People were about me the whole time. Hence I had no opportunity of re-examining the little object I had picked up from the spot where the murderer must have stood.

When morning dawned two detectives from Scotland Yard arrived, made notes of the circumstances, examined the open window in the conservatory, hazarded a few wise remarks, and closely scrutinised the dagger in the hall.

Ethelwynn had taken her sister to a friend in the vicinity, accompanied by the nurse and the cook. The house was now in the possession of the police, and it had already become known in the neighbourhood that old Mr. Courtenay was dead. In all probability early passers-by, men on their way to work, had noticed a constable in uniform enter or leave, and that had excited public curiosity. I hoped that Ambler Jevons would not delay, for I intended that he should be first in the field. If ever he had had a good mystery before him this certainly was one. I knew how keen was his scent for clues, and how carefully and ingeniously he worked when assisting the police to get at the bottom of any such affair.

He came a little after nine in hot haste, having driven from Hammersmith in a hansom. I was upstairs when I heard his deep cheery voice crying to the inspector from Scotland Yard:

“Hulloa, Thorpe. What’s occurred? My friend Doctor Boyd has just wired to me.”

“Murder,” responded the inspector. “You’ll find the doctor somewhere about. He’ll explain it all to you. Queer case—very queer case, sir, it seems.”

“Is that you, Ambler?” I called over the banisters. “Come up here.”

He came up breathlessly, two steps at a time, and gripping my hand, asked:

“Who’s been murdered?”

“Old Mr. Courtenay.”

“The devil!” he ejaculated.

“A most mysterious affair,” I went on. “They called me soon after three, and I came down here, only to find the poor old gentleman stone dead—stabbed to the heart.”

“Let me see him,” my friend said in a sharp business-like tone, which showed that he intended to lose no time in sifting the matter. He had his own peculiar methods of getting at the bottom of a mystery. He worked independently, and although he assisted the police and was therefore always welcomed by them, his efforts were always apart, and generally marked by cunning ingenuity and swift logical reasoning that were alike remarkable and marvellous.

I gave him a brief terse outline of the tragedy, and then, unlocking the door of the room where the dead man still lay in the same position as when discovered, allowed him in.The place was in darkness, so I drew up the Venetian blinds, letting in the grey depressing light of the wintry morning.

He advanced to the bed, stood in the exact spot where I had stood, and where without doubt the murderer had stood, and folding his arms gazed straight and long upon the dead man’s features.

Then he gave vent to a kind of dissatisfied grunt, and turned down the coverlet in order to examine the wound, while I stood by his side in silence.

Suddenly he swung round on his heel, and measured the paces between the bed and the door. Then he went to the window and looked out; afterwards making a tour of the room slowly, his dark eyes searching everywhere. He did not open his lips in the presence of the dead. He only examined everything, swiftly and yet carefully, opening the door slowly and closing it just as slowly, in order to see whether it creaked or not.

It creaked when closed very slowly. The creaking was evidently what the under-housemaid had heard and believed to be the creaking of boots. The murderer, finding that it creaked, had probably closed it by degrees; hence it gave a series of creaks, which to the girl had sounded in the silence of the night like those of new boots.

Ambler Jevons had, almost at the opening of his inquiry, cleared up one point which had puzzled us.

When he had concluded his examination of the room and re-covered the dead face with the sheet, we emerged into the corridor. Then I told him of the servant’s statement.

“Boots!” he echoed in a tone of impatience. “Would a murderer wear creaking boots? It was the door, of course. It opens noiselessly, but when closed quietly it creaks. Curious, however, that he should have risked the creaking and the awakening of the household in order to close it. He had some strong motive in doing so.”

“He evidently had a motive in the crime,” I remarked. “If we could only discover it, we might perhaps fix upon the assassin.”

“Yes,” he exclaimed, thoughtfully. “But to tell the truth, Ralph, old chap, the fact which is puzzling me most of all at this moment is that extraordinary foreboding of evil which you confessed to me the day before yesterday. You had your suspicions aroused, somehow. Cudgel your brains, and think what induced that very curious presage of evil.”

“I’ve tried and tried over again, but I can fix on nothing. Only yesterday afternoon, when Sir Bernard incidentally mentioned old Mr. Courtenay, it suddenly occurred to me that the curious excitement within me had some connection with him. Of course he was a patient, and I may have studied his case and given a lot of thought to it, but that wouldn’t account for such an oppression as that from which I’ve been suffering.”

“You certainly did have the blues badly the night before last,” he said frankly. “And by some unaccountable manner your curious feeling was an intuition of this tragic occurrence. Very odd and mysterious, to say the least.”

“Uncanny, I call it,” I declared.

“Yes, I agree with you,” he answered. “It is an uncanny affair altogether. Tell me about the ladies. Where are they?”

I explained how Mrs. Courtenay had been absent, and how she had been prostrated by the news of his death.

He stroked his moustache slowly, deeply reflecting.

“Then at present she doesn’t know that he’s been murdered? She thinks that he was taken ill, and expired suddenly?”

“Exactly.”

And I went on to describe the wild scene which followed my admission that her husband was dead. I explained it to him in detail, for I saw that his thoughts were following in the same channel as my own. We both pitied the unfortunate woman. My friend knew her well, for he had often accompanied me there and had spent the evening with us. Ethelwynn liked him for his careless Bohemianism, and for the fund of stories always at his command. Sometimes he used to entertain us for hours together, relating details of mysteries upon which he had at one time or another been engaged. Women are always fond of mysteries, and he often held both of them breathless by his vivid narratives.

Thorpe, the detective from Scotland Yard, a big, sturdily-built, middle-aged man, whose hair was tinged with grey, and whose round, rosy face made him appear the picture of good health, joined us a moment later. In a low, mysterious tone he explained to my friend the circumstance of Short having admitted possession of the knife hanging in the hall.

In it Ambler Jevons at once scented a clue.

“I never liked that fellow!” he exclaimed, turning to me. “My impression has always been that he was a sneak, and told old Courtenay everything that went on, either in drawing-room or kitchen.”

Thorpe, continuing, explained how the back door had been found unfastened, and how Short had admitted unfastening it in order to go forth to seek the assassin.

“A ridiculous story—utterly absurd!” declared Jevons. “A man doesn’t rush out to shed blood for blood like that!”

“Of course not,” agreed the detective. “To my mind appearances are entirely against this fellow. Yet, we have one fact to bear in mind, namely, that being sent to town twice he was afforded every opportunity for escape.”

“He was artful,” I remarked. “He knew that his safest plan was to remain and face it. If, as seems very probable, the crime was planned, it was certainly carried out at a most propitious moment.”

“It certainly was,” observed my friend, carefully scrutinising the knife, which Thorpe had brought to him. “This,” he said, “must be examined microscopically. You can do that, Boyd. It will be easy to see if there are any traces of blood upon it. To all appearances it has been recently cleaned and oiled.”“Short admits cleaning it, but he says he did so three days ago,” I exclaimed.

He gave vent to another low grunt, from which I knew that the explanation was unsatisfactory, and replaced the knife in its faded velvet sheath.

Save for the man upon whom suspicion had thus fallen, the servants had all gone to the house where their mistress was lodged, after being cautioned by the police to say nothing of the matter, and to keep their mouths closed to all the reporters who would no doubt very soon be swarming into the district eager for every scrap of information. Their evidence would be required at the inquest, and the police forbade them, until then, to make any comment, or to give any explanation of the mysterious affair. The tongues of domestics wag quickly and wildly in such cases, and have many times been the means of defeating the ends of justice by giving away important clues to the Press.

Ambler Jevons, however, was a practised hand at mysteries. He sat down in the library, and with his crabbed handwriting covered two sheets of paper with notes upon the case. I watched as his pencil went swiftly to work, and when he had finished I saw him underline certain words he had written.

“Thorpe appears to suspect that fellow Short,” he remarked, when I met him again in the library a quarter of an hour later. “I’ve just been chatting with him, and to me his demeanour is not that of a guilty man. He’s actually been upstairs with the coroner’s officer in the dead man’s room. A murderer generally excuses himself from entering the presence of his victim.”

“Well,” I exclaimed, after a pause, “you know the whole circumstances now. Can you see any clue which may throw light on the affair?”

He slowly twisted his moustache again; then twisted his plain gold ring slowly round the little finger on the left hand—a habit of his when perplexed.

“No, Ralph, old chap; can’t say I do,” he answered. “There’s an unfathomable mystery somewhere, but in what direction I’m utterly at a loss to distinguish.”

“But do you think that the assassin is a member of the household? That seems to me our first point to clear up.”

“That’s just where we’re perplexed. Thorpe suspects Short; but the police so often rush to conclusions on a single suspicion. Before condemning him it is necessary to watch him narrowly, and note his demeanour and his movements. If he is guilty he’ll betray himself sooner or later. Thorpe was foolish to take down that knife a second time. The fellow might have seen him and had his suspicions aroused thereby. That’s the worst of police inquiries. They display so little ingenuity. It is all method—method—method. Everything must be done by rule. They appear to overlook the fact that a window in the conservatory was undoubtedly left open,” he added.

“Well?” I asked, noticing that he was gazing at me strangely, full in the face.“Well, has it not occurred to you that that window might have been purposely left open?”

“You mean that the assassin entered and left by that window?”

“I mean to suggest that the murder might have been connived at by one of the household, if the man we suspect were not the actual assassin himself.”

The theory was a curious one, but I saw that there were considerable grounds for it. As in many suburban houses, the conservatory joined the drawing-room, an unlocked glass door being between them. The window that had been left unfastened was situated at the further end, and being low down was in such a position that any intruder might easily have entered and left. Therefore the suggestion appeared a sound one—more especially so because the cook had most solemnly declared that she had fastened it securely before going up to bed.

In that case someone must have crept down and unfastened it after the woman had retired, and done so with the object of assisting the assassin.

But Ambler Jevons was not a man to remain idle for a single moment when once he became interested in a mystery. To his keen perception and calm logical reasoning had been due the solution of “The Mornington Crescent Mystery,” which, as all readers of this narrative will remember, for six months utterly perplexed Scotland Yard; while in a dozen other notable cases his discoveries had placed the police on the scent of the guilty person. Somehow he seemed to possess a peculiar facility in the solving of enigmas. At ordinary times he struck one as a rather careless, easy-going man, who drifted on through life, tasting and dealing in tea, with regular attendance at Mark Lane each day. Sometimes he wore a pair of cheap pince-nez, the frames of which were rusty, but these he seldom assumed unless he was what he termed “at work.” He was at work now, and therefore had stuck the pince-nez on the bridge of his nose, giving him a keener and rather more intelligent appearance.

“Excuse me,” he exclaimed, suddenly twisting his ring again round his finger. “I’ve just thought of something else. I won’t be a moment,” and he rushed from the library and ran upstairs to the floor above.

His absence gave me an opportunity to re-examine the little object which I had picked up from the floor at the earlier stages of the inquiry; and advancing to the window I took it from my pocket and looked again at it, utterly confounded.

Its appearance presented nothing extraordinary, for it was merely a soft piece of hard-knotted cream-coloured chenille about half-an-inch long. But sight of it lying in the palm of my hand held me spellbound in horror.

It told me the awful truth. It was nothing less than a portion of the fringe of the cream shawl which my love had been wearing, and just as chenille fringes will come to pieces, it had become detached and fallen where she had stood at that spot beside the victim’s bed.There was a smear of blood upon it.

I recollected her strangely nervous manner, her anxiety to ascertain what clue we had discovered and to know the opinion of the police. Yes, if guilt were ever written upon a woman’s face, it was upon hers.

Should I show the tiny fragment to my friend? Should I put it into his hands and tell him the bitter truth—the truth that I believed my love to be a murderess?