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.