THE PUZZLE LOCK

by R. Austin Freeman

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TABLE OF CONTENTS

I. — THE PUZZLE LOCK

II. — THE GREEN CHECK JACKET

III. — THE SEAL OF NEBUCHADNEZZAR

IV. — PHYLLIS ANNESLEY'S PERIL

V. — A SOWER OF PESTILENCE

VI. — REX V. BURNABY

VII. — A MYSTERY OF THE SAND-HILLS

VIII. — THE APPARITION OF BURLING COURT

IX. — THE MYSTERIOUS VISITOR

I. — THE PUZZLE LOCK

I DO not remember what was the occasion of my dining with Thorndyke at Giamborini's on the particular evening that is now in my mind. Doubtless, some piece of work completed had seemed to justify the modest festival. At any rate, there we were, seated at a somewhat retired table, selected by Thorndyke, with our backs to the large window through which the late June sunlight streamed. We had made our preliminary arrangements, including a bottle of Barsac, and were inspecting dubiously a collection of semi-edible hors d'oeuvres, when a man entered and took possession of a table just in front of ours, which had apparently been reserved for him, since he walked directly to it and drew away the single chair that had been set aslant against it.

I watched with amused interest his methodical procedure, for he was clearly a man who took his dinner seriously. A regular customer, too, I judged by the waiter's manner and the reserved table with its single chair. But the man himself interested me. He was out of the common and there was a suggestion of character, with perhaps a spice of oddity, in his appearance. He appeared to be about sixty years of age, small and spare, with a much-wrinkled, mobile and rather whimsical face, surmounted by a crop of white, upstanding hair. From his waistcoat pocket protruded the ends of a fountain-pen, a pencil and a miniature electric torch such as surgeons use; a silver-mounted Coddington lens hung from his watch-guard and the middle finger of his left hand bore the largest seal ring that I have ever seen.

"Well," said Thorndyke, who had been following my glance, "what do you make of him?"

"I don't quite know," I replied. "The Coddington suggests a naturalist or a scientist of some kind, but that blatant ring doesn't. Perhaps he is an antiquary or a numismatist or even a philatelist. He deals with small objects of some kind."

At this moment a man who had just entered strode up to our friend's table and held out his hand, which the other shook, with no great enthusiasm, as I thought. Then the newcomer fetched a chair, and setting it by the table, seated himself and picked up the menu card, while the other observed him with a shade of disapproval. I judged that he would rather have dined alone, and that the personality of the new arrival—a flashy, bustling, obtrusive type of man—did not commend him.

From this couple my eye was attracted to a tall man who had halted near the door and stood looking about the room as if seeking someone. Suddenly he spied an empty, single table, and, bearing down on it, seated himself and began anxiously to study the menu under the supervision of a waiter. I glanced at him with slight disfavour. One makes allowances for the exuberance of youth, but when a middle-aged man presents the combination of heavily-greased heir parted in the middle, a waxed moustache of a suspiciously intense black, a pointed imperial and a single eye-glass, evidently ornamental in function, one views him with less tolerance. However, his get-up was not my concern, whereas my dinner was, and I had given this my undivided attention for some minutes when I heard Thorndyke emit a soft chuckle.

"Not bad," he remarked, setting down his glass.

"Not at all," I agreed, "for a restaurant wine."

"I was not alluding to the wine," said he "but to our friend Badger."

"The inspector!" I exclaimed. "He isn't here, is he? I don't see him."

"I am glad to hear you say that, Jervis," said he. "It is a better effort than I thought. Still, he might manage his properties a little better. That is the second time his eye-glass has been in the soup."

Following, the direction of his glance, I observed the man with the waxed moustache furtively wiping his eye-glass; and the temporary absence of the monocular grimace enabled me to note a resemblance to the familiar features of the detective officer.

"If you say that is Badger, I suppose it is," said I. "He is certainly a little like our friend. But I shouldn't have recognised him."

"I don't know that I should," said Thorndyke, "but for the little unconscious tricks of movement. You know the habit he has of stroking the back of his head, and of opening his mouth and scratching the side of his chin. I saw him do it just now. He had forgotten his imperial until he touched it, and then the sudden arrest of movement was very striking. It doesn't do to forget a false beard."

"I wonder what his game is," said I. "The disguise suggests that he is on the look-out for somebody who might know him; but apparently that somebody has not turned up yet. At any rate, he doesn't seem to be watching anybody in particular."

"No," said Thorndyke. "But there is somebody whom he seems rather to avoid watching. Those two men at the table in front of ours are in his direct line of vision, but he hasn't looked at them once since he sat down, though I noticed that he gave them one quick glance before he selected his table. I wonder if he has observed us. Probably not, as we have the strong light of the window behind us and his attention is otherwise occupied."

I looked at the two men and from them to the detective, and I judged that my friend was right. On the inspector's table was a good-sized fern in an ornamental pot, and this he had moved so that it was directly between him and the two strangers, to whom he must have been practically invisible; and now I could see that he did, in fact, steal an occasional glance at them over the edge of the menu card. Moreover, as their meal drew to an end, he hastily finished his own and beckoned to the waiter to bring the bill.

"We may as well wait and see them off," said Thorndyke, who had already settled our account. "Badger always interests me. He is so ingenious and he has such shockingly bad luck."

We had not long to wait. The two men rose from the table and walked slowly to the door, where they paused to light their cigars before going out. Then Badger rose, with his back towards them and his eyes on the mirror opposite; and as they went out, he snatched up his hat and stick and followed. Thorndyke looked at me inquiringly.

"Do we indulge in the pleasures of the chase?" he asked, and as I replied in the affirmative, we, too, made our way out and started in the wake of the inspector.

As we followed Badger at a discreet distance, we caught an occasional glimpse of the quarry ahead, whose proceedings evidently caused the inspector some embarrassment, for they had a way of stopping suddenly to elaborate some point that they were discussing, whereby it became necessary for the detective to drop farther in the rear than was quite safe, in view of the rather crowded state of the pavement. On one of these occasions, when the older man was apparently delivering himself of some excruciating joke, they both turned suddenly and looked back, the joker pointing to some object on the opposite side of the road. Several people turned to see what was being pointed at, and, of course, the inspector had to turn, too, to avoid being recognised. At this moment the two men popped into an entry, and when the inspector once more turned they were gone.

As soon as he missed them, Badger started forward almost at a run, and presently halted at the large entry of the Celestial Bank Chambers, into which he peered eagerly. Then, apparently sighting his quarry, he darted in, and we quickened our pace and followed. Half-way down the long hall we saw him standing at the door of a lift, frantically pressing the call-button.

"Poor Badger!" chuckled Thorndyke, as we walked past him unobserved. "His usual luck! He will hardly run them to earth now in this enormous building. We may as well go through to the Blenheim Street entrance."

We pursued our way along the winding corridor and were close to the entrance when I noticed two men coming down the staircase that led to the ball.

"By Jingo! Here they are!" I exclaimed. "Shall we run back and give Badger the tip?"

Thorndyke hesitated. But it was too late. A taxi had just driven up and was discharging its fare. The younger man, catching the driver's eye, ran out and seized the door-handle; and when his companion had entered the cab, he gave an address to the driver, and, stepping in quickly, slammed the door. As the cab moved off, Thorndyke pulled out his notebook and pencil and jotted down the number of the vehicle. Then we turned and retraced our steps; but when we reached the lift-door, the inspector had disappeared. Presumably, like the incomparable Tom Bowling, he had gone aloft.

"We must give it up, Jervis," said Thorndyke. "I will send him anonymously the number of the cab, and that is all we can do. But I am sorry for Badger."

With this we dismissed the incident from our minds—at least, I did; assuming that I had seen the last of the two strangers. Little did I suspect how soon and under what strange and tragic circumstances I should meet with them again!

It was about a week later that we received a visit from our old friend, Superintendent Miller of the Criminal Investigation Department. The passing years had put us on a footing of mutual trust and esteem, and the capable, straightforward detective officer was always a welcome visitor.

"I've just dropped in," said Miller, cutting off the end of the inevitable cigar, "to tell you about a rather queer case that we've got in hand. I know you are always interested in queer cases."

Thorndyke smiled blandly. He had heard that kind of preamble before, and he knew, as did I, that when Miller became communicative we could safely infer that the Millerian bark was in shoal water.

"It is a case," the superintendent continued, "of a very special brand of crook. Actually there is a gang, but it is the managing director that we have particularly got our eye on."

"Is he a regular 'habitual,' then?" asked Thorndyke.

"Well," replied Miller, "as to that, I can't positively say. The fact is that we haven't actually seen the man to be sure of him."

"I see," said Thorndyke, with a grim smile. "You mean to say that you have got your eye on the place where he isn't."

"At the present moment," Miller admitted, "that is the literal fact. We have lost sight of the man we suspected, but we hope to pick him up again presently. We want him badly, and his pals too. It is probably quite a small gang, but they are mighty fly; a lot too smart to be at large. And they'll take some catching, for there is someone running the concern with a good deal more brains than crooks usually have."

"What is their lay?" I asked.

"Burglary," he replied. "Jewels and plate, but principally jewels; and the special feature of their work is that the swag disappears completely every time. None of the stuff has ever been traced. That is what drew our attention to them. After each robbery we made a round of all the fences, but there was not a sign. The stuff seemed to have vanished into smoke. Now that is very awkward. If you never see the men and you can't trace the stuff, where are you? You've got nothing to go on."

"But you seem to have got a clue of some kind." I said.

"Yes. There isn't a lot in it; but it seemed worth following up. One of our men happened to travel down to Colchester with a certain man, and when he came back two days later, he noticed this same man on the platform at Colchester and saw him get out at Liverpool Street. In the interval there had been a jewel robbery at Colchester. Then there was a robbery at Southampton, and our man went at once to Waterloo and saw all the trains in. On the second day, behold! the Colchester sportsman turns up at the barrier, so our man, who had a special taxi waiting, managed to track him home and afterwards got some particulars about him. He is a chap named Shemmonds; belongs to a firm of outside brokers. But nobody seems to know much about him and he doesn't put in much time at the office.

"Well, then, Badger took him over and shadowed him for a day or two, but just as things were looking interesting, he slipped off the hook. Badger followed him to a restaurant, and, through the glass door, saw him go up to an elderly man at a table and shake hands with him. Then he took a chair at the table himself, so Badger popped in and took a seat near them where he could keep them in view. They went out together and Badger followed them, but he lost them in the Celestial Bank Chambers. They went up in the lift just before he could get to the door and that was the last he saw of them. But we have ascertained that they left the building in a taxi and that the taxi set them down at Great Turnstile."

"It was rather smart of you to trace the cab," Thorndyke remarked.

"You've got to keep your eyes skinned in our line of business," said Miller. "But now we come to the real twister. From the time those two men went down Great Turnstile, nobody has set eyes on either of them. They seem to have vanished into thin air."

"You found out who the other man was, then?" said I.

"Yes. The restaurant manager knew him; an old chap named Luttrell. And we knew him, too, because he has a thumping burglary insurance, and when he goes out of town he notifies his company, and they make arrangements with us to have the premises watched."

"What is Luttrell?" I asked.

"Well, he is a bit of a mug, I should say, at least that's his character in the trade. Goes in for being a dealer in jewels and antiques, but he'll buy anything—furniture, pictures, plate, any blooming thing. Does it for a hobby, the regular dealers say. Likes the sport of bidding at the sales. But the knock-out men hate him; never know what he's going to do. Must have private means, for though he doesn't often drop money, he can't make much. He's no salesman. It is the buying that he seems to like. But he is a regular character, full of cranks and oddities. His rooms in Thavies Inn look like the British Museum gone mad. He has got electric alarms from all the doors up to his bedroom and the strong-room in his office is fitted with a puzzle lock instead of keys."

"That doesn't seem very safe," I remarked.

"It is," said Miller. "This one has fifteen alphabets. One of our men has calculated that it has about forty billion changes. No one is going to work that out, and there are no keys to get lost. But it is that strong-room that is worrying us, as well as the old joker himself. The Lord knows how much valuable stuff there is in it. What we are afraid of is that Shemmonds may have made away with the old chap and be lying low, waiting to swoop down on that strong-room."

"But you said that Luttrell goes away sometimes," said I.

"Yes; but then he always notifies his insurance company and he seals up his strong-room with a tape round the door-handle and a great seal on the door-post. This time he hasn't notified the company and the door isn't sealed. There's a seal on the door-post—left from last time, I expect—but only the cut ends of tape. I got the caretaker to let me see the place this morning; and, by the way, doctor, I have taken a leaf out of your book. I always carry a bit of squeezing wax in my pocket now and a little box of French chalk. Very handy they are, too. As I had 'em with me this morning, I took a squeeze of the seal. May want it presently for identification."

He brought out of his pocket a small tin box from which he carefully extracted an object wrapped in tissue paper. When the paper had been tenderly removed there was revealed a lump of moulding wax, one side of which was flattened and bore a sunk design.

"It's quite a good squeeze," said Miller, handing it to Thorndyke. "I dusted the seal with French chalk so that the wax shouldn't stick to it."

My colleague examined the "squeeze" through his lens, and passing it and the lens to me, asked: "Has this been photographed, Miller?"

"No," was the reply, "but it ought to be before it gets damaged."

"It ought, certainly," said Thorndyke, "if you value it. Shall I get Polton to do it now?"

The superintendent accepted the offer gratefully and Thorndyke accordingly took the squeeze up to the laboratory, where he left it for our assistant to deal with. When he returned, Miller remarked: "It is a baffling case, this. Now that Shemmonds has dropped out of sight, there is nothing to go on and nothing to do but wait for something else to happen; another burglary or an attempt on the strong-room."

"Is it clear that the strong-room has not been opened?" asked Thorndyke.

"No, it isn't," replied Miller. "That's part of the trouble. Luttrell has disappeared and he may be dead. If he is, Shemmonds will probably have been through his pockets. Of course there is no strong-room key. That is one of the advantages of a puzzle lock. But it is quite possible that Luttrell may have kept a note of the combination and carried it about him. It would have been risky to trust entirely to memory. And he would have had the keys of the office about him. Any one who had those could have slipped in during business hours without much difficulty. Luttrell's premises are empty, but there are people in and out all day going to the other offices. Our man can't follow them all in. I suppose you can't make any suggestion, doctor?"

"I am afraid I can't," answered Thorndyke. "The case is so very much in the air. There is nothing against Shemmonds but bare suspicion. He has disappeared only in the sense that you have lost sight of him, and the same is true of Luttrell—though there is an abnormal element in his case. Still, you could hardly get a search-warrant on the facts that are known at present."

"No," Miller agreed, "they certainly would not authorise us to break open the strong-room, and nothing short of that would be much use."

Here Polton made his appearance with the wax squeeze in a neat little box such as jewellers use.

"I've got two enlarged negatives," said he; "nice clear ones. How many prints shall I make for Mr. Miller?"

"Oh, one will do, Mr. Polton," said the superintendent. "If I want any more I'll ask you." He took up the little box, and, slipping it in his pocket, rose to depart. "I'll let you know, doctor, how the case goes on, and perhaps you wouldn't mind turning it over a bit in the interval. Something might occur to you."

Thorndyke promised to think over the case, and when we had seen the superintendent launched down the stairs, we followed Polton up to the laboratory, where we each picked up one of the negatives and examined it against the light. I had already identified the seal by its shape—a vesica piscis or boat-shape—with the one that I had seen on Mr. Luttrell's finger. Now, in the photograph, enlarged three diameters, I could clearly make out the details. The design was distinctive and curious rather than elegant. The two triangular spaces at the ends were occupied respectively by a memento mori and a winged hour-glass and the central portion was filled by a long inscription in Roman capitals, of which I could at first make nothing.

"Do you suppose this is some kind of cryptogram?" I asked.

"No," Thorndyke replied. "I imagine the words were run together merely to economise space. This is what I make of it."

He held the negative in his left hand, and with his right wrote down in pencil on a slip of paper the following four lines of doggerel verse:

"Eheu alas how fast the dam fugaces
Labuntur anni especially in the cases
Of poor old blokes like you and me Posthumus
Who only wait for vermes to consume us."

"Well," I exclaimed, "it is a choice specimen; one of old Luttrell's merry conceited jests, I take it. But the joke was hardly worth the labour of engraving on a seal."

"It is certainly a rather mild jest," Thorndyke admitted. "But there may be something more in it than meets the eye."

He looked at the inscription reflectively and appeared to read it through once or twice. Then he replaced the negative in the drying rack, and, picking up the paper, slipped it into his pocket-book.

"I don't quite see," said I, "why Miller brought this case to us or what he wants you to think over. In fact, I don't see that there is a case at all."

"It is a very shadowy case," Thorndyke admitted. "Miller has done a good deal of guessing, and so has Badger; and it may easily turn out that they have found a mare's nest. Nevertheless there is something to think about."

"As, for instance—?"

"Well, Jervis, you saw the men; you saw how they behaved; you have heard Miller's story and you have seen Mr. Luttrell's seal. Put all those data together and you have the material for some very interesting speculation, to say the least. You might even carry it beyond speculation."

I did not pursue the subject, for I knew that when Thorndyke used the word "speculation," nothing would induce him to commit himself to an opinion. But later, bearing in mind the attention that he had seemed to bestow on Mr. Luttrell's schoolboy verses, I got a print from the negative and studied the foolish lines exhaustively. But if it had any hidden meaning—and I could imagine no reason for supposing that it had—that meaning remained hidden; and the only conclusion at which I could arrive was that a man of Luttrell's age might have known better than to write such nonsense.

The superintendent did not leave the matter long in suspense. Three days later he paid us another visit. and half-apologetically reopened the subject.

"I am ashamed to come badgering you like this," he said, "but I can't get this case out of my head. I've a feeling that we ought to get a move of some kind on. And, by the way—though that is nothing to do with it—I've copied out the stuff on that seal and I can't make any sense of it. What the deuce are fugaces? I suppose 'vermes' are worms, though I don't see why he spelt it that way."

"The verses," said Thorndyke, "are apparently a travesty of a Latin poem; one of the odes of Horace which begins:

"'Eheu fugaces, Postume, Postume, Labuntur anni,'

"which means, in effect, 'Alas! Postume, the flying years slip by.'"

"Well," said Miller, "any fool knows that—any middle-aged fool, at any rate. No need to put it into Latin. However, it's of no consequence. To return to this case; I've got an authority to look over Luttrell's premises—not to pull anything about, you know, just to look round. I called in on my way here to let the caretaker know that I should be coming in later. I thought that perhaps you might like to come with me. I wish you would, doctor. You've got such a knack of spotting things that other people overlook."

He looked wistfully at Thorndyke, and as the latter was considering the proposal, he added: "The caretaker mentioned a rather odd circumstance. It seems that he keeps an eye on the electric meters in the building and that he has noticed a leakage of current in Mr. Luttrell's. It is only a small leak; about thirty watts an hour. But he can't account for it in any way. He has been right through the premises to see if any lamp has been left on in any of the rooms. But all the switches are off everywhere, and it can't be a short circuit. Funny, isn't it?"

It was certainly odd, but there seemed to me nothing in it to account for the expression of suddenly awakened interest that I detected in Thorndyke's face. However, it evidently had some special significance for him, for he asked almost eagerly "When are you making your inspection?"

"I am going there now," replied Miller, and he added coaxingly, "Couldn't you manage to run round with me?"

Thorndyke stood up. "Very well," said he. "Let us go together. You may as well come, too, Jervis, if you can spare an hour."

I agreed readily, for my colleague's hardly disguised interest in the inspection suggested a definite problem in his mind; and we at once issued forth and made our way by Mitre Court and Fetter Lane to the abode of the missing dealer, an old-fashioned house near the end of Thavies Inn.

"I've been over the premises once," said Miller, as the caretaker appeared with the keys, "and I think we had better begin the regular inspection with the offices. We can examine the stores and living-rooms afterwards."

We accordingly entered the outer office, and as this was little more than a waiting-room, we passed through into the private office, which had the appearance of having been used also as a sitting-room or study. It was furnished with an easy-chair, a range of book-shelves and a handsome bureau book-case, while in the end wall was the massive iron door of the strong-room. On this, as the chief object of interest, we all bore down, and the superintendent expounded its peculiarities.

"It is quite a good idea," said he, "this letter-lock. There's no keyhole—though a safe-lock is pretty hopeless to pick even if there was a keyhole—and no keys to get lost. As to guessing what the 'open sesame' may be—well, just look at it. You could spend a lifetime on it and be no forrader."

The puzzle lock was contained in the solid iron door post, through a slot in which a row of fifteen A's seemed to grin defiance on the would-be safe-robber. I put my finger on the milled edges of one or two of the letters and rotated the discs, noticing how easily and smoothly they turned.

"Well," said Miller, "it's no use fumbling with that. I'm just going to have a look through his ledger and see who his customers were. The book-case is unlocked. I tried it last time. And we'd better leave this as we found it."

He put back the letters that I had moved, and turned away to explore the book-case; and as the letter-lock appeared to present nothing but an insoluble riddle, I followed him, leaving Thorndyke earnestly gazing at the meaningless row of letters.

The superintendent glanced back at him with an indulgent smile.

"The doctor is going to work out the combination," he chuckled. "Well, well. There are only forty billion changes and he's a young man for his age."

With this encouraging comment, he opened the glass door of the book-case, and reaching down the ledger, laid it on the desk-like slope of the bureau.

"It is a poor chance," said he, opening the ledger at the index, "but some of these people may be able to give us a hint where to look for Mr. Luttrell, and it is worth while to know what sort of business he did."

He ran his finger down the list of names and had just turned to the account of one of the customers when we were startled by a loud click from the direction of the strong-room. We both turned sharply and beheld Thorndyke grasping the handle of the strong-room door, and I saw with amazement that the door was now slightly ajar.

"God!" exclaimed Miller, shutting the ledger and starting forward, "he's got it open!" He strode over to the door, and directing an eager look at the indicator of the lock, burst into a laugh. "Well, I'm hanged!" he exclaimed. "Why, it was unlocked all the time! To think that none of us had the sense to tug the handle! But isn't it just like old Luttrell to have a fool's answer like that to the blessed puzzle!"

I looked at the indicator, not a little astonished to observe the row of fifteen A's, which apparently formed the key combination. It may have been a very amusing joke on Mr. Luttrell's part, but it did not look very secure. Thorndyke regarded us with an inscrutable glance and still grasped the handle, holding the door a bare half-inch open.

"There is something pushing against the door," said he. "Shall I open it?

"May as well have a look at the inside," replied Miller. Thereupon Thorndyke released the handle and quickly stepped aside. The door swung slowly open and the dead body of a man fell out into the room and rolled over on to its back.

"Mercy on us!" gasped Miller, springing back hastily and staring with horror and amazement at the grim apparition. "That is not Luttrell." Then, suddenly starting forward and stooping over the dead man, he exclaimed "Why, it is Shemmonds. So that is where he disappeared to. I wonder what became of Luttrell?"

"There is somebody else in the strong-room," said Thorndyke; and now, peering in through the doorway, I perceived a dim light, which seemed to come from a hidden recess, and by which I could see a pair of feet projecting round the corner. In a moment Miller had sprung in, and I followed. The strong-room was L shaped in plan, the arm of the L formed by a narrow passage at right angles to the main room. At the end of this a single small electric bulb was burning, the light of which showed the body of an elderly man stretched on the floor of the passage. I recognised him instantly in spite of the dimness of the light and the disfigurement caused by a ragged wound on the forehead.

"We had better get him out of this," said Miller, speaking in a flurried tone, partly due to the shock of the horrible discovery and partly to the accompanying physical unpleasantness, "and then we will have a look round, This wasn't just a mere robbery. We are going to find things out."

With my help he lifted Luttrell's corpse and together we carried it out, laying it on the floor of the room at the farther end, to which we also dragged the body of Shemmonds.

"There is no mystery as to how it happened," I said, after a brief inspection of the two corpses. "Shemmonds evidently shot the old man from behind with the pistol close to the back of the head. The hair is all scorched round the wound of entry and the bullet came out at the forehead."

"Yes," agreed Miller, "that is all clear enough. But the mystery is why on earth Shemmonds didn't let himself out. He must have known that the door was unlocked. Yet instead of turning the handle, he must have stood there like a fool, battering at the door with his fists. Just look at his hands."

"The further mystery," said Thorndyke who, all this time, had been making a minute examination of the lock both front without and within, "is how the door came to be shut. That is quite a curious problem."

"Quite," agreed Miller. "But it will keep. And there is a still more curious problem inside there. There is nearly all the swag from that Colchester robbery. Looks as if Luttrell was in it."

Half reluctantly he re-entered the strong-room and Thorndyke and I followed. Near the angle of the passage he stooped to pick up an automatic pistol and a small, leather book, which he opened and looked into by the light of the lamp. At the first glance he uttered an exclamation and shut the book with a snap.

"Do you know what this is?" he asked, holding it out to us. "It is the nominal roll, address book and journal of the gang. We've got them in the hollow of our hand; and it is dawning upon me that old Luttrell was the managing director whom I have been looking for so long. Just run your eyes along those shelves. That's loot; every bit of it. I can identify the articles from the lists that I made out."

He stood looking gloatingly along the shelves with their burden of jewellery, plate and other valuables. Then his eye lighted on a drawer in the end wall just under the lamp; an iron drawer with a disproportionately large handle and bearing a very legible label inscribed "unmounted stones."

"We'll have a look at his stock of unmounted gems," said Miller; and with that he bore down on the drawer, and seizing the handle, gave a vigorous pull. "Funny," said he. "It isn't locked, but something seems to be holding it back."

He planted his foot on the wall and took a fresh purchase on the handle. "Wait a moment, Miller," said Thorndyke; but even as he spoke, the superintendent gave a mighty heave; the drawer came out a full two feet; there was a loud click, and a moment later the strong-room door slammed.

"Good God!" exclaimed Miller, letting go the drawer, which immediately slid in with another click. "What was that?"

"That was the door shutting," replied Thorndyke. "Quite a clever arrangement; like the mechanism of a repeater watch. Pulling out the drawer wound up and released a spring that shut the door. Very ingenious."

"But," gasped Miller, turning an ashen face to my colleague, "we're shut in."

"You are forgetting," said I—a little nervously, I must admit—"that the lock is as we left it."

The superintendent laughed, somewhat hysterically. "What a fool I am!" said he. "As bad as Shemmonds. Still we may as well—" Here he started along the passage and I heard him groping his way to the door, and later heard the handle turn. Suddenly the deep silence of the tomb-like chamber was rent by a yell of terror.

"The door won't move! It's locked fast!"

On this I rushed along the passage with a sickening fear at my heart. And even as I ran, there rose before my eyes the horrible vision of the corpse with the battered hands that had fallen out when we opened the door of this awful trap. He had been caught as we were caught. How soon might it not be that some stranger would be looking in on our corpses.

In the dim twilight by the door I found Miller clutching the handle and shaking it like a madman. His self-possession was completely shattered. Nor was my own condition much better. I flung my whole weight on the door in the faint hope that the lock was not really closed, but the massive iron structure was as immovable as a stone wall. I was nevertheless, gathering myself up for a second charge when I heard Thorndyke's voice close behind me.

"That is no use, Jervis. The door is locked. But there is nothing to worry about."

As he spoke, there suddenly appeared a bright circle of light from the little electric lamp that he always carried in his pocket. Within the circle, and now clearly visible, was a second indicator of the puzzle lock on the inside of the door-post. Its appearance was vaguely reassuring, especially in conjunction with Thorndyke's calm voice; and it evidently appeared so to Miller, for he remarked, almost in his natural tones:

"But it seems to be unlocked still. There is the same AAAAAA that it showed when we came in."

It was perfectly true. The slot of the letter-lock still showed the range of fifteen A's, just as it had when the door was open. Could it be that the lock was a dummy and that there was some other means of opening the door? I was about to put this question to Thorndyke when he put the lamp into my hand, and, gently pushing me aside, stepped up to the indicator.

"Keep the light steady, Jervis," said he, and forthwith he began to manipulate the milled edges of the letter discs, beginnings as I noticed, at the right or reverse end of the slot and working backwards. I watched him with feverish interest and curiosity, as also did Miller, looking to see some word of fifteen letters develop in the slot. Instead of which, I saw, to my amazement and bewilderment my colleague's finger transforming the row of A's into a succession of M's, which, however, were presently followed by an L and some X's. When the row was completed it looked like some remote, antediluvian date set down in Roman numerals.

"Try the handle now, Miller," said Thorndyke.

The superintendent needed no second bidding. Snatching at the handle, he turned it and bore heavily on the door. Almost instantly a thin line of light appeared at the edge; there was a sharp click, and the door swung right open. We fell out immediately—at least the superintendent and I did—thankful to find ourselves outside and alive. But, as we emerged, we both became aware of a man, white-faced and horror-stricken of aspect, stooping over the two corpses at the other end of the room. Our appearance was so sudden and unexpected—for the massive solidity of the safe-door had rendered our movements inaudible outside—that, for a moment or two, he stood immovable, staring at us, wild-eyed and open-mouthed. Then, suddenly, he sprang up erect, and, darting to the door, opened it and rushed out with Miller close on his heels.

He did not get very far. Following the superintendent, I saw the fugitive wriggling in the embrace of a tall man on the pavement, who, with Miller's assistance, soon had a pair of handcuffs snapped on the man's wrists and then departed with his captive in search of a cab.

"That's one of 'em, I expect," said Miller, as we returned to the office; then, as his glance fell on the open strong-room door, he mopped his face with his handkerchief. "That door gives me the creeps to look at it," said he. "Lord I what a shake-up that was! I've never had such a scare in my life. When I heard that door shut and I remembered how that poor devil, Shemmonds, came tumbling out—phoo!" He wiped his brow again, and, walking towards the strong-room door, asked: "By the way, what was the magic word after all?" He stepped up to the indicator, and, after a quick glance, looked round at me in surprise. "Why!" he exclaimed, "blow me if it isn't AAAA still! But the doctor altered it, didn't he?"

At this moment Thorndyke appeared from the strong-room, where he had apparently been conducting some explorations, and to him the superintendent turned for an explanation.

"It is an ingenious device," said he; "in fact, the whole strong-room is a monument of ingenuity, somewhat misapplied, but perfectly effective, as Mr. Shemmonds's corpse testifies. The key-combination is a number expressed in Roman numerals, but the lock has a fly-back mechanism which acts as soon as the door begins to open. That was how Shemmonds was caught. He, no doubt purposely, avoided watching Luttrell set the lock—or else Luttrell didn't let him—but as he went in with his intended victim, he looked at the indicator and saw the row of A's, which he naturally assumed to be the key. Then, when he tried to let himself out, of course, the lock wouldn't open."

"It is rather odd that he didn't try some other combinations," said I.

"He probably did," replied Thorndyke, "but when they failed he would naturally come back to the A's, which be had seen when the door was open. This is how it works."

He shut the door, and then, closely watched by the superintendent and me, turned the milled rims of the letter-discs until the indicator showed a row of numerals thus: MMMMMMMCCCLXXXV. Grasping the handle, he turned it and gave a gentle pull, when the door began to open. But the instant it started from its bed, there was a loud click and all the letters of the indicator flew back to A.

"Well, I'm jiggered!" exclaimed Miller. "It must have been an awful suck-in for that poor blighter, Shemmonds. Took me in, too. I saw those A's and the door open, and I thought I knew all about it. But what beats me, doctor, is how you managed to work it out. I can't see what you had to go on. Would it be allowable to ask how it was done?"

"Certainly," replied Thorndyke "but we had better defer the explanation. You have got those two bodies to dispose of and some other matters, and we must get back to our chambers. I will write down the key-combination, in case you want it, and then you must come and see us and let us know what luck you have had."

He wrote the numerals on a slip of paper, and when he had handed it to the superintendent, we took our leave.

"I find myself," said I, as we walked home, "in much the same position as Miller. I don't see what you had to go on. It is clear to me that you not only worked out the lock-combination—from the seal inscription, as I assume—but that you identified Luttrell as the director of the gang. I don't, in the least, understand how you did it."

"And yet, Jervis," said he, "it was an essentially simple case. If you review it and cast up the items of evidence, you will see that we really had all the facts. The problem was merely to co-ordinate them and extract their significance. Take first the character of Luttrell. We saw the man in company with another, evidently a fairly intimate acquaintance. They were being shadowed by a detective, and it is pretty clear that they detected the sleuth, for they shook him off quite neatly. Later, we learn from Miller that one of these men is suspected to be a member of a firm of swell burglars and that the other is a well-to-do, rather eccentric and very miscellaneous dealer, who has a strong-room fitted with a puzzle lock. I am astonished that the usually acute Miller did not notice how well Luttrell fitted the part of the managing director whom he was looking for. Here was a dealer who bought and sold all sorts of queer but valuable things, who must have had unlimited facilities for getting rid of stones, bullion and silver, and who used a puzzle lock. Now, who uses a puzzle lock? No one, certainly, who can conveniently use a key. But to the manager of a gang of thieves it would be a valuable safeguard, for he might at any moment be robbed of his keys, and perhaps made away with. But he could not be robbed of the secret passwords and his possession of it would be a security against murder. So you see that the simple probabilities pointed to Luttrell as the head of the gang.

"And now consider the problem of the lock. First, we saw that Luttrell wore on his left hand a huge, cumbrous seal ring, that he carried a Coddington lens on his watch-guard, and a small electric lamp in his pocket. That told us very, little. But when Miller told us about the lock and showed us the squeeze of the seal, and when we saw that the seal bore a long inscription in minute lettering, a connection began to appear. As Miller justly observed, no man—especially no elderly man—could trust the key combination exclusively to his memory. He would carry about him some record to which he could refer in case his memory failed him. But that record would hardly be one that anybody could read, or the secrecy and safety of the lock would be gone. It would probably be some kind of cryptogram; and when we saw this inscription and considered it in conjunction with the lens and the lamp, it seemed highly probable that the key-combination was contained in the inscription; and that probability was further increased when we saw the nonsensical doggerel of which the inscription was made up. The suggestion was that the verses bad been made for some purpose independent of their sense. Accordingly I gave the inscription very careful consideration.

"Now we learned from Miller that the puzzle lock had fifteen letters. The key might be one long word, such as 'superlativeness', a number of short words, or some chemical or other formula. Or it was possible that it might be of the nature of a chronogram. I have never heard of chronograms being used for secret records or messages, but it has often occurred to me that they would be extremely suitable. And this was an exceptionally suitable case."

"Chronogram," said I. "Isn't that something connected with medals?"

"They have often been used on medals," he replied. "In effect, a chronogram is an inscription some of the letters of which form a date connected with the subject of the inscription. Usually the date letters are or cut larger than the others for convenience in reading, but, of course, this is not essential. The principle of a chronogram is this. The letters of the Roman alphabet are of two kinds: those that are simply letters and nothing else, and those that are numerals as well as letters. The numeral letters are M = a thousand, D = five hundred, C = one hundred, L = fifty, X = ten, V = five, and I = one. Now, in deciphering a chronogram, you pick out all the numeral letters and add them up without regard to their order. The total gives you the date.

"Well, as I said, it occurred to me that this might be of the nature of a chronogram; but as the lock had letters and not figures, the number, if there was one, would have to be expressed in Roman numerals, and it would have to form a number of fifteen numeral letters. As it was thus quite easy to put my hypothesis to the test, I proceeded to treat the inscription as a chronogram and decipher it; and behold! it yielded a number of fifteen letters, which, of course, was as near certainty as was possible, short of actual experiment."