the shadow of some trees, and beyond the fact that my assailant was a small man, I could form no impression of his identity."

"What did you do?"

"I turned and struck out with my stick."

"And then?"

"Then he made no attempt to contest the issue, but simply ran swiftly off, always keeping in the shadows of the trees."

"Very strange," murmured Harley. "Do you think he had meant to drug you?"

"Maybe," replied Sir Charles. "The handkerchief was perhaps saturated with some drug, or he may even have designed to attempt to strangle me."

"And you formed absolutely no impression of the man?"

"None whatever, Mr. Harley. When you see the spot at which the encounter took place, if you care to do so, you will recognize the difficulties. It is perfectly dark there after nightfall."

"H'm," mused Harley. "A very alarming occurrence, Sir Charles. It must have shaken you very badly. But we must not overlook the possibility that this may have been an ordinary footpad."

"His methods were scarcely those of a footpad," murmured Sir Charles.

"I quite agree," said Harley. "They were rather Oriental, if I may say so."

Sir Charles Abingdon started. "Oriental!" he whispered. "Yes, you are right."

"Does this suggest a train of thought?" prompted Harley.

Sir Charles Abingdon cleared his throat nervously. "It does, Mr. Harley," he admitted, "but a very confusing train of thought. It leads me to a point which I must mention, but which concerns a very well-known man. Before I proceed I should like to make it clear that I do not believe for a moment that he is responsible for this unpleasant business."

Harley stared at him curiously. "Nevertheless," he said, "there must be some data in your possession which suggest to your mind that he has some connection with it."

"There are, Mr. Harley, and I should be deeply indebted if you could visit my house this evening, when I could place this evidence, if evidence it may be called, before you. I find myself in so delicate a position. If you are free I should welcome your company at dinner."

Paul Harley seemed to be reflecting.

"Of course, Sir Charles," he said, presently, "your statement is very interesting and curious, and I shall naturally make a point of going fully into the matter. But before proceeding further there are two questions I should like to ask you. The first is this: What is the name of the 'well-known' man to whom you refer? And the second: If not he then whom do you suspect of being behind all this?"

"The one matter is so hopelessly involved in the other," he finally replied, "that although I came here prepared as I thought with a full statement of the case, I should welcome a further opportunity of rearranging the facts before imparting them to you. One thing, however, I have omitted to mention. It is, perhaps, of paramount importance. There was a robbery at my house less than a week ago."

"What! A robbery! Tell me: what was stolen?"

"Nothing of the slightest value, Mr. Harley, to any one but myself—or so I should have supposed." The speaker coughed nervously. "The thief had gained admittance to my private study, where there are several cases of Oriental jewellery and a number of pieces of valuable gold and silverware, all antique. At what hour he came, how he gained admittance, and how he retired, I cannot imagine. All the doors were locked as usual in the morning and nothing was disturbed."

"I don't understand, then."

"I chanced to have occasion to open my bureau which I invariably keep locked. Immediately—immediately—I perceived that my papers were disarranged. Close examination revealed the fact that a short manuscript in my own hand, which had been placed in one of the pigeonholes, was missing."

"A manuscript," murmured Harley. "Upon a technical subject?"

"Scarcely a technical subject, Mr. Harley. It was a brief account which I had vaguely contemplated publishing in one of the reviews, a brief account of a very extraordinary patient whom I once attended."

"And had you written it recently?"

"No; some years ago. But I had recently added to it. I may say that it was my purpose still further to add to it, and with this object I had actually unlocked the bureau."

"New facts respecting this patient had come into your possession?"

"They had."

"Before the date of the attack upon you?"

"Before that date, yes."

"And before surveillance of your movements began?"

"I believe so."

"May I suggest that your patient and the 'well-known man' to whom you referred are one and the same?"

"It is not so, Mr. Harley," returned Sir Charles in a tired voice. "Nothing so simple. I realize more than ever that I must arrange my facts in some sort of historical order. Therefore I ask you again: will you dine with me to-night?"

"With pleasure," replied Harley, promptly. "I have no other engagement."

That his ready acceptance had immensely relieved the troubled mind of Sir Charles was evident enough. His visitor stood up. "I am not prone to sickly fancies, Mr. Harley," he said. "But a conviction has been growing upon me for some time that I have incurred, how I cannot imagine, but that nevertheless I have incurred powerful enmity. I trust our evening's counsel may enable you, with your highly specialized faculties, to detect an explanation."

And it was instructive to note how fluently he spoke now that he found himself temporarily relieved of the necessity of confessing the source of his mysterious fears.

CHAPTER II. THE SIXTH SENSE

Paul Harley stepped into his car in Chancery Lane. "Drive in the direction of Hyde Park Corner," he directed the chauffeur. "Go along the Strand."

Glancing neither right nor left, he entered the car, and presently they were proceeding slowly with the stream of traffic in the Strand. "Pull up at the Savoy," he said suddenly through the tube.

The car slowed down in that little bay which contains the entrance to the hotel, and Harley stared fixedly out of the rear window, observing the occupants of all other cars and cabs which were following. For three minutes or more he remained there watching. "Go on," he directed.

Again they proceeded westward and, half-way along Piccadilly, "Stop at the Ritz," came the order.

The car pulled up before the colonnade and Harley, stepping out, dismissed the man and entered the hotel, walked through to the side entrance, and directed a porter to get him a taxicab. In this he proceeded to the house of Sir Charles Abingdon. He had been seeking to learn whether he was followed, but in none of the faces he had scrutinized had he detected any interest in himself, so that his idea that whoever was watching Sir Charles in all probability would have transferred attention to himself remained no more than an idea. For all he had gained by his tactics, Sir Charles's theory might be no more than a delusion after all.

The house of Sir Charles Abingdon was one of those small, discreet establishments, the very neatness of whose appointments inspires respect for the occupant. If anything had occurred during the journey to suggest to Harley that Sir Charles was indeed under observation by a hidden enemy, the suave British security and prosperity of his residence must have destroyed the impression.

As the cab was driven away around the corner, Harley paused for a moment, glancing about him to right and left and up at the neatly curtained windows. In the interval which had elapsed since Sir Charles's departure from his office, he had had leisure to survey the outstanding features of the story, and, discounting in his absence the pathetic sincerity of the narrator, he had formed the opinion that there was nothing in the account which was not susceptible of an ordinary prosaic explanation.

Sir Charles's hesitancy in regard to two of the questions asked