had contained a hint that they might involve intimate personal matters, and Harley was prepared to learn that the source of the distinguished surgeon's dread lay in some unrevealed episode of the past. Beyond the fact that Sir Charles was a widower, he knew little or nothing of his private life; and he was far too experienced an investigator to formulate theories until all the facts were in his possession. Therefore it was with keen interest that he looked forward to the interview.

Familiarity with crime, in its many complexions, East and West, had developed in Paul Harley a sort of sixth sense. It was an evasive, fickle thing, but was nevertheless the attribute which had made him an investigator of genius. Often enough it failed him entirely. It had failed him to-night—or else no one had followed him from Chancery Lane.

It had failed him earlier in the evening when, secretly, he had watched from the office window Sir Charles's car proceeding toward the Strand. That odd, sudden chill, as of an abrupt lowering of the temperature, which often advised him of the nearness of malignant activity, had not been experienced.

Now, standing before Sir Charles's house, he "sensed" the atmosphere keenly—seeking for the note of danger.

There had been a thunder shower just before he had set out, and now, although rain had ceased, the sky remained blackly overcast and a curious, dull stillness was come. The air had a welcome freshness and the glistening pavements looked delightfully cool after the parching heat of the day. In the quiet square, no doubt, it was always restful in contrast with the more busy highroads, and in the murmur of distant traffic he found something very soothing. About him then were peace, prosperity, and security.

Yet, as he stood there, waiting—it came to him: the note of danger. Swiftly he looked to right and left, trying to penetrate the premature dusk. The whole complexion of the matter changed. Some menace intangible now, but which at any moment might become evident—lay near him. It was sheer intuition, no doubt, but it convinced him.

A moment later he had rung the bell; and as a man opened the door, showing a easy and well-lighted lobby within, the fear aura no longer touched Paul Harley. Out from the doorway came hominess and that air of security and peace which had seemed to characterize the house when viewed from outside. The focus of menace, therefore, lay not inside the house of Sir Charles but without. It was very curious. In the next instant came a possible explanation.

"Mr. Paul Harley?" said the butler tentatively.

"Yes, I am he."

"Sir Charles is expecting you, sir. He apologizes for not being in to receive you, but he will only be absent a few minutes."

"Sir Charles has been called out?" inquired Harley as he handed hat and coat to the man.

"Yes, sir. He is attending Mr. Chester Wilson on the other side of the square, and Mr. Wilson's man rang up a few moments ago requesting Sir Charles to step across."

"I see," murmured Harley, as the butler showed him into a small but well-filled library on the left of the lobby.

Refreshments were set invitingly upon a table beside a deep lounge chair. But Harley declined the man's request to refresh himself while waiting and began aimlessly to wander about the room, apparently studying the titles of the works crowding the bookshelves. As a matter of fact, he was endeavouring to arrange certain ideas in order, and if he had been questioned on the subject it is improbable that he could have mentioned the title of one book in the library.

His mental equipment was of a character too rarely met with in the profession to which he belonged. While up to the very moment of reaching Sir Charles's house he had doubted the reality of the menace which hung over this man, the note of danger which he had sensed at the very threshold had convinced him, where more ordinary circumstantial evidence might have left him in doubt.

It was perhaps pure imagination, but experience had taught him that it was closely allied to clairvoyance.

Now upon his musing there suddenly intruded sounds of a muffled altercation. That is to say, the speakers, who were evidently in the lobby beyond the library door, spoke in low tones, perhaps in deference to the presence of a visitor. Harley was only mildly interested, but the voices had broken his train of thought, and when presently the door opened to admit a very neat but rather grim-looking old lady he started, then looked across at her with a smile.

Some of the grimness faded from the wrinkled old face, and the housekeeper, for this her appearance proclaimed her to be, bowed in a queer Victorian fashion which suggested that a curtsy might follow. One did not follow, however. "I am sure I apologize, sir," she said. "Benson did not tell me you had arrived."

"That's quite all right," said Harley, genially.

His smile held a hint of amusement, for in the comprehensive glance which the old lady cast across the library, a glance keen to detect disorder and from which no speck of dust could hope to conceal itself, there remained a trace of that grimness which he had detected at the moment of her entrance. In short, she was still bristling from a recent encounter. So much so that detecting something sympathetic in Harley's smile she availed herself of the presence of a badly arranged vase of flowers to linger and to air her grievances.

"Servants in these times," she informed him, her fingers busily rearranging the blooms, "are not what servants were in my young days."

"Unfortunately, that is so," Harley agreed.

The old lady tossed her head. "I do my best," she continued, "but that girl would not have stayed in the house for one week if I had had my way. Miss Phil is altogether too soft-hearted. Thank goodness, she goes to-morrow, though."

"You don't refer to Miss Phil?" said Harley, intentionally misunderstanding.

"Gracious goodness, no!" exclaimed the housekeeper, and laughed with simple glee at the joke. "I mean Jones, the new parlourmaid. When I say new, they are all new, for none of them stay longer than three months."

"Indeed," smiled Harley, who perceived that the old lady was something of a martinet.

"Indeed, they don't. Think they are ladies nowadays. Four hours off has that girl had to-day, although she was out on Wednesday. Then she has the impudence to allow someone to ring her up here at the house; and finally I discover her upsetting the table after Benson had laid it and after I had rearranged it."

She glanced indignantly in the direction of the lobby. "Perhaps one day," she concluded, pathetically, as she walked slowly from the room, "we shall find a parlourmaid who is a parlourmaid. Good evening, sir."

"Good evening," said Harley, quietly amused to be made the recipient of these domestic confidences.

He continued to smile for some time after the door had been closed. His former train of ideas was utterly destroyed, but for this he was not ungrateful to the housekeeper, since the outstanding disadvantage of that strange gift resembling prescience was that it sometimes blunted the purely analytical part of his mind when this should have been at its keenest. He was now prepared to listen to what Sir Charles had to say and to judge impartially of its evidential value.

Wandering from side to side of the library, he presently found himself standing still before the mantelpiece and studying a photograph in a silver frame which occupied the centre of the shelf. It was the photograph of an unusually pretty girl; that is to say, of a girl whose beauty was undeniable, but who belonged to a type widely removed from that of the ordinary good-looking Englishwoman.

The outline of her face was soft and charming, and there was a questioning look in her eyes which was alluring and challenging. Her naive expression was palpably a pose, and her slightly parted lips promised laughter. She possessed delightfully wavy hair and her neck and one shoulder,