I drove Phrida back to Cromwell Road in a taxi.

As I sat beside her, that sweet irritating perfume filled my senses, almost intoxicating me. For some time I remained silent; then, unable to longer restrain my curiosity, I exclaimed with a calm, irresponsible air, though with great difficulty of self-restraint:

"What awfully nice perfume you have, dearest! Surely it's new, isn't it? I never remember smelling it before!"

"Quite new, and rather delicious, don't you think? My cousin Arthur brought it from Paris a few days ago. I only opened the bottle last night. Mother declared it to be the sweetest she's ever smelt. It's so very strong that one single drop is sufficient."

"What do they call it?"

"Parfait d'Amour. Lauzan, in the PlacÉ VendÔme, makes it. It's quite new, and not yet on the market, Arthur said. He got it—a sample bottle—from a friend of his in the perfume trade."

Not on the market! Those words of hers condemned her. Little did she dream that I had smelt that same sweet, subtle odour as I descended the stairs from Sir Digby's flat. She, no doubt, had recognised my silhouette in the half darkness, yet nevertheless she felt herself quite safe, knowing that I had not seen her.

Why had she been lurking there?

A black cloud of suspicion fell upon me. She kept up a desultory conversation as we went along Piccadilly in the dreary gloom of that dull January afternoon, but I only replied in monosyllables, until at length she remarked:

"Really, Teddy, you're not thinking of a word I'm saying. I suppose your mind is centred upon your friend—the man who has turned out to be an impostor."

The conclusion of that sentence and its tone showed a distinct antagonism.

It was true that the man whom I had known as Sir Digby Kemsley—the man who for years past had been so popular among a really good set in London—was according to the police an impostor.

The detective-inspector had told me so. From the flat in Harrington Gardens the men of the Criminal Investigation Department had rung up New Scotland Yard to make their report, and about noon, while I was resting at home in Albemarle Street, I was told over the telephone that my whilom friend was not the man I had believed him to be.

As I had listened to the inspector's voice, I heard him say:

"There's another complication of this affair, Mr. Royle. Your friend could not have been Sir Digby Kemsley, for that gentleman died suddenly a year ago, at Huacho, in Peru. There was some mystery about his death, it seems, for it was reported by the British Consul at Lima. Inspector Edwards, of the C.I. Department, will call upon you this afternoon. What time could you conveniently be at home?"

I named five o'clock, and that appointment I intended, at all hazards, to keep.

The big, heavily-furnished drawing-room in Cromwell Road was dark and sombre as I stood with Phrida, who, bright and happy, pulled off her gloves and declared to her mother—that charming, sedate, grey-haired, but wonderfully preserved, woman—that she had had such "a jolly lunch."

"I saw the Redmaynes there, mother," she was saying. "Mr. Redmayne has asked us to lunch with them at the Carlton next Tuesday. Can we go?"

"I think so, dear," was her mother's reply. "I'll look at my engagements."

"Oh, do let's go! Ida is coming home from her trip to the West Indies. I do want to see her so much."

Strange it was that my well-beloved, in face of that amazing mystery, preserved such an extraordinary, nay, an astounding, calm. I was thinking of the little side-comb of green horn, for I had seen her wearing a pair exactly similar!

Standing by I watched her pale sweet countenance, full of speechless wonder.

After the first moment of suspense she had found herself treading firm ground, and now, feeling herself perfectly secure, she had assumed a perfectly frank and confident attitude.

Yet the perfume still arose to my nostrils—the sweet, subtle scent which had condemned her.

I briefly related to Mrs. Shand my amazing adventures of the previous night, my eyes furtively upon Phrida's countenance the while. Strangely enough, she betrayed no guilty knowledge, but fell to discussing the mystery with ease and common-sense calm.

"What I can't really make out is how your friend could have had the audacity to pose as Sir Digby Kemsley, well knowing that the real person was alive," she remarked.

"The police have discovered that Sir Digby died in Peru last January," I said.

"While your friend was in London?"

"Certainly. My friend—I shall still call him Sir Digby, for I have known him by no other name—has not been abroad since last July, when he went on business to Moscow."

"How very extraordinary," remarked Mrs. Shand. "Your friend must surely have had some object in posing as the dead man."

"But he posed as a man who was still alive!" I exclaimed.

"Until, perhaps, he was found out," observed Phrida shrewdly. "Then he bolted."

I glanced at her quickly. Did those words betray any knowledge of the truth, I wondered.

"Apparently there was some mystery surrounding the death of Sir Digby at Huacho," I remarked. "The British Consul in Lima made a report upon it to the Foreign Office, who, in turn, handed it to Scotland Yard. I wonder what it was."

"When you know, we shall be better able to judge the matter and to form some theory," Phrida said, crossing the room and re-arranging the big bowl of daffodils in the window.

I remained about an hour, and then, amazed at the calmness of my well-beloved, I returned to my rooms.

In impatience I waited till a quarter past five, when Haines ushered in a tall, well-dressed, clean-shaven man, wearing a dark grey overcoat and white slip beneath his waistcoat, and who introduced himself as Inspector Charles Edwards.

"I've called, Mr. Royle, in order to make some further inquiries regarding this person you have known as Sir Digby Kemsley," he said when he had seated himself. "A very curious affair happened last night. I've been down to Harrington Gardens, and have had a look around there myself. Many features of the affair are unique."

"Yes," I agreed. "It is curious—very curious."

"I have a copy of your statement regarding your visit to the house during the night," said the official, who was one of the Council of Seven at the Yard, looking up at me suddenly from the cigarette he was about to light. "Have you any suspicion who killed the young lady?"

"How can I have—except that my friend——"

"Is missing—eh?"

"Exactly."

"But now, tell me all about this friend whom you knew as Sir Digby Kemsley. How did you first become acquainted with him?"

"I met him on a steamer on the Lake of Garda this last summer," was my reply. "I was staying at Riva, the little town at the north end of the lake, over the Austrian frontier, and one day took the steamer down to Gardone, in Italy. We sat next each other at lunch on board, and, owing to a chance conversation, became friends."

"What did he tell you?"

"Well, only that he was travelling for his health. He mentioned that he had been a great deal in South America, and was then over in Europe for a holiday. Indeed, on the first day we met, he did not even mention his name, and I quite forgot to ask for it. In travelling one meets so many people who are only of brief passing interest. It was not until a week later, when I found him staying in the same hotel as myself, the Cavour, in Milan, I learnt from the hall-porter that he was Sir Digby Kemsley, the great engineer. We travelled to Florence together, and stayed at the Baglioni, but one morning when I came down I found a hurried note awaiting me. From the hall-porter I learned that a gentleman had arrived in the middle of the night, and Sir Digby, after an excited controversy, left with him for London. In the note he gave me his address in Harrington Gardens, and asked me not to fail to call on my return to town."

"Curious to have a visitor in the middle of the night," remarked the detective reflectively.

"I thought so at the time, but, knowing him to be a man of wide business interests, concluded that it was someone who had brought him an urgent message," I replied. "Well, the rest is quickly told. On my return home I sought him out, with the result that we became great friends."

"You had no suspicion that he was an impostor?"

"None whatever. He seemed well known in London," I replied. "Besides, if he was not the real Sir Digby, how is it possible that he could have so completely deceived his friends! Why, he has visited the offices of Colliers, the great railway contractors in Westminster—the firm who constructed the railway in Peru. I recollect calling there with him in a taxi one day."

Edwards smiled.

"He probably did that to impress you, sir," he replied. "They may have known him as somebody else. Or he simply went in and made an inquiry. He's evidently a very clever person."

Personally, I could not see how my friend could possibly have posed as Sir Digby Kemsley if he were not, even though Edwards pointed out that the real Sir Digby had only been in London a fortnight for the past nine years.

Still, on viewing the whole situation, I confess inclination towards the belief that my friend was, notwithstanding the allegations, the real Sir Digby.

And yet those strange words of his, spoken in such confidence on the previous night, recurred to me. There was mystery somewhere—a far more obscure mystery even than what was apparent at that moment.

"Tell me what is known concerning Sir Digby's death in Peru," I asked.

"From the report furnished to us at the Yard it seems that one day last August, while the gentleman in question was riding upon a trolley on the Cerro de Pasco railway, the conveyance was accidentally overturned into a river, and he was badly injured in the spine. A friend of his, a somewhat mysterious Englishman named Cane, brought him down to the hospital at Lima, and after two months there, he becoming convalescent, was conveyed for fresh air to Huacho, on the sea. Here he lived with Cane in a small bungalow in a somewhat retired spot, until on one night in February last year something occurred—but exactly what, nobody is able to tell. Sir Digby was found by his Peruvian servant dead from snake-bite. Cane evinced the greatest distress and horror until, of a sudden, a second man-servant declared that he had heard his master cry out in terror as he lay helpless in his bed. He heard him shriek: 'You—you blackguard, Cane—take the thing away! Ah! God! You've—you've killed me!' Cane denied it, and proved that he was at a friend's house playing cards at the hour when the servant heard his master shout for help. Next day, however, he disappeared. Our Consul in Lima took up the matter, and in due course a full report of the affair was forwarded to the Yard, together with a very detailed description of the man wanted. This we sent around the world, but up to to-day without result."

"Then the man Cane was apparently responsible for the death of the invalid," I remarked.

"I think so—without a doubt."

"But who was the invalid? Was he the real Sir Digby?"

"Aye, that's the question," said Edwards, thrusting his hands into his trouser pockets. For some moments we both sat staring blankly into the fire.

"Among the papers sent to us," he said very slowly at last, "was this. Read it, and tell me your opinion."

And then he took from his pocket-book and handed me a half-sheet of thin foreign notepaper, which had been closely written upon on both sides. It was apparently a sheet from a letter, for there was no beginning and no ending.

The handwriting was educated, though small and crabbed, and the ink brown and half-faded, perhaps because of its exposure to a tropical climate. It had been written by a man, without a doubt.

"That," said Edwards, "was found in a pocket-book belonging to Cane, which, in his hasty flight, he apparently forgot. According to our report the wallet was found concealed beneath the mattress of his bed, as though he feared lest anyone should read and learn what it contained. Read it, and tell me what you think."

I took the sheet of thin paper in my fingers, and, crossing the room to a brighter light, managed to decipher the writing as follows:

"... At fourteen paces from where this wall rises from the lawn stands the ever-plashing fountain. The basin is circular, while around runs a paved path, hemmed in by smoke-blackened laurels and cut off from the public way by iron railings. The water falls with pleasant cadence into a small basin set upon a base of moss-grown rockwork. Looking south one meets a vista of green grass, of never-ceasing London traffic, and one tall distant factory chimney away in the grey haze, while around the fountain are four stunted trees. On the right stretches a strip of garden, in spring green and gay with bulbs which bloom and die unnoticed by the hundreds upon hundreds of London's workers who pass and re-pass daily in their mad, reckless hurry to earn the wherewithal to live.

"Halt upon the gravel at that spot on the twenty-third of the month punctually at noon, and she will pass wearing the yellow flower. It is the only trysting-place. She has kept it religiously for one whole year without—alas!—effecting a meeting. Go there—tell her that I still live, shake her hand in greeting and assure her that I will come there as soon as ever I am given strength so to do.

"I have been at that spot once only, yet every detail of its appearance is impressed indelibly upon my memory. Alas! that I do not know its name. Search and you will assuredly find it—and you will see her. You will speak, and give her courage."