"Naturally. But I hope you will soon learn to trust me," was his quiet retort. "I called you back to-night in order to see if you--my most intimate friend--would recognise me. But you do not. I am, therefore, safe--safe to go forth and perform a certain mission which it is imperative that I should perform."

"You are fooling me," I declared.

For a second he looked straight and unflinchingly into my eyes, then with a sudden movement he drew the left cuff of his dress shirt up to the elbow and held out his forearm for me to gaze upon.

I looked.

Then I stood dumbfounded, for half-way up the forearm, on the inside, was the cicatrice of an old knife wound which long ago, he had told me, had been made by an Indian in South America who had attempted to kill him, and whom he had shot in self-defence.

"You believe me now?" he asked, in a voice scarce above a whisper.

"Of course," I said. "Pardon me, Digby--but this change in your personality is marvellous--almost superhuman!"

"So I've been told before," he replied lightly.

"But, really, didn't you penetrate it?" he asked, resuming his normal voice.

"No. I certainly did not," I answered, and helping myself to a drink, swallowed it.

"Well?" I went on. "What does this mean?"

"At present I can't exactly tell you what I intend doing," he replied.

"To-night I wanted to test you, and have done so. It's late now," he added, glancing at the clock, which showed it to be half-past two o'clock in the morning. "Come in to-morrow at ten, will you?" he asked. "I want to discuss the future with you very seriously. I have something to say which concerns your own future, and which also closely concerns a friend of yours. So come in your own interests, Royle--now don't fail, I beg of you!"

"But can't you tell me to-night," I asked.

"Not until I know something of what my own movements are to be," he replied. "I cannot know before to-morrow," he replied with a mysterious air. "So if you wish to be forewarned of an impending peril, come and see me and I will then explain. We shall, no doubt, be on closer terms to-morrow. _Au revoir_," and he took my hand warmly and then let me out.

The rather narrow, ill-lit staircase, the outer door of which had been shut for hours, was close and stuffy, but as I descended the second flight and was about to pa.s.s along the hall to the door, I distinctly heard a movement in the shadow where, on my left, the hall continued along to the door of the ground-floor flat.

I peered over the banisters, but in the darkness could distinguish nothing.

That somebody was lurking there I instantly felt a.s.sured, and next moment the truth became revealed by two facts.

The first was a light, almost imperceptible noise, the jingle of a woman's bangles, and, secondly, the faint odour of some subtle perfume, a sweet, intoxicating scent such as my nostrils had never greeted before.

For the moment I felt surprise, but as the hidden lady was apparently standing outside the ground-floor flat--perhaps awaiting admittance--I felt it to be no concern of mine, and proceeding, opened the outer door and pa.s.sed outside, closing it quietly after me.

An unusually sweet perfume one can seldom forget. Even out in the keen night air that delightful odour seemed to cling to my memory--the latest creation of the Rue de la Paix, I supposed.

Well, I duly returned home to Albemarle Street once again, utterly mystified.

What did it all mean? Why had Digby adopted such a marvellous disguise?

What did he mean by saying that he wished to stand my friend and safeguard me from impending evil?

Yes, it was all a mystery--but surely not so great a mystery as that which was to follow. Ah! had I but suspected the astounding truth how very differently would I have acted!

Filled with curiosity regarding Digby's strange forebodings, I alighted from a taxi in Harrington Gardens at a quarter to eleven that same morning, but on entering found the uniformed hall-porter in a great state of excitement and alarm.

"Oh, sir!" he cried breathlessly, advancing towards me. "You're a friend of Sir Digby's sir. The police are upstairs. Something extraordinary has happened."

"The police!" I gasped. "Why, what's happened?"

"Well, sir. As his man left the day before yesterday, my wife went up to Sir Digby's flat as usual this morning about eight, and put him his early cup of tea outside his door. But when she went in again she found he had not taken it into his room. She believed him to be asleep, so not till ten o'clock did she go into the sitting-room to draw up the blinds, when, to her horror, she found a young lady, a perfect stranger, lying stretched on the floor there! She rushed down and told me, and I went up.

I found that Sir Digby's bed hadn't been slept in, and that though the poor girl was unconscious, she was still breathing. So I at once called in the constable on point duty at the corner of Collingham Road, and he 'phoned to the police station."

"But the girl--is she dead?" I inquired quickly.

"I don't know, sir. You'd better go upstairs. There's an inspector, two plain-clothes men, and a doctor up there."

He took me up in the lift, and a few moments later I stood beside Digby's bed, whereon the men had laid the inanimate form of a well-dressed girl whom I judged to be about twenty-two, whose dark hair, unbound, lay in disorder upon the pillow. The face, white as marble, was handsome and clean cut, but upon it, alas! was the ashen hue of death, the pale lips slightly parted as though in a half-sarcastic smile.

The doctor was bending over her making his examination.

I looked upon her for a moment, but it was a countenance which I had never seen before. Digby had many lady friends, but I had never seen her among them. She was a perfect stranger.

Her gown was of dark blue serge, smartly made, and beneath her coat she wore a cream silk blouse with deep sailor collar open at the neck, and a soft flowing bow of turquoise blue. This, however, had been disarranged by the doctor in opening her blouse to listen to her breathing, and I saw that upon it was a small crimson stain.

Yes, she was remarkably good-looking, without a doubt.

When I announced myself as an intimate friend of Sir Digby Kemsley, the inspector at once took me into the adjoining room and began to eagerly question me.

With him I was perfectly frank; but I said nothing regarding my second visit there in the night.

My gravest concern was the whereabouts of my friend.

"This is a very curious case, Mr. Royle," declared the inspector. "The C.I.D. men have established one fact--that another woman was with the stranger here in the early hours of this morning. This hair-comb"--and he showed me a small side-comb of dark green horn--"was found close beside her on the floor. Also a couple of hair-pins, which are different to those in the dead woman's hair. There was a struggle, no doubt, and the woman got away. In the poor girl's hair are two tortoisesh.e.l.l side-combs."

"But what is her injury?" I asked breathlessly.

"She's been stabbed," he replied. "Let's go back."

Together we re-entered the room, but as we did so we saw that the doctor had now left the bedside, and was speaking earnestly with the two detectives.

"Well, doctor?" asked the inspector in a low voice.

"She's quite dead--murder, without a doubt," was his reply. "The girl was struck beneath the left breast--a small punctured wound, but fatal!"

"The woman who left this hair-comb behind knows something about the affair evidently," exclaimed the inspector. "We must first discover Sir Digby Kemsley. He seems to have been here up until eleven o'clock last night. Then he mysteriously disappeared, and the stranger entered unseen, two very curious and suspicious circ.u.mstances. I wonder who the poor girl was?"

The two detectives were discussing the affair in low voices. Here was a complete and very remarkable mystery, which, from the first, the police told me they intended to keep to themselves, and not allow a syllable of it to leak out to the public through the newspapers.

A woman had been there!

Did there not exist vividly in my recollection that strange encounter in the darkness of the stairs? The jingle of the golden bangles, and the sweet odour of that delicious perfume?

But I said nothing. I intended that the police should prosecute their inquiries, find my friend, and establish the ident.i.ty of the mysterious girl who had met with such an untimely end presumably at the hands of that woman who had been lurking in the darkness awaiting my departure.

Truly it was a mystery, a most remarkable problem among the many which occur each week amid the amazing labyrinth of humanity which we term London life.