove to Aunt Jane that Mr. Zzyx was snooping about. She stayed in here with me, and we waited to see if anything happened."
"And nothing happened for half an hour," Jane supplemented, taking a good sniff of her sal volatile.
"When, suddenly, we heard something moving outside, in the hall," Pat resumed. "After a few minutes, and we didn't hear anything more, I switched off the lights in here, opened the door a few inches, and looked out. The hall was dark. I could hear the muffled sound of your voice, and Bob's, in his room. That gave me courage, so I stole outside to investigate. I found the thread had been broken."
"That's queer," I observed. "Still, it might have been broken by the butler. Schweizer suffers terribly from insomnia, and has a habit of roaming about the place at night, at unearthly hours. I really don't understand."
"But I do," Jane said, in a low, guttural voice; "and it's your business, Livingston, to rid this place of that terrible creature at once. If you don't, and I should see him roving about, in the dark, I know I'll die of heart failure, instantly." She placed strong emphasis on the last word, and took another strong whiff of her smelling salts.
At that Pat turned to me, the tears welling in her eyes. "Oh, Uncle Livingston!" she said, earnestly and pleadingly; "isn't there any chance at all of ending this terrible mystery business about Mr. Zzyx and Mars? Uncle Henry must be losing his mind, or he wouldn't be associated with anything so unearthly and—spooky!"