Some of Paul Harley’s most interesting cases were brought to his notice in an almost accidental way.  Although he closed his office in Chancery Lane sharply at the hour of six, the hour of six by no means marked the end of his business day.  His work was practically ceaseless.  But even in times of leisure, at the club or theatre, fate would sometimes cast in his path the first slender thread which was ultimately to lead him into some unsuspected labyrinth, perhaps in the underworld of London, perhaps in a city of the Far East.

His investigation of the case of the man with the shaven skull afforded an instance of this, and even more notable was his first meeting with Major Jack Ragstaff of the Cavalry Club, a meeting which took place after the office had been closed, but which led to the unmasking of perhaps the most cunning murderer in the annals of crime.

One summer’s evening when the little clock upon his table was rapidly approaching the much-desired hour, Harley lay back in his chair and stared meditatively across his private office in the direction of a large and very handsome Burmese cabinet, which seemed strangely out of place amid the filing drawers, bookshelves, and other usual impedimenta of a professional man.  A peculiarly uninteresting week was drawing to a close, and he was wondering if this betokened a decreased activity in the higher criminal circles, or whether it was merely one of those usual quiescent periods which characterize every form of warfare.

Paul Harley, although the fact was unknown to the general public, occupied something of the position of an unofficial field marshal of the forces arrayed against evildoers.  Throughout the war he had undertaken confidential work of the highest importance, especially in regard to the Near East, with which he was intimately acquainted.  A member of the English bar, and the last court of appeal to which Home Office and Foreign Office alike came in troubled times, the brass plate upon the door of his unassuming premises in Chancery Lane conveyed little or nothing to the uninitiated.

The man himself, with his tropical bronze and air of eager vitality, must have told the most careless observer that he stood in the presence of an extraordinary personality.  He was slightly gray at the temples in these days, but young in mind and body, physically fit, and possessed of an intellectual keenness which had forced recognition from two hemispheres.  His office was part of an old city residence, and his chambers adjoined his workroom, so that now, noting that his table clock registered the hour of six, he pressed a bell which summoned Innes, his confidential secretary.

“Well, Innes,” said Harley, looking around, “another uneventful day.”

“Very uneventful, Mr. Harley.  About a month of this and you will have to resume practice at the bar.”

Paul Harley laughed.

“Not a bit likely, Innes,” he replied.  “No more briefs for me.  I shall retire to Norfolk and devote my declining years to fishing.”

“I don’t know that fishing would entirely satisfy me,” said Innes.

“It would more than satisfy me,” returned Harley.  “But every man to his own ambition.  Well, there is no occasion to wait; you might as well get along.  But what’s that you’ve got in your hand?”

“Well,” replied Innes, laying a card upon the table, “I was just coming in with it when you rang.”

Paul Harley glanced at the card.

“Sir Charles Abingdon,” he read aloud, staring reflectively at his secretary.  “That is the osteologist?”

“Yes,” answered Innes, “but I fancy he has retired from practice.”

“Ah,” murmured Harley, “I wonder what he wants.  I suppose I had better see him, as I fancy that he and I met casually some years ago in India.  Ask him to come in, will you?”

Innes retiring, there presently entered a distinguished-looking, elderly gentleman upon whose florid face rested an expression not unlike that of embarrassment.

“Mr. Harley,” he began, “I feel somewhat ill at ease in encroaching upon your time, for I am by no means sure that my case comes within your particular province.”

“Sit down, Sir Charles,” said Harley with quiet geniality.  “Officially, my working day is ended; but if nothing comes of your visit beyond a chat it will have been very welcome.  Calcutta, was it not, where we last met?”

“It was,” replied Sir Charles, placing his hat and cane upon the table and sitting down rather wearily in a big leather armchair which Harley had pushed forward.  “If I presume upon so slight an acquaintance, I am sorry, but I must confess that only the fact of having met you socially encouraged me to make this visit.”

He raised his eyes to Harley’s face and gazed at him with that peculiarly searching look which belongs to members of his profession; but mingled with it was an expression of almost pathetic appeal, of appeal for understanding, for sympathy of some kind.

“Go on, Sir Charles,” said Harley.  He pushed forward a box of cigars.  “Will you smoke?”

“Thanks, no,” was the answer.

Sir Charles evidently was oppressed by some secret trouble, thus Harley mused silently, as, taking out a tin of tobacco from a cabinet beside him, he began in leisurely manner to load a briar.  In this he desired to convey that he treated the visit as that of a friend, and also, since business was over, that Sir Charles might without scruple speak at length and at leisure of whatever matters had brought him there.

“Very well, then,” began the surgeon; “I am painfully conscious that the facts which I am in a position to lay before you are very scanty and unsatisfactory.”

Paul Harley nodded encouragingly.

“If this were not so,” he explained, “you would have no occasion to apply to me, Sir Charles.  It is my business to look for facts.  Naturally, I do not expect my clients to supply them.”

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.”

“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.