TABLE OF CONTENTS

CHAPTER I

MY LEARNED BROTHER

“CONFLAGRATAM AN° 1677. FABRICATAM AN° 1698. Richardo Powell Armiger Thesaurar.” The words, set in four panels, which formed a frieze beneath the pediment of a fine brick portico, summarised the history of one of the tall houses at the upper end of King’s Bench Walk and as I, somewhat absently, read over the inscription, my attention was divided between admiration of the exquisitely finished carved brickwork and the quiet dignity of the building, and an effort to reconstitute the dead and gone Richard Powell, and the stirring times in which he played his part.

I was about to turn away when the empty frame of the portico became occupied by a figure, and one so appropriate, in its wig and obsolete habiliments, to the old-world surroundings that it seemed to complete the picture, and I lingered idly to look at it. The barrister had halted in the doorway to turn over a sheaf of papers that he held in his hand, and, as he replaced the red tape which bound them together, he looked up and our eyes met. For a moment we regarded one another with the incurious gaze that casual strangers bestow on one another; then there was a flash of mutual recognition; the impassive and rather severe face of the lawyer softened into a genial smile, and the figure, detaching itself from its frame, came down the steps with a hand extended in cordial greeting.

“My dear Jervis,” he exclaimed, as we clasped hands warmly, “this is a great and delightful surprise. How often have I thought of my old comrade and wondered if I should ever see him again, and lo! here he is, thrown up on the sounding beach of the Inner Temple, like the proverbial bread cast upon the waters.”

“Your surprise, Thorndyke, is nothing to mine,” I replied, “for your bread has at least returned as bread; whereas I am in the position of a man who, having cast his bread upon the waters, sees it return in the form of a buttered muffin or a Bath bun. I left a respectable medical practitioner and I find him transformed into a bewigged and begowned limb of the law.”

Thorndyke laughed at the comparison.

“Liken not your old friend unto a Bath bun,” said he. “Say, rather, that you left him a chrysalis and come back to find him a butterfly. But the change is not so great as you think. Hippocrates is only hiding under the gown of Solon, as you will understand when I explain my metamorphosis; and that I will do this very evening, if you have no engagement.”

“I am one of the unemployed at present,” I said, “and quite at your service.”

“Then come round to my chambers at seven,” said Thorndyke, “and we will have a chop and a pint of claret together and exchange autobiographies. I am due in court in a few minutes.”

“Do you reside within that noble old portico?” I asked.

“No,” replied Thorndyke. “I often wish I did. It would add several inches to one’s stature to feel that the mouth of one’s burrow was graced with a Latin inscription for admiring strangers to ponder over. No; my chambers are some doors further down—number 6A"—and he turned to point out the house as we crossed towards Crown Office Row.

At the top of Middle Temple Lane we parted, Thorndyke taking his way with fluttering gown towards the Law Courts, while I directed my steps westward towards Adam Street, the chosen haunt of the medical agent.

The soft-voiced bell of the Temple clock was telling out the hour of seven in muffled accents (as though it apologised for breaking the studious silence) as I emerged from the archway of Mitre Court and turned into King’s Bench Walk.

The paved footway was empty save for a single figure, pacing slowly before the doorway of number 6A, in which, though the wig had now given place to a felt hat and the gown to a jacket, I had no difficulty in recognising my friend.

“Punctual to the moment, as of old,” said he, meeting me half-way. “What a blessed virtue is punctuality, even in small things. I have just been taking the air in Fountain Court, and will now introduce you to my chambers. Here is my humble retreat.”

We passed in through the common entrance and ascended the stone stairs to the first floor, where we were confronted by a massive door, above which my friend’s name was written in white letters.

“Rather a forbidding exterior,” remarked Thorndyke, as he inserted the latchkey, “but it is homely enough inside.”

The heavy door swung outwards and disclosed a baize-covered inner door, which Thorndyke pushed open and held for me to pass in.

“You will find my chambers an odd mixture,” said Thorndyke, “for they combine the attractions of an office, a museum, a laboratory and a workshop.”

“And a restaurant,” added a small, elderly man, who was decanting a bottle of claret by means of a glass syphon: “you forgot that, sir.”

“Yes, I forgot that, Polton,” said Thorndyke, “but I see you have not.” He glanced towards a small table that had been placed near the fire and set out with the requisites for our meal.

“Tell me,” said Thorndyke, as we made the initial onslaught on the products of Polton’s culinary experiments, “what has been happening to you since you left the hospital six years ago?”

“My story is soon told,” I answered, somewhat bitterly. “It is not an uncommon one. My funds ran out, as you know, rather unexpectedly. When I had paid my examination and registration fees the coffer was absolutely empty, and though, no doubt, a medical diploma contains—to use Johnson’s phrase—the potentiality of wealth beyond the dreams of avarice, there is a vast difference in practice between the potential and the actual. I have, in fact, been earning a subsistence, sometimes as an assistant, sometimes as a locum tenens. Just now I’ve got no work to do, and so have entered my name on Turcival’s list of eligibles.”

Thorndyke pursed up his lips and frowned.

“It’s a wicked shame, Jervis,” said he presently, “that a man of your abilities and scientific acquirements should be frittering away his time on odd jobs like some half-qualified wastrel.”

“It is,” I agreed. “My merits are grossly undervalued by a stiff-necked and obtuse generation. But what would you have, my learned brother? If poverty steps behind you and claps the occulting bushel over your thirty thousand candle-power luminary, your brilliancy is apt to be obscured.”

“Yes, I suppose that is so,” grunted Thorndyke, and he remained for a time in deep thought.

“And now,” said I, “let us have your promised explanation. I am positively frizzling with curiosity to know what chain of circumstances has converted John Evelyn Thorndyke from a medical practitioner into a luminary of the law.”

Thorndyke smiled indulgently.

“The fact is,” said he, “that no such transformation has occurred. John Evelyn Thorndyke is still a medical practitioner.”

“What, in a wig and gown!” I exclaimed.

“Yes, a mere sheep in wolf’s clothing,” he replied. “I will tell you how it has come about. After you left the hospital, six years ago, I stayed on, taking up any small appointments that were going—assistant demonstrator—or curatorships and such like—hung about the chemical and physical laboratories, the museum and post mortem room, and meanwhile took my M.D. and D.Sc. Then I got called to the bar in the hope of getting a coronership, but soon after this, old Stedman retired unexpectedly—you remember Stedman, the lecturer on medical jurisprudence—and I put in for the vacant post. Rather to my surprise, I was appointed lecturer, whereupon I dismissed the coronership from my mind, took my present chambers and sat down to wait for anything that might come.”

“And what has come?” I asked.

“Why, a very curious assortment of miscellaneous practice,” he replied. “At first I only got an occasional analysis in a doubtful poisoning case, but, by degrees, my sphere of influence has extended until it now includes all cases in which a special knowledge of medicine or physical science can be brought to bear upon law.”

“But you plead in court, I observe,” said I.

“Very seldom,” he replied. “More usually I appear in the character of that bête noir of judges and counsel—the scientific witness. But in most instances I do not appear at all; I merely direct investigations, arrange and analyse the results, and prime the counsel with facts and suggestions for cross-examination.”

“A good deal more interesting than acting as understudy for an absent g.p.,” said I, a little enviously. “But you deserve to succeed, for you were always a deuce of a worker, to say nothing of your capabilities.”

“Yes, I worked hard,” replied Thorndyke, “and I work hard still; but I have my hours of labour and my hours of leisure, unlike you poor devils of general practitioners, who are liable to be dragged away from the dinner table or roused out of your first sleep by—confound it all! who can that be?”

For at this moment, as a sort of commentary on his self-congratulation, there came a smart rapping at the outer door.

“Must see who it is, I suppose,” he continued, “though one expects people to accept the hint of a closed oak.”

He strode across the room and flung open the door with an air of by no means gracious inquiry.

“It’s rather late for a business call,” said an apologetic voice outside, “but my client was anxious to see you without delay.”

“Come in, Mr. Lawley,” said Thorndyke, rather stiffly, and, as he held the door open, the two visitors entered. They were both men—one middle-aged, rather foxy in appearance and of a typically legal aspect, and the other a fine, handsome young fellow of very prepossessing exterior, though at present rather pale and wild-looking, and evidently in a state of profound agitation.

“I am afraid,” said the latter, with a glance at me and the dinner table, “that our visit—for which I am alone responsible—is a most unseasonable one. If we are really inconveniencing you, Dr. Thorndyke, pray tell us, and my business must wait.”

Thorndyke had cast a keen and curious glance at the young man, and he now replied in a much more genial tone—

“I take it that your business is of a kind that will not wait, and as to inconveniencing us, why, my friend and I are both doctors, and, as you are aware, no doctor expects to call any part of the twenty-four hours his own unreservedly.”

I had risen on the entrance of the two strangers, and now proposed to take a walk on the Embankment and return later, but the young man interrupted me.

“Pray don’t go away on my account,” he said. “The facts that I am about to lay before Dr. Thorndyke will be known to all the world by this time to-morrow, so there is no occasion for any show of secrecy.”

“In that case,” said Thorndyke, “let us draw our chairs up to the fire and fall to business forthwith. We had just finished our dinner and were waiting for the coffee, which I hear my man bringing down at this moment.”

We accordingly drew up our chairs, and when Polton had set the coffee on the table and retired, the lawyer plunged into the matter without preamble.

CHAPTER II

THE SUSPECT

“I HAD BETTER,” SAID HE, “give you a general outline of the case as it presents itself to the legal mind, and then my client, Mr. Reuben Hornby, can fill in the details if necessary, and answer any questions that you may wish to put to him.

“Mr. Reuben occupies a position of trust in the business of his uncle, John Hornby, who is a gold and silver refiner and dealer in precious metals generally. There is a certain amount of outside assay work carried on in the establishment, but the main business consists in the testing and refining of samples of gold sent from certain mines in South Africa.

“About five years ago Mr. Reuben and his cousin Walter—another nephew of John Hornby—left school, and both were articled to their uncle, with the view to their ultimately becoming partners in the house; and they have remained with him ever since, occupying, as I have said, positions of considerable responsibility.

“And now for a few words as to how business is conducted in Mr. Hornby’s establishment. The samples of gold are handed over at the docks to some accredited representative of the firm—generally either Mr. Reuben or Mr. Walter—who has been despatched to meet the ship, and conveyed either to the bank or to the works according to circumstances. Of course every effort is made to have as little gold as possible on the premises, and the bars are always removed to the bank at the earliest opportunity; but it happens unavoidably that samples of considerable value have often to remain on the premises all night, and so the works are furnished with a large and powerful safe or strong room for their reception. This safe is situated in the private office under the eye of the principal, and, as an additional precaution, the caretaker, who acts as night-watchman, occupies a room directly over the office, and patrols the building periodically through the night.

“Now a very strange thing has occurred with regard to this safe. It happens that one of Mr. Hornby’s customers in South Africa is interested in a diamond mine, and, although transactions in precious stones form no part of the business of the house, he has, from time to time, sent parcels of rough diamonds addressed to Mr. Hornby, to be either deposited in the bank or handed on to the diamond brokers.

“A fortnight ago Mr. Hornby was advised that a parcel of stones had been despatched by the Elmina Castle, and it appeared that the parcel was an unusually large one and contained stones of exceptional size and value. Under these circumstances Mr. Reuben was sent down to the docks at an early hour in the hope the ship might arrive in time for the stones to be lodged in the bank at once. Unfortunately, however, this was not the case, and the diamonds had to be taken to the works and locked up in the safe.”

“Who placed them in the safe?” asked Thorndyke.

“Mr. Hornby himself, to whom Mr. Reuben delivered up the package on his return from the docks.”

“Yes,” said Thorndyke, “and what happened next?”

“Well, on the following morning, when the safe was opened, the diamonds had disappeared.”

“Had the place been broken into?” asked Thorndyke.

“No. The place was all locked up as usual, and the caretaker, who had made his accustomed rounds, had heard nothing, and the safe was, outwardly, quite undisturbed. It had evidently been opened with keys and locked again after the stones were removed.”

“And in whose custody were the keys of the safe?” inquired Thorndyke.

“Mr. Hornby usually kept the keys himself, but, on occasions, when he was absent from the office, he handed them over to one of his nephews—whichever happened to be in charge at the time. But on this occasion the keys did not go out of his custody from the time when he locked up the safe, after depositing the diamonds in it, to the time when it was opened by him on the following morning.”

“And was there anything that tended to throw suspicion upon anyone?” asked Thorndyke.

“Why, yes,” said Mr. Lawley, with an uncomfortable glance at his client, “unfortunately there was. It seemed that the person who abstracted the diamonds must have cut or scratched his thumb or finger in some way, for there were two drops of blood on the bottom of the safe and one or two bloody smears on a piece of paper, and, in addition, a remarkably clear imprint of a thumb.”

“Also in blood?” asked Thorndyke.

“Yes. The thumb had apparently been put down on one of the drops and then, while still wet with blood, had been pressed on the paper in taking hold of it or otherwise.”

“Well, and what next?”

“Well,” said the lawyer, fidgeting in his chair, “to make a long story short, the thumb-print has been identified as that of Mr. Reuben Hornby.”

“Ha!” exclaimed Thorndyke. “The plot thickens with a vengeance. I had better jot down a few notes before you proceed any further.”

He took from a drawer a small paper-covered notebook, on the cover of which he wrote “Reuben Hornby,” and then, laying the book open on a blotting-pad, which he rested on his knee, he made a few brief notes.

“Now,” he said, when he had finished, “with reference to this thumb-print. There is no doubt, I suppose, as to the identification?”

“None whatever,” replied Mr. Lawley. “The Scotland Yard people, of course, took possession of the paper, which was handed to the director of the finger-print department for examination and comparison with those in their collection. The report of the experts is that the thumb-print does not agree with any of the thumb-prints of criminals in their possession; that it is a very peculiar one, inasmuch as the ridge-pattern on the bulb of the thumb—which is a remarkably distinct and characteristic one—is crossed by the scar of a deep cut, rendering identification easy and infallible; that it agrees in every respect with the thumb-print of Mr. Reuben Hornby, and is, in fact, his thumb-print beyond any possible doubt.”

“Is there any possibility,” asked Thorndyke, “that the paper bearing the thumb-print could have been introduced by any person?”

“No,” answered the lawyer. “It is quite impossible. The paper on which the mark was found was a leaf from Mr. Hornby’s memorandum block. He had pencilled on it some particulars relating to the diamonds, and laid it on the parcel before he closed up the safe.”

“Was anyone present when Mr. Hornby opened the safe in the morning?” asked Thorndyke.

“No, he was alone,” answered the lawyer. “He saw at a glance that the diamonds were missing, and then he observed the paper with the thumb-mark on it, on which he closed and locked the safe and sent for the police.”

“Is it not rather odd that the thief did not notice the thumb-mark, since it was so distinct and conspicuous?”

“No, I think not,” answered Mr. Lawley. “The paper was lying face downwards on the bottom of the safe, and it was only when he picked it up and turned it over that Mr. Hornby discovered the thumb-print. Apparently the thief had taken hold of the parcel, with the paper on it, and the paper had afterwards dropped off and fallen with the marked surface downwards—probably when the parcel was transferred to the other hand.”

“You mentioned,” said Thorndyke, “that the experts at Scotland Yard have identified this thumb-mark as that of Mr. Reuben Hornby. May I ask how they came to have the opportunity of making the comparison?”

“Ah!” said Mr. Lawley. “Thereby hangs a very curious tale of coincidences. The police, of course, when they found that there was so simple a means of identification as a thumb-mark, wished to take thumb-prints of all the employees in the works; but this Mr. Hornby refused to sanction—rather quixotically, as it seems to me—saying that he would not allow his nephews to be subjected to such an indignity. Now it was, naturally, these nephews in whom the police were chiefly interested, seeing that they alone had had the handling of the keys, and considerable pressure was brought to bear upon Mr. Hornby to have the thumb-prints taken.

“However, he was obdurate, scouting the idea of any suspicion attaching to either of the gentlemen in whom he had reposed such complete confidence and whom he had known all their lives, and so the matter would probably have remained a mystery but for a very odd circumstance.

“You may have seen on the bookstalls and in shop windows an appliance called a ‘Thumbograph,’ or some such name, consisting of a small book of blank paper for collecting the thumb-prints of one’s friends, together with an inking pad.”

“I have seen those devices of the Evil One,” said Thorndyke, “in fact, I have one, which I bought at Charing Cross Station.”

“Well, it seems that some months ago Mrs. Hornby, the wife of John Hornby, purchased one of these toys—”

“As a matter of fact,” interrupted Reuben, “it was my cousin Walter who bought the thing and gave it to her.”

“Well, that is not material,” said Mr. Lawley (though I observed that Thorndyke made a note of the fact in his book); “at any rate, Mrs. Hornby became possessed of one of these appliances and proceeded to fill it with the thumb-prints of her friends, including her two nephews. Now it happened that the detective in charge of this case called yesterday at Mr. Hornby’s house when the latter was absent from home, and took the opportunity of urging her to induce her husband to consent to have the thumb-prints of her nephews taken for the inspection of the experts at Scotland Yard. He pointed out that the procedure was really necessary, not only in the interests of justice but in the interests of the young men themselves, who were regarded with considerable suspicion by the police, which suspicion would be completely removed if it could be shown by actual comparison that the thumb-print could not have been made by either of them. Moreover, it seemed that both the young men had expressed their willingness to have the test applied, but had been forbidden by their uncle. Then Mrs. Hornby had a brilliant idea. She suddenly remembered the ‘Thumbograph,’ and thinking to set the question at rest once for all, fetched the little book and showed it to the detective. It contained the prints of both thumbs of Mr. Reuben (among others), and, as the detective had with him a photograph of the incriminating mark, the comparison was made then and there; and you may imagine Mrs. Hornby’s horror and amazement when it was made clear that the print of her nephew Reuben’s left thumb corresponded in every particular with the thumb-print that was found in the safe.

“At this juncture Mr. Hornby arrived on the scene and was, of course, overwhelmed with consternation at the turn events had taken. He would have liked to let the matter drop and make good the loss of the diamonds out of his own funds, but, as that would have amounted practically to compounding a felony, he had no choice but to prosecute. As a result, a warrant was issued for the arrest of Mr. Reuben, and was executed this morning, and my client was taken forthwith to Bow Street and charged with the robbery.”

“Was any evidence taken?” asked Thorndyke.

“No. Only evidence of arrest. The prisoner is remanded for a week, bail having been accepted in two sureties of five hundred pounds each.”

Thorndyke was silent for a space after the conclusion of the narrative. Like me, he was evidently not agreeably impressed by the lawyer’s manner, which seemed to take his client’s guilt for granted, a position indeed not entirely without excuse having regard to the circumstances of the case.

“What have you advised your client to do?” Thorndyke asked presently.

“I have recommended him to plead guilty and throw himself on the clemency of the court as a first offender. You must see for yourself that there is no defence possible.”

The young man flushed crimson, but made no remark.

“But let us be clear how we stand,” said Thorndyke. “Are we defending an innocent man or are we endeavouring to obtain a light sentence for a man who admits that he is guilty?”

Mr. Lawley shrugged his shoulders.

“That question can be best answered by our client himself,” said he.

Thorndyke directed an inquiring glance at Reuben Hornby, remarking—

“You are not called upon to incriminate yourself in any way, Mr. Hornby, but I must know what position you intend to adopt.”

Here I again proposed to withdraw, but Reuben interrupted me.

“There is no need for you to go away, Dr. Jervis,” he said. “My position is that I did not commit this robbery and that I know nothing whatever about it or about the thumb-print that was found in the safe. I do not, of course, expect you to believe me in the face of the overwhelming evidence against me, but I do, nevertheless, declare in the most solemn manner before God, that I am absolutely innocent of this crime and have no knowledge of it whatever.”

“Then I take it that you did not plead ‘guilty’?” said Thorndyke.

“Certainly not; and I never will,” replied Reuben hotly.

“You would not be the first innocent man, by very many, who has entered that plea,” remarked Mr. Lawley. “It is often the best policy, when the defence is hopelessly weak.”

“It is a policy that will not be adopted by me,” rejoined Reuben. “I may be, and probably shall be, convicted and sentenced, but I shall continue to maintain my innocence, whatever happens. Do you think,” he added, turning to Thorndyke, “that you can undertake my defence on that assumption?”

“It is the only assumption on which I should agree to undertake the case,” replied Thorndyke.

“And—if I may ask the question—” pursued Reuben anxiously, “do you find it possible to conceive that I may really be innocent?”

“Certainly I do,” Thorndyke replied, on which I observed Mr. Lawley’s eyebrows rise perceptibly. “I am a man of facts, not an advocate, and if I found it impossible to entertain the hypothesis of your innocence, I should not be willing to expend time and energy in searching for evidence to prove it. Nevertheless,” he continued, seeing the light of hope break out on the face of the unfortunate young man, “I must impress upon you that the case presents enormous difficulties and that we must be prepared to find them insuperable in spite of all our efforts.”

“I expect nothing but a conviction,” replied Reuben in a calm and resolute voice, “and can face it like a man if only you do not take my guilt for granted, but give me a chance, no matter how small, of making a defence.”

“Everything shall be done that I am capable of doing,” said Thorndyke; “that I can promise you. The long odds against us are themselves a spur to endeavour, as far as I am concerned. And now, let me ask you, have you any cuts or scratches on your fingers?”

Reuben Hornby held out both his hands for my colleague’s inspection, and I noticed that they were powerful and shapely, like the hands of a skilled craftsman, though faultlessly kept. Thorndyke set on the table a large condenser such as is used for microscopic work, and taking his client’s hand, brought the bright spot of light to bear on each finger in succession, examining their tips and the parts around the nails with the aid of a pocket lens.

“A fine, capable hand, this,” said he, regarding the member approvingly, as he finished his examination, “but I don’t perceive any trace of a scar on either the right or left. Will you go over them, Jervis? The robbery took place a fortnight ago, so there has been time for a small cut or scratch to heal and disappear entirely. Still, the matter is worth noting.”

He handed me the lens and I scrutinised every part of each hand without being able to detect the faintest trace of any recent wound.

“There is one other matter that must be attended to before you go,” said Thorndyke, pressing the electric bell-push by his chair. “I will take one or two prints of the left thumb for my own information.”

In response to the summons, Polton made his appearance from some lair unknown to me, but presumably the laboratory, and, having received his instructions, retired, and presently returned carrying a box, which he laid on the table. From this receptacle Thorndyke drew forth a bright copper plate mounted on a slab of hard wood, a small printer’s roller, a tube of finger-print ink, and a number of cards with very white and rather glazed surfaces.

“Now, Mr. Hornby,” said he, “your hands, I see, are beyond criticism as to cleanliness, but we will, nevertheless, give the thumb a final polish.”

Accordingly he proceeded to brush the bulb of the thumb with a well-soaked badger-hair nail-brush, and, having rinsed it in water, dried it with a silk handkerchief, and gave it a final rub on a piece of chamois leather. The thumb having been thus prepared, he squeezed out a drop of the thick ink on to the copper plate and spread it out with the roller, testing the condition of the film from time to time by touching the plate with the tip of his finger and taking an impression on one of the cards.

When the ink had been rolled out to the requisite thinness, he took Reuben’s hand and pressed the thumb lightly but firmly on to the inked plate; then, transferring the thumb to one of the cards, which he directed me to hold steady on the table, he repeated the pressure, when there was left on the card a beautifully sharp and clear impression of the bulb of the thumb, the tiny papillary ridges being shown with microscopic distinctness, and even the mouths of the sweat glands, which appeared as rows of little white dots on the black lines of the ridges. This manoeuvre was repeated a dozen times on two of the cards, each of which thus received six impressions. Thorndyke then took one or two rolled prints, i.e. prints produced by rolling the thumb first on the inked slab and then on the card, by which means a much larger portion of the surface of the thumb was displayed in a single print.

“And now,” said Thorndyke, “that we may be furnished with all the necessary means of comparison, we will take an impression in blood.”

The thumb was accordingly cleansed and dried afresh, when Thorndyke, having pricked his own thumb with a needle, squeezed out a good-sized drop of blood on to a card.

“There,” said he, with a smile, as he spread the drop out with the needle into a little shallow pool, “it is not every lawyer who is willing to shed his blood in the interests of his client.”

He proceeded to make a dozen prints as before on two cards, writing a number with his pencil opposite each print as he made it.

“We are now,” said he, as he finally cleansed his client’s thumb, “furnished with the material for a preliminary investigation, and if you will now give me your address, Mr. Hornby, we may consider our business concluded for the present. I must apologise to you, Mr. Lawley, for having detained you so long with these experiments.”

The lawyer had, in fact, been viewing the proceedings with hardly concealed impatience, and he now rose with evident relief that they were at an end.

“I have been highly interested,” he said mendaciously, “though I confess I do not quite fathom your intentions. And, by the way, I should like to have a few words with you on another matter, if Mr. Reuben would not mind waiting for me in the square just a few minutes.”

“Not at all,” said Reuben, who was, I perceived, in no way deceived by the lawyer’s pretence. “Don’t hurry on my account; my time is my own—at present.” He held out his hand to Thorndyke, who grasped it cordially.

“Good-bye, Mr. Hornby,” said the latter. “Do not be unreasonably sanguine, but at the same time, do not lose heart. Keep your wits about you and let me know at once if anything occurs to you that may have a bearing on the case.”

The young man then took his leave, and, as the door closed after him, Mr. Lawley turned towards Thorndyke.

“I thought I had better have a word with you alone,” he said, “just to hear what line you propose to take up, for I confess that your attitude has puzzled me completely.”

“What line would you propose?” asked Thorndyke.

“Well,” said the lawyer, with a shrug of his shoulders, “the position seems to be this: our young friend has stolen a parcel of diamonds and has been found out; at least, that is how the matter presents itself to me.”

“That is not how it presents itself to me,” said Thorndyke drily. “He may have taken the diamonds or he may not. I have no means of judging until I have sifted the evidence and acquired a few more facts. This I hope to do in the course of the next day or two, and I suggest that we postpone the consideration of our plan of campaign until I have seen what line of defence it is possible to adopt.”

“As you will,” replied the lawyer, taking up his hat, “but I am afraid you are encouraging the young rogue to entertain hopes that will only make his fall the harder—to say nothing of our own position. We don’t want to make ourselves ridiculous in court, you know.”

“I don’t, certainly,” agreed Thorndyke. “However, I will look into the matter and communicate with you in the course of a day or two.”

He stood holding the door open as the lawyer descended the stairs, and when the footsteps at length died away, he closed it sharply and turned to me with an air of annoyance.

“The ‘young rogue,’” he remarked, “does not appear to me to have been very happy in his choice of a solicitor. By the way, Jervis, I understand you are out of employment just now?”

“That is so,” I answered.

“Would you care to help me—as a matter of business, of course—to work up this case? I have a lot of other work on hand and your assistance would be of great value to me.”

I said, with great truth, that I should be delighted.

“Then,” said Thorndyke, “come round to breakfast to-morrow and we will settle the terms, and you can commence your duties at once. And now let us light our pipes and finish our yarns as though agitated clients and thick-headed solicitors had no existence.”

CHAPTER III

A LADY IN THE CASE

WHEN I ARRIVED AT THORNDYKE’S chambers on the following morning, I found my friend already hard at work. Breakfast was laid at one end of the table, while at the other stood a microscope of the pattern used for examining plate-cultures of micro-organisms, on the wide stage of which was one of the cards bearing six thumb-prints in blood. A condenser threw a bright spot of light on the card, which Thorndyke had been examining when I knocked, as I gathered from the position of the chair, which he now pushed back against the wall.

“I see you have commenced work on our problem,” I remarked as, in response to a double ring of the electric bell, Polton entered with the materials for our repast.

“Yes,” answered Thorndyke. “I have opened the campaign, supported, as usual, by my trusty chief-of-staff; eh! Polton?”

The little man, whose intellectual, refined countenance and dignified bearing seemed oddly out of character with the tea-tray that he carried, smiled proudly, and, with a glance of affectionate admiration at my friend, replied—

“Yes, sir. We haven’t been letting the grass grow under our feet. There’s a beautiful negative washing upstairs and a bromide enlargement too, which will be mounted and dried by the time you have finished your breakfast.”

“A wonderful man that, Jervis,” my friend observed as his assistant retired. “Looks like a rural dean or a chancery judge, and was obviously intended by Nature to be a professor of physics. As an actual fact he was first a watchmaker, then a maker of optical instruments, and now he is mechanical factotum to a medical jurist. He is my right-hand, is Polton; takes an idea before you have time to utter it—but you will make his more intimate acquaintance by-and-by.”

“Where did you pick him up?” I asked.

“He was an in-patient at the hospital when I first met him, miserably ill and broken, a victim of poverty and undeserved misfortune. I gave him one or two little jobs, and when I found what class of man he was I took him permanently into my service. He is perfectly devoted to me, and his gratitude is as boundless as it is uncalled for.”

“What are the photographs he was referring to?” I asked.

“He is making an enlarged facsimile of one of the thumb-prints on bromide paper and a negative of the same size in case we want the print repeated.”

“You evidently have some expectation of being able to help poor Hornby,” said I, “though I cannot imagine how you propose to go to work. To me his case seems as hopeless a one as it is possible to conceive. One doesn’t like to condemn him, but yet his innocence seems almost unthinkable.”

“It does certainly look like a hopeless case,” Thorndyke agreed, “and I see no way out of it at present. But I make it a rule, in all cases, to proceed on the strictly classical lines of inductive inquiry—collect facts, make hypotheses, test them and seek for verification. And I always endeavour to keep a perfectly open mind.

“Now, in the present case, assuming, as we must, that the robbery has actually taken place, there are four conceivable hypotheses: (1) that the robbery was committed by Reuben Hornby; (2) that it was committed by Walter Hornby; (3) that it was committed by John Hornby, or (4) that it was committed by some other person or persons.

“The last hypothesis I propose to disregard for the present and confine myself to the examination of the other three.”

“You don’t think it possible that Mr. Hornby could have stolen the diamonds out of his own safe?” I exclaimed.

“I incline at present to no one theory of the matter,” replied Thorndyke. “I merely state the hypotheses. John Hornby had access to the diamonds, therefore it is possible that he stole them.”

“But surely he was responsible to the owners.”

“Not in the absence of gross negligence, which the owners would have difficulty in proving. You see, he was what is called a gratuitous bailee, and in such a case no responsibility for loss lies with the bailee unless there has been gross negligence.”

“But the thumb-mark, my dear fellow!” I exclaimed. “How can you possibly get over that?”

“I don’t know that I can,” answered Thorndyke calmly; “but I see you are taking the same view as the police, who persist in regarding a finger-print as a kind of magical touchstone, a final proof, beyond which inquiry need not go. Now, this is an entire mistake. A finger-print is merely a fact—a very important and significant one, I admit—but still a fact, which, like any other fact, requires to be weighed and measured with reference to its evidential value.”

“And what do you propose to do first?”

“I shall first satisfy myself that the suspected thumb-print is identical in character with that of Reuben Hornby—of which, however, I have very little doubt, for the finger-print experts may fairly be trusted in their own speciality.”

“And then?”

“I shall collect fresh facts, in which I look to you for assistance, and, if we have finished breakfast, I may as well induct you into your new duties.”

He rose and rang the bell, and then, fetching from the office four small, paper-covered notebooks, laid them before me on the table.

“One of these books,” said he, “we will devote to data concerning Reuben Hornby. You will find out anything you can—anything, mind, no matter how trivial or apparently irrelevant—in any way connected with him and enter it in this book.” He wrote on the cover “Reuben Hornby” and passed the book to me. “In this second book you will, in like manner, enter anything that you can learn about Walter Hornby, and, in the third book, data concerning John Hornby. As to the fourth book, you will keep that for stray facts connected with the case but not coming under either of the other headings. And now let us look at the product of Polton’s industry.”

He took from his assistant’s hand a photograph ten inches long by eight broad, done on glazed bromide paper and mounted flatly on stiff card. It showed a greatly magnified facsimile of one of the thumb-prints, in which all the minute details, such as the orifices of the sweat glands and trifling irregularities in the ridges, which, in the original, could be seen only with the aid of a lens, were plainly visible to the naked eye. Moreover, the entire print was covered by a network of fine black lines, by which it was divided into a multitude of small squares, each square being distinguished by a number.