Sir Charles slowly nodded his head, and seemed in some measure to recover confidence.

“Briefly, then,” he said, “I believe my life is in danger.”

“You mean that there is someone who desires your death?”

“I do.”

“H’m,” said Harley, replacing the tin in the cupboard and striking a match.  “Even if the facts are scanty, no doubt you have fairly substantial grounds for such a suspicion?”

“I cannot say that they are substantial, Mr. Harley.  They are rather more circumstantial.  Frankly, I have forced myself to come here, and now that I have intruded upon your privacy, I realize my difficulties more keenly than ever.”

The expression of embarrassment upon the speaker’s face had grown intense; and now he paused, bending forward in his chair.  He seemed in his glance to appeal for patience on the part of his hearer, and Harley, lighting his pipe, nodded in understanding fashion.  He was the last man in the world to jump to conclusions.  He had learned by bitter experience that lightly to dismiss such cases as this of Sir Charles as coming within the province of delusion, was sometimes tantamount to refusing aid to a man in deadly peril.

“You are naturally anxious for the particulars,” Sir Charles presently resumed.  “They bear, I regret to say, a close resemblance to the symptoms of a well-known form of hallucination.  In short, with one exception, they may practically all be classed under the head of surveillance.”

“Surveillance,” said Paul Harley.  “You mean that you are more or less constantly followed?”

“I do.”

“And what is your impression of this follower?”

“A very hazy one.  To-night, as I came to your office, I have every reason to believe that someone followed me in a taxicab.”

“You came in a car?”

“I did.”

“And a cab followed you the whole way?”

“Practically the whole way, except that as my chauffeur turned into Chancery Lane, the cab stopped at the corner of Fleet Street.”

“Your idea is that your pursuer followed on foot from this point?”

“Such was my impression.”

“H’m, quite impossible.  And is this sort of thing constant, Sir Charles?”

“It has been for some time past.”

“Anything else?”

“One very notable thing, Mr. Harley.  I was actually assaulted less than a week ago within sight of my own house.”

“Indeed!  Tell me of this.”  Paul Harley became aware of an awakening curiosity.  Sir Charles Abingdon was not the type of man who is lightly intimidated.

“I had been to visit a friend in the neighbourhood,” Sir Charles continued, “whom I am at present attending professionally, although I am actually retired.  I was returning across the square, close to midnight, when, fortunately for myself, I detected the sound of light, pattering footsteps immediately behind me.  The place was quite deserted at that hour, and although I was so near home, the worst would have happened, I fear, if my sense of hearing had been less acute.  I turned in the very instant that a man was about to spring upon me from behind.  He was holding in his hand what looked like a large silk handkerchief.  This encounter took place in the shadow of some trees, and beyond the fact that my assailant was a small man, I could form no impression of his identity.”