The night of my mysterious tryst—the night of January the fourteenth—was dark, rainy, and unpleasant.

That afternoon I had taken out the sealed letter addressed to "E. P. K." and turned it over thoughtfully in my hand.

I recollected the words of the fugitive. He had said:

"On the night of the fourteenth just at eight o'clock precisely, go to the Piccadilly Tube Station and stand at the first telephone box numbered four, on the Haymarket side, when a lady in black will approach you and ask news of me. In response you will give her this note. But there is a further condition. You may be watched and recognised. Therefore, be extremely careful that you are not followed on that day, and, above all, adopt some effective disguise. Go there dressed as a working man, I would suggest."

Very strange was that request of his. It filled me with eager curiosity. What should I learn from the mysterious woman in black who was to come to me for a message from my fugitive friend.

Had he already contemplated flight when he had addressed the note to her and made the appointment, I wondered.

If so, the crime at Harrington Gardens must have been premeditated.

I recollected, too, those strange, prophetic words which my friend had afterwards uttered, namely:

"I want you to give me your promise, Royle. I ask you to make a solemn vow to me that if any suspicion arises within your mind, that you will believe nothing without absolute and decisive proof. I mean, that you will not misjudge her."

By "her" he had indicated the lady whose initials were "E. P. K."

It was certainly mysterious, and my whole mind was centred upon the affair that day.

As I stood before my glass at seven o'clock that evening, I presented a strange, uncanny figure, dressed as I was in a shabby suit which I had obtained during the day from a theatrical costumier's in Covent Garden.

Haines, to whom I had invented a story that I was about to play a practical joke, stood by much amused at my appearance.

"Well, sir," he exclaimed; "you look just like a bricklayer's labourer!"

The faded suit, frayed at the wrists and elbows, had once been grey, but it was now patched, brown, smeared with plaster, and ingrained with white dust, as was the ragged cap; while the trousers were ragged at the knees and bottoms. Around my neck was a dirty white scarf and in my hand I carried a tin tea-bottle as though I had just returned from work.

"Yes," I remarked, regarding myself critically. "Not even Miss Shand would recognise me—eh, Haines?"

"No, sir. I'm sure she wouldn't. But you'll have to dirty your face and hands a bit. Your hands will give you away if you're not careful."

"Yes. I can't wear gloves, can I?" I remarked.

Thereupon, I went to the grate and succeeded in rubbing ashes over my hands and applying some of it to my cheeks—hardly a pleasant face powder, I can assure you.

At a quarter to eight, with the precious letter in the pocket of my ragged jacket, I left Albemarle Street and sauntered along Piccadilly towards the Circus. The rain had ceased, but it was wet underfoot, and the motor buses plashed foot passengers from head to foot with liquid mud. In my walk I passed, outside the Piccadilly Hotel, two men I knew. One of them looked me straight in the face but failed to recognise me.

Piccadilly Circus, the centre of the night-life of London, is unique, with its jostling crowds on pleasure bent, its congestion of traffic, its myriad lights, its flashing, illuminated signs, and the bright faÇade of the Criterion on the one side and the Pavilion on the other. Surely one sees the lure of London there more than at any other spot in the whole of our great metropolis.

Passing the Criterion and turning into the Haymarket, I halted for a moment on the kerb, and for the first time in my life, perhaps, gazed philosophically upon the frantic, hurrying panorama of human life passing before my eyes.

From where I stood I could see into the well-lit station entrance with the row to the telephone boxes, at the end of which sat the smart young operator, who was getting numbers and collecting fees. All the boxes were engaged, and several persons were waiting, but in vain my eyes searched for a lady in black wearing mimosa.

The winter wind was bitterly cold, and as I was without an overcoat it cut through my thin, shabby clothes, causing me to shiver. Nevertheless, I kept my watchful vigil. By a neighbouring clock I could see that it was already five minutes past the hour of the appointment. Still, I waited in eager expectation of her coming.

The only other person who seemed to loiter there was a thin, shivering Oriental, who bore some rugs upon his shoulder—a hawker of shawls.

Past me there went men and women of every grade and every station. Boys were crying "Extrur spe-shull," and evil-looking loafers, those foreign scoundrels who infest the West End, lurked about, sometimes casting a suspicious glance at me, with the thought, perhaps, that I might be a detective.

Ah! the phantasmagora of life outside the Piccadilly Tube at eight o'clock in the evening is indeed a strangely complex one. The world of London has then ceased to work and has given itself over to pleasure, and, alas! in so many cases, to evil.

In patience I waited. The moments seemed hours, for in my suspense I was dubious whether, after all, she would appear. Perhaps she already knew, by some secret means, of Sir Digby's flight, and if so, she would not keep the appointment.

I strolled up and down the pavement, for a policeman, noticing me hanging about, had gruffly ordered me to "Move on!" He, perhaps, suspected me of "loitering for the purpose of committing a felony."

Everywhere my eager eyes searched to catch sight of some person in black wearing a spray of yellow blossom, but among that hurrying crowd there was not one woman, young or old, wearing that flower so reminiscent of the Riviera.

I entered the station, and for some moments stood outside the telephone box numbered 4. Then, with failing heart, I turned and went along to the spacious booking-hall, where the lifts were ever descending with their crowds of passengers.

Would she ever come? Or, was my carefully planned errand entirely in vain?

I could not have mistaken the date, for I had made a note of it in my diary directly on my return from Harrington Gardens, and before I had learned of the tragedy. No. It now wanted a quarter to nine and she had not appeared. At nine I would relinquish my vigil, and assume my normal identity. I was sick to death of lounging there in the cutting east wind with the smoke-blackened tin bottle in my hand.

I had been idly reading an advertisement on the wall, and turned, when my quick eyes suddenly caught sight of a tall, well-dressed woman of middle age, who, standing with her back to me, was speaking to the telephone-operator.

I hurried eagerly past her, when my heart gave a great bound. In the corsage of her fur-trimmed coat she wore the sign for which I had been searching for an hour—a sprig of mimosa!

With my heart beating quickly in wild excitement, I drew back to watch her movements.

She had asked the operator for a number, paid him, and was told that she was "on" at box No. 4.

I saw her enter, and watched her through the glass door speaking vehemently with some gesticulation. The answer she received over the wire seemed to cause her the greatest surprise, for I saw how her dark, handsome face fell when she heard the response.

In a second her manner changed. From a bold, commanding attitude she at once became apprehensive and appealing. Though I could not hear the words amid all that hubbub and noise, I knew that she was begging the person at the other end to tell her something, but was being met with a flat refusal.

I saw how the black-gloved hand, resting upon the little ledge, clenched itself tightly as she listened. I fancied that tears had come into her big, dark eyes, but perhaps it was only my imagination.

At last she put down the receiver and emerged from the box, with a strange look of despair upon her handsome countenance.

What, I wondered, had happened?

She halted outside the box for a moment, gazing about her as though in expectation of meeting someone. She saw me, but seeing only a labourer, took no heed of my presence. Then she glanced at the tiny gold watch in her bracelet, and noting that it was just upon nine, drew a long breath—a sigh as though of despair.

I waited until she slowly walked out towards the street, and following, came up beside her and said in a low voice:

"I wonder, madame, if you are looking for me?"

She glanced at me quickly, with distinct suspicion, and noting my dress, regarded me with some disdain.

Her dark brows were knit for a second in distinct displeasure, even of apprehension, and then in an instant I recollected my friend's injunction that I might be watched and followed. In giving her the message the greatest secrecy was to be observed.

She halted, as though in hesitation, took from her bag a tiny lace handkerchief and dabbed her face, then beneath her breath, and without glancing further at me, said:

"Follow me, and I will speak to you presently—when there is no danger."

Upon that I moved away and leisurely lit my pipe, as though entirely unconcerned, while she still stood in the doorway leading to the Haymarket, looking up and down as though awaiting somebody.

Yes, she was a distinctly handsome woman; tall, erect, and well preserved. Her gown fitted her perfectly, and her black jacket, trimmed with some rich dark fur, was a garment which gave her the stamp of a woman of wealth and refinement. She wore a neat felt hat also trimmed with fur, white gloves, and smart shoes, extremely small, even girlish, for a woman so well developed.

Presently she sauntered forth down the Haymarket, and a few moments afterwards, still smoking and carrying my bottle, I lounged lazily after her.

At the corner, by the Carlton, she turned into Pall Mall, continuing along that thoroughfare without once looking back. Opposite the United Service Club she crossed the road, and passing across the square in front of the AthenÆum, descended the long flight of steps which led into the Mall.

There in the darkness, beneath the trees, where there were no onlookers—for at that hour the Mall is practically deserted, save for a few loving couples and a stray taxi or two—she suddenly paused, and I quickly approached and raised my cap politely.

"Well?" she asked sharply, almost in a tone of annoyance. "What is it? What do you want with me, my man?"