Perhaps it was childish on my part, but I accepted this curt dismissal very ill-humouredly. That Harley, for some reason of his own, wished to be alone, was evident enough, but I resented being excluded from his confidence, even temporarily. It would seem that he had formed a theory in the prosecution of which my coöperation was not needed. And what with profitless conjectures concerning its nature, and memories of Val Beverley’s pathetic parting glance as we had bade one another good-night, sleep seemed to be out of the question, and I stood for a long time staring out of the open window.
 
The weather remained almost tropically hot, and the moon floated in a cloudless sky. I looked down upon the closely matted leaves of the box hedge, which rose to within a few feet of my window, and to the left I could obtain a view of the close-hemmed courtyard before the doors of Cray’s Folly. On the right the yews began, obstructing my view of the Tudor garden, but the night air was fragrant, and the outlook one of peace.
 
After a time, then, as no sound came from the adjoining room, I turned in, and despite all things was soon fast asleep.
 
Almost immediately, it seemed, I was awakened. In point of fact, nearly four hours had elapsed. A hand grasped my shoulder, and I sprang up in bed with a stifled cry, but:
 
“It’s all right, Knox,” came Harley’s voice. “Don’t make a noise.”
 
“Harley!” I said. “Harley! what has happened?”
 
“Nothing, nothing. I am sorry to have to disturb your beauty sleep, but in the absence of Innes I am compelled to use you as a dictaphone, Knox. I like to record impressions while they are fresh, hence my having awakened you.”
 
“But what has happened?” I asked again, for my brain was not yet fully alert.
 
“No, don’t light up!” said Harley, grasping my wrist as I reached out toward the table-lamp.
 
His figure showed as a black silhouette against the dim square of the window.
 
“Why not?”
 
“Well, it’s nearly two o’clock. The light might be observed.”
 
“Two o’clock?” I exclaimed.
 
“Yes. I think we might smoke, though. Have you any cigarettes? I have left my pipe behind.”
 
I managed to find my case, and in the dim light of the match which I presently struck I saw that Paul Harley’s face was very fixed and grim. He seated himself on the edge of my bed, and:
 
“I have been guilty of a breach of hospitality, Knox,” he began. “Not only have I secretly had my own car sent down here, but I have had something else sent, as well. I brought it in under my coat this evening.”
 
“To what do you refer, Harley?”
 
“You remember the silken rope-ladder with bamboo rungs which I brought from Hongkong on one occasion?”
 
“Yes—”
 
“Well, I have it in my bag now.”
 
“But, my dear fellow, what possible use can it be to you at Cray’s Folly?”
 
“It has been of great use,” he returned, shortly.
 
“It enabled me to descend from my window a couple of hours ago and to return again quite recently without disturbing the household. Don’t reproach me, Knox. I know it is a breach of confidence, but so is the behaviour of Colonel Menendez.”
 
“You refer to his reticence on certain points?”
 
“I do. I have a reputation to lose, Knox, and if an ingenious piece of Chinese workmanship can save it, it shall be saved.”
 
“But, my dear Harley, why should you want to leave the house secretly at night?”
 
Paul Harley’s cigarette glowed in the dark, then:
 
“My original object,” he replied, “was to endeavour to learn if any one were really watching the place. For instance, I wanted to see if all lights were out at the Guest House.”
 
“And were they?” I asked, eagerly.
 
“They were. Secondly,” he continued, “I wanted to convince myself that there were no nocturnal prowlers from within or without.”
 
“What do you mean by within or without?”
 
“Listen, Knox.” He bent toward me in the dark, grasping my shoulder firmly. “One window in Cray’s Folly was lighted up.”
 
“At what hour?”
 
“The light is there yet.”
 
That he was about to make some strange revelation I divined. I detected the fact, too, that he believed this revelation would be unpleasant to me; and in this I found an explanation of his earlier behaviour. He had seemed distraught and ill at ease when he had joined Madame de Stämer, Miss Beverley, and myself in the drawing room. I could only suppose that this and the abrupt parting with me outside my door had been due to his holding a theory which he had proposed to put to the test before confiding it to me. I remember that I spoke very slowly as I asked him the question:
 
“Whose is the lighted window, Harley?”
 
“Has Colonel Menendez taken you into a little snuggery or smoke-room which faces his bedroom in the southeast corner of the house?”
 
“No, but Miss Beverley has mentioned the room.”
 
“Ah. Well, there is a light in that room, Knox.”
 
“Possibly the Colonel has not retired?”
 
“According to Madame de Stämer he went to bed several hours ago, you may remember.”
 
“True,” I murmured, fumbling for the significance of his words.
 
“The next point is this,” he resumed. “You saw Madame retire to her own room, which, as you know, is on the ground floor, and I have satisfied myself that the door communicating with the servants’ wing is locked.”
 
“I see. But to what is all this leading, Harley?”
 
“To a very curious fact, and the fact is this: The Colonel is not alone.”
 
I sat bolt upright.
 
“What?” I cried.
 
“Not so loud,” warned Harley.
 
“But, Harley—”
 
“My dear fellow, we must face facts. I repeat, the Colonel is not alone.”
 
“Why do you say so?”
 
“Twice I have seen a shadow on the blind of the smoke-room.”
 
“His own shadow, probably.”
 
Again Paul Harley’s cigarette glowed in the darkness.
 
“I am prepared to swear,” he replied, “that it was the shadow of a woman.”
 
“Harley——”
 
“Don’t get excited, Knox. I am dealing with the strangest case of my career, and I am jumping to no conclusions. But just let us look at the circumstances judicially. The whole of the domestic staff we may dismiss, with the one exception of Mrs. Fisher, who, so far as I can make out, occupies the position of a sort of working housekeeper, and whose rooms are in the corner of the west wing immediately facing the kitchen garden. Possibly you have not met Mrs. Fisher, Knox, but I have made it my business to interview the whole of the staff and I may say that Mrs. Fisher is a short, stout old lady, a native of Kent, I believe, whose outline in no way corresponds to that which I saw upon the blind. Therefore, unless the door which communicates with the servants’ quarters was unlocked again to-night—to what are we reduced in seeking to explain the presence of a woman in Colonel Menendez’s room? Madame de Stämer, unassisted, could not possibly have mounted the stairs.”
 
“Stop, Harley!” I said, sternly. “Stop.”
 
He ceased speaking, and I watched the steady glow of his cigarette in the darkness. It lighted up his bronzed face and showed me the steely gleam of his eyes.
 
“You are counting too much on the locking of the door by Pedro,” I continued, speaking very deliberately. “He is a man I would trust no farther than I could see him, and if there is anything dark underlying thi............