"On the contrary, I can't possibly know too much, and the particulars can't possibly be too minute. Nine cases out of ten I bring to an issue by means of a triviality. You were saying a little while back that there were almost no visitors at Mr. Mason's house; but you said 'almost,' and that means there are some. Who are they?"

"Very occasionally—rarely, in fact—there are one or two members of learned societies with whom he had been in correspondence, or who are old friends. There is a Professor Hutton and a Dr. Burge, I believe; but they don't appear once in six months; and there is Mr. Everard Myatt, who is more frequent. He does not profess to be a great man of science, but he is interested in chemistry as an amateur, and is, I fancy, a sort of disciple of Mason's. He has noticed a sad difference in Mason just lately, and he even called on me yesterday, though I hardly knew him by sight, in the hope that I would back up his urgent suggestion that Mason should go off for a change and a rest. Beyond these I don't think I know of a single visitor. But here we are at the Megatherium."



II

Mr. Jacob Mason's house stood in its own grounds in a quiet suburban road. It was not a very large house, but it straggled about comfortably in the manner of detached houses built in the suburbs at a time when space was less valuable than now, and it consisted of two floors only. The front door was not far from the road, and was clearly visible to passengers who might chance to look through either of the two iron gates that opened one on each end of the semi-circular drive.

All these things Martin Hewitt noticed as the Rev. Mr. Potswood pushed open one of these gates, and the two walked up the drive. The front door stood in a portico, and a French window gave access to the roof of this portico from a bedroom or dressing-room. As Hewitt and his companion approached the house the French window was pushed open, and a man appeared—a middle-aged, slightly stoutish man with a short, grey beard; commonplace enough in himself, but now convulsed with noisy anger, shaking his fists and stamping on the portico-roof.

"Get out!" he shouted. "Don't come near my house again, or I'll have you flung out! Go away and take your friends with you! D'you hear? Go away, sir, and don't come here annoying me! Go! Go at once!"

Mr. Potswood absolutely staggered with amazement. "Why," he gasped, "it's Mason! He's mad—clean mad! Why, Mason, my poor friend, don't you know me?"

"Get out, I say!" cried Mason. "Give me no more of your talk! I won't have you here!" And now Hewitt caught a glimpse of a girl's face at the window behind the man—a pale and handsome face, drawn with anxiety and fear.

Hewitt seized the clergyman quickly by the arm. "Come," he whispered hurriedly, "come away at once. There is a reason for this. Get away at once. If you can answer back angrily, do so, but at any rate, come away."

He hurried back to the gate, half dragging the astounded rector, who was all too honest a soul to be able to counterfeit an anger he did not feel, even if his amazement had not made him speechless. Hewitt closed the gate behind him and said as he walked, "Where is the rectory? We will go there. He may have sent a message while you were out."

Mechanically the rector took the first turning. "But he's mad!" he protested. "Mad, poor fellow! Merciful heavens, Mr. Hewitt, his whole tale must have been a delusion! A mere madman's fancy! Poor fellow! We must go back, Mr. Hewitt—we really must! We can't leave that poor girl there alone with a raving maniac!"

"No," Hewitt insisted, "come to the rectory. That is no madness, Mr. Potswood. Couldn't you see the colour of the man under the eyes, and the shaking of his beard? That was not anger and it was not madness. It was terror, Mr. Potswood—sheer, sick terror! Terror, or some emotion very much like it."

"But, if terror, why that outburst? What does it mean? If it were terror, why not rather welcome our company and help?"

"Don't you see, Mr. Potswood?" answered Hewitt. "Don't you guess? Mason is watched, and he knows it! He was acting his anger before unseen eyes—and he knew they were on him!"

"God be merciful to us all," ejaculated the clergyman. "Poor man—poor sinner! What is this unspeakable thing which has him in its clutches? What had he done to give himself over to such a power?"

"We can tell nothing, and guess nothing, as yet," Hewitt answered. "Let us see if he has sent you a message. It seems likely. If he has it may help us. If not—then I think we must do something decisive at once. But don't hurry so! It is hard to restrain one's self, I know, but there may be eyes on us, Mr. Potswood, and we must not seem to be persisting in our errand."

So they went through the quiet streets for the two or three furlongs that seemed so many miles to the good parson. Arrived at the rectory, Mr. Potswood pushed impatiently through the gate, and was hurrying toward the house, when he perceived a bent little old man standing among some shrubs with his own gardener, who was digging.

"There's Mason's gardener!" the rector exclaimed, and went to meet him.

The old man touched his hat, looked sharply towards Hewitt, who was waiting near the rectory door, and then disappeared round a corner of the house, the rector following. In a few seconds Mr. Potswood reappeared, with a slip of paper in his hand. "Here," he said, "see this! The old man was told to give it to nobody but me, and in nobody else's presence. He's been waiting since one o'clock."

Scrawled on the paper, in trembling and straggling letters, were these words:—

/# "You must not bring Mr. Martin Hewitt to my house this afternoon. I am watched. It is hopeless. Do not desert me. Bring him to-night after dark at eight. I shall want his best skill, and you shall know all. After dark. Come to the back gate in the lane, which will be ajar, and through the conservatory at the side, where my niece will be waiting at eight, after dark. Burn this and do not let it out of your sight first. Send a line by this man to say you will do as I ask, but do not say what it is, for fear of accidents. Send at once. Do come at eight, with Mr. Hewitt." #/

"We must do as he says," remarked Hewitt. "We know nothing of this matter, and we must be guided till we do. Just write an unsigned note—'All shall be as you request,' or words to that effect, and be sure the man gives it to him. Let him out behind through the churchyard, if possible, and tell him not to go straight from one house to the other. Is he an intelligent man?"

"Yes—uncommonly shrewd, I believe. He says he can't have been followed. He knows several gardeners hereabout, and he seems to have called on each of them on his way—in at the front of the garden and out at the back each time, after a few minutes' conversation. Gipps is rather a cunning old fellow."

"Ah," said Hewitt admiringly, "that's the sort of messenger I often want. I'll give him half a crown for himself and the money to pay for a telegram on his way. He knows nothing essential, of course?"

"No—only that his master is in some sort of trouble, and warned him that he might be followed."

"That is good. I shall telegraph to Detective-Inspector Plummer, of Scotland Yard. All right—I quite understand that all I have heard is confidential. I shall tell Plummer nothing till I may—indeed, as yet I have very little to tell that would help him. But I think it will be well to have the police within call—we may want them at a moment's notice; I have no police powers, you see, and Plummer has the Denson case in hand. I will ask him to be here, at this house, before a quarter to eight, if you will allow me."

And so the telegram went to Plummer, and Hewitt, accepting the rector's invitation to an early dinner before starting on their visit, resigned himself to wait. He did not like the waste of time, as he frankly told Mr. Potswood. He would have preferred to see Mason at once, at any risk, and to take what means he thought necessary without delay. But as it seemed that the risk was to be chiefly Mason's, and as Mason knew all of which both he and the rector were ignorant, Mason must be allowed to choose his own time.

The excellent Mr. Potswood endured agonies of suspense, though he also insisted that Mason's wishes must be observed exactly. "What is it all—what can it be?" he ejaculated again and again. "What dreadful influence can thus compass a man about, here in London, in these times?"

* * * * *

It was autumn, and night fell early. Dinner was over at last, and they had scarcely left the table when Plummer arrived, anxious and eager.

"You'll have to trust me a little, Plummer," Hewitt said, when he had made him known to the rector. "I can tell you nothing now—know nothing, in fact, or very little more than nothing. The fact is, I'm going to see a man who promises information to me alone, in confidence, as his client, and I don't know how long I may have to keep you in the dark. But this is where the trail lies hot, and I know that's where you want to be. More, if you're wanted suddenly you'll be at hand. You have a man or two with you, I suppose, as I suggested?"

"Three of the best of them. They will follow us up. Is it far?"

"No, close enough. It is a house in a walled garden—not a high wall. We go in at a gate from the lane behind, and I think you should wait at that gate, and put your men at hand. We mustn't go in as a crowd. The rector had better go first, and you and I will follow on the opposite side of the road."

So the procession was formed, and it was still some three minutes short of eight o'clock when Hewitt and Plummer joined the clergyman at the door in the garden wall behind Mason's house. The door was ajar as had been promised in Mason's note. Leaving Plummer on guard without, Martin Hewitt and the rector stepped as silently as possible through the little kitchen garden and across a strip of lawn toward where a dull light illuminated the conservatory, at the right-hand end of the house. The door of the conservatory was ajar also, and this the rector pushed open.

"Miss Creswick!" the rector called, in a loud whisper. "Miss Creswick!" And with that a girl appeared within.

"Oh, Mr. Potswood," she said, "I'm so glad you've come! I can't think what's wrong with poor uncle! I'm afraid he must be going mad! He is terrified at something, and he has been getting worse, till he could hardly speak or walk. Dr. Lawson has been—about an hour ago, and since then uncle has been much quieter, in his study."

They were entering the dimly-lighted drawing-room now. "Dr. Lawson?" queried the rector. "Rather an unusual visitor, isn't he? How long has he been gone?"

Miss Creswick flushed slightly through all her paleness and grief. "I don't know," she said. "He let himself out, I fancy. He said he could not stay long when he came, but I didn't hear him go; I have been upstairs, and the servants are in the kitchen—they say uncle's mad, and I'm really afraid he is!"

They left the drawing-room, and walked along the corridor and the hall to the opposite side of the house, where the study lay. Miss Creswick tapped gently at the door, but there was no answer. She tapped again, louder, and then came the faint sound of a quick step on the carpet, and then a slight scraping noise, as when a door is closed over a carpet it will scarcely pass. "That's the window into the garden," said Miss Creswick. "Why is he going out? Uncle! Uncle Jacob!"

But now the silence was wholly unbroken. Hewitt snatched quickly at the door-handle. "Locked!" he said. "Come—the quickest way into the garden!"

They ran out at the front door, and round toward the study window. It was a French window, exactly at the opposite end of the house to the conservatory, and now the gas-light streamed out through one half of it, which stood curtainless and ajar, while the curtain was drawn across the other half. Hewitt was the least familiar with the place, but he was quickest on his legs, and more seriously alarmed than the others. He reached the window first—and instantly turned and thrust the rector back against Miss Creswick. "Quick! take her away," he said; "we are too late!" and in the same moment, even as Hewitt dashed over the threshold, he snatched a whistle from his pocket, and blew his hardest.

There on the floor lay Mason, his face dreadful and staring and black; tight in his neck was the band of a tourniquet, and fresh and wet on his forehead was the Red Triangle.

Hewitt snatched at the screw of the tourniquet behind the neck, and loosened it as quickly as hands could turn. But it was too late. Too late, the examining surgeon afterwards said, by a quarter of an hour.

Plummer was at the window with his men at his heels even before the tourniquet was half unscrewed.

"Round the wall of the garden," shouted Hewitt, "and whistle up the police! He's only this moment out!"

The house was alive with shouts and screams. The rector came running back, and Hewitt, busy with his useless attempt at restoration, called now for a doctor. People were scampering in the street, and Hewitt left the victim to the care of the rector, and himself joined Plummer, all in fewer seconds than it may be told in.

But Plummer and his men were beaten, for nothing—not so much as a moving shadow—was seen in the garden or about the walls. Worse, the general trampling would obliterate possible tracks. Plummer set a guard of police about the wall, and came in for consultation with Hewitt.

The body was carried into another room, and Hewitt and Plummer began an examination of the study.

"No signs of a struggle," commented Plummer, "and there was no noise, they say. That's very odd."

"From what I have seen and heard to-day," said Hewitt, "it is as I should have expected. I believe the man was almost killed by terror before he was strangled—dazed, stricken dumb, paralysed, deafened by it—everything but blinded, poor wretch. And to have been blinded would have been a mercy."

And then, as they made their examination systematically, calmly and without flurry, Hewitt told the whole tale of his day's adventures, together with all he had heard from the rector. "The man's dead," he said, "and his confidence is at an end. Indeed, I never had it—the case, so far as I am concerned, is over before I have even touched it. I haven't had a chance, Plummer; and the thing is deep and dark, deep and dark. Oh, if only the man had let me come to him in the daylight, spite of all! This might all have been averted.... There has been a close search here, too. See how everything is turned over. But, stay!"

A low fire smouldered in the grate, and on it lay ashes of many burnt papers. Hewitt passed the shovel carefully under these ashes, lifted them out and placed them gently on the table under the light of the gas-pendant.

"I must leave you," said Plummer. "There'll be an inspector here from the station in a moment—he won't interfere with you, and if anybody can get information out of this room it's you. The next thing for me is plain. I must make sure of Dr. Lawson, if he can be found."

"That is quite right, without a doubt," Hewitt responded. "I may find anything or nothing in this room, and, meanwhile, he was the last person known to have been here, and the only visitor, and he was not heard to go out, unless we heard him go when we were outside the study door. More, it was plainly some one familiar with the place who was able to get away so quickly by the window and the garden."

"And his interest in getting rid of Mason, too—the girl of age in a few months, and all obstacles to getting hold of her, and her money, removed. And—and the surgical tourniquet, the Chinese colour and everything!"

"Quite right, you must make sure of him, as you say. You will get his address from the rector. Meanwhile I'll try to begin my little contribution to the case—to begin it as best I can, after all the chances have made it useless."



III

It was after nine when Plummer returned. The rector had just rejoined Hewitt in the study, having left poor Miss Creswick, utterly broken down, in her room, in charge of a scarcely less terrified servant. Plummer tapped, and pushed the study door open.

"That's done clean and sure enough," he said, with professional calmness. "And he's a cool hand, is that Dr. Lawson. But have you found anything more? We shall want all we can get."

"We shall," Hewitt assented, "and we shall find more than we've got now, or I'm grievously mistaken. But tell me first what you've done."

He removed the blotting pad, on which the paper ashes still lay, and very carefully shut it away in a wide drawer where no draught could disturb it; he also shut another drawer which stood open.

"We had no difficulty in finding Dr. Lawson," Plummer began. "We met him, in fact, leaving his surgery. I went back with him into the gas-light, and there put it to him plump. Well, he was staggered, badly. Any man would be, of course. But he pulled himself together wonderfully soon, and the first thing he said was that he was just on his way to Mason's house. I thought at first, of course, that he meant to deny that he had been there already, and I gave him the usual warning about what he said being used in evidence. But he went on, and I've got it all safely noted. He admitted that he had been here, at about seven o'clock or just before, and he said he came because Mr. Mason sent for him. That doesn't seem likely, does it, on the facts as we know them?"

"Why, no," said the rector. "The last time he was here he was ordered out, and I know of no reason why he should have been asked to come to-day. We must ask if anybody was sent."

"I have asked," replied Plummer, "just now, and none of the servants was sent. But Lawson's story is that he was sent for and came, though he said he shouldn't say what Mason wanted to see him about till he knew more of the case. Looks as though he hadn't quite got his story ready yet, doesn't it? He had thought over the point about not being seen to go away, though; he said he had let himself out at about half-past seven, being familiar with the ways of the house. And he said that Mason was rather unwell—nervously upset—when he left him, but that was all."

"It's terrible," said the rector, "terrible. It seems impossible to believe it of young Lawson; and yet—and yet!" And then after a pause—"Good heavens!" he burst out again. "Why, I only realise it now! There is the other crime, too! Denson! Two murders! Two—and most certainly by the same hand! Mr. Plummer, I can't believe it! Oh, there's more behind, more behind, Mr. Hewitt."

"There is more," said Hewitt, "as you will see when I tell you the little I have been able to ascertain. There is more behind, though I see little of it yet. First——"

There was a sharp knock at the front door, followed by a ring, muffled in the distant kitchen. Hewitt started up. "Who is this late visitor at this unvisited house?" he said. "If it is the police, well enough. But if anybody else—anybody—you may call me Doctor, or anything you please, except Martin Hewitt. Don't forget that!"

There were hurried steps in the hall, a question or two, and the study door was pushed open. Two servants—they would not venture from the kitchen singly this dreadful night—made a confused announcement of "Mr. Myatt," and were instantly pushed aside by Mr. Myatt himself, anxious and agitated.

The late Mr. Mason's closest scientific friend was a palish, black-bearded man, of above middle height, with stooping shoulders and a very quick pair of eyes. There was something about his face that somehow reminded Hewitt of portraits he had seen of John Knox, and yet it was not such a face as his; it seemed oddly unlike in its very likeness.

"What is this dreadful news, Mr. Potswood?" he cried. "I heard people talking in the next street on my way home. Is it true? But the servants have told me so. They say our poor friend—but there has been an arrest, hasn't there?"

The rector nodded gravely.

"And who? Tell me about it, Mr. Potswood—tell me!"

"I think I must see how Miss Creswick is doing," said Hewitt, speaking across to Plummer and making for the door.

"Certainly, doctor, certainly!" answered Plummer with a nod.

Hewitt closed the door behind him, leaving the rector in the full tide of his account of the day's events; but Hewitt's way took him to the kitchen, where the servants were cowering and whispering together, frightened and bewildered.

"Is there any paint or varnish of any sort in the place?" he asked sharply. "Give me anything there is—black, if possible—and a brush, quickly."

"There's—there's Brunswick black, sir, for the stove," said the cook.

"That will do; be quick. Oh, there's Gipps, the gardener! You're just the man I want, Gipps. Come and find me a board or a plank, quick as you please!" And Hewitt pushed the old gardener before him into the garden by the kitchen door.

* * * * *

A quarter of an hour later, Mr. Everard Myatt, having heard all that was to be told of his friend's terrible death and the arrest of Mr. Lawson, turned to go, meeting Hewitt at the study door on his way.

"And how is poor Miss Creswick by now, doctor?" he asked anxiously.

Hewitt shook his head. "No better than you could expect," he said, "but, on the whole, no worse. She mustn't be seen to-night, of course, but, perhaps, if you could call round in the morning with the rector——"

"Of course—of course! Poor girl—and Dr. Lawson suspected, too—what a terrible blow for her! Anything I can do, doctor, of course, as I said to Mr. Potswood—anything I can do I will do as gladly as such sad circumstances permit."

The rector had been coming to the door with Mr. Myatt, but Plummer, catching a sign from Hewitt, restrained him unseen, and Hewitt and the visitor walked into the hall together.

"They have put out the light, it seems," Hewitt said. "I wonder why—unless people from the crowd have been coming into the garden and staring in through the glass panels. I wonder if we can find the door-handle. Yes, here it is. Dark outside, too! Good-night—mind how you go on the steps!"

Mr. Myatt checked and stumbled in the dark porch, and reached quickly downward.

"There's a board standing across the porch," he said.

"A board?" replied Hewitt. "So there is. Let me move it, or it'll upset somebody. Good-night!"

Mr. Myatt strode off into the dark night, and Hewitt, noiselessly lifting the board he had himself placed in position, hastened back to the study.

He swung up the board, all sticky and shiny with Brunswick black, and laid it across a spread newspaper, on the table. There on the top, in the midst of the black varnish, were the prints of all five finger-tips of a hand, where Mr. Myatt had felt for the obstruction in the porch.

Hewitt opened the drawer he had shut a little while back, and took therefrom a sheet of writing-paper. And when, with the lens from his pocket, he began to examine that paper in comparison with the finger-marks on the board, Plummer and the rector could see that there were also two distinct finger-marks on the paper and one faint one—all red. Plummer came to look.

"What's this?" he said. "Was this what you were going to tell us about?"

Hewitt did not reply for a few moments, but continued his examination. Then he rose and turned to Plummer.

"You've still got that piece of paper in your pocket, I suppose," he said, "with the little red smudges of colour put there by the police surgeon?"

"Yes—here it is," and the detective took it from his waistcoat pocket.

"Thanks," said Hewitt. "Now, see here. That is a little of the red stuff taken from the mark on Denson's forehead a week ago, and found to consist of vermilion, oil and wax. You have seen the second impression of that awful mark on the forehead of your poor friend Mason, Mr. Potswood, to-night. This room has been searched for papers before we began, and papers have been burnt. In the search this drawer was opened—containing, as you see, nothing but a supply of new headed note-paper. The note-paper was hastily lifted to see if anything else lay beneath, and here, on the bottom sheet, these finger-marks were left in that same adhesive, freely marking red—a sort of stuff that sticks to and marks whatever it touches. The hand that lifted that paper was the hand that impressed that ghastly mark; and the hand that left its print on this black varnish was Mr. Everard Myatt's! Now compare the two!"

Plummer had snatched the lens, and was narrowly comparing the marks ere Hewitt had well finished speaking.

"They are!" he cried, as the rector bent excitedly over him. "They are the same! See—forefinger and middle finger—the same, every line!"

"I needn't tell you," pursued Hewitt, "certainly I needn't tell Plummer, that that is the most certain and scientific method of identification known. The police know that—and use it. But now there is some more. You saw me take that charred paper from the fire. Sometimes words may be read on charred paper—it depends on the paper and the ink. Most of the cinders were too much broken to yield any information, though we may try again by daylight. But one was suggestive. See it!" Hewitt very carefully pulled out the flat drawer that held the cinders.

"You see," he went on, "that one—this—is different from the rest. It has retained its original form better, and has been less broken, because of being of thicker paper. It is a crumpled envelope. Look at the flap—it has never been closed down. Moreover, on that same flap you may read in embossed letters, still visible, part of the name of this house. Plain inference—this was an envelope intended for a letter never sent, and so crumpled up and dropped into the waste-paper basket. But why should such an apparently unimportant thing as that be carefully brought from the waste-paper basket and burnt? Somebody was anxious that the smallest scrap of paper evidencing a certain correspondence should be destroyed. But look closely at the front of the envelope—the ink shows a rather lighter grey than the paper. The address is incomplete—at any rate, no more than some of the first line and a little of the second is at all visible now; but it is plain that the first line begins with an E. The letters immediately following are not distinct, but next there is a capital M beginning a name which is clearly Myatt or Myall. Now, that is why, when Myatt came here, I took the first steps to hand to get an impression of his finger-tips, in order to compare them with the marks on that paper."

"But why," asked the astonished rector, "why did he come back?"

"Nothing but a bold measure to see how things were going—he came as his own spy, that's all. He's a keen and dangerous man. Don't you remember telling me how he called on you yesterday, though you hardly knew him by sight, merely to ask you to persuade Mason to take a holiday? It struck me as a little odd at the time. He was pumping you, Mr. Potswood—he wanted to find what Mason had been saying! And he is not alone—plainly he is not alone, for poor Mason knew they were watching everywhere. But come—this is no time for speculation. Plummer—you must hold him safely—we'll pick up evidence enough when you've got him. I wouldn't leave it, Plummer—I'd take him to-night!"

"You're right—right, as usual, Mr. Hewitt," Plummer agreed. "More especially as the rector was—well, a little incautious in talking to him just now."

"I? What did I say?" Mr. Potswood asked, astonished. "I had no suspicions—how could I have——"

"No, Mr. Potswood," the detective replied, "you had no suspicions, and for that very reason, in the excitement of the narrative, you called Mr. Martin Hewitt by his right name at least twice! And after I had called him 'doctor,' too!" he added regretfully.

"Is that so?" asked Hewitt.

The poor rector was sadly abashed. "But I really wasn't aware of it, Mr. Hewitt!" he protested. "I hardly think I could—but, there, perhaps I did! Of course, if Inspector Plummer remembers it——"

"He'll be off!" exclaimed Hewitt. "With that hint, and finding the black stuff on his hands, he'll smell a rat instantly! Come, Mr. Potswood—you can show us the nearest way to his house, at any rate! Come—we may get him yet!"

* * * * *

But the good rector's slip of the tongue was fatal, and Myatt was not yet to meet the fate that fitted him. The house was not far—less than a mile away. It was a detached house, but quite a small one—smaller than Mason's. Plummer blocked every exit with a man, but his caution was wasted. Myatt was gone.

There was the house and the furniture and two servants, just as it might have been any day in the year when Myatt was out for an hour. But now he was out for good. The police watched and waited all night, and all the next day; they waited and watched for a week, and the house was under observation after that, but Myatt never returned. He had made his plans, it was plain, for just such a flight, whenever the necessity might arise; and when he was assured that danger threatened, he simply vanished in the dark of a London night. Search brought no information—not a scrap of telltale paper lay in Calton Lodge—not a letter, not a line. Though, indeed, the police were to see more of Myatt's work yet—and so was Hewitt.

Dr. Lawson's detention did not last the night out. The unhappy Mason had indeed sent to him, by a chance messenger, having grown desperate in long waiting for the return of Gipps from the rectory. Mason was ready to call in any aid, to recall any of the friendships he had sacrificed in the past. But Lawson was long in coming, having received the note after a long professional round, and when at last he arrived, Mason was a little reassured by the promise of Hewitt's visit. Therefore, he did not tell the doctor so much as he might have done. Nevertheless, he talked wildly and vaguely, so that Dr. Lawson feared some disturbance of his reason. The doctor quieted and soothed him, however, and when he left he promised to return after his consultation hour at the surgery was over. He must have been watched away from the house, and then the blow fell that sealed for ever the lips of Jacob Mason.

Poor Miss Creswick was taken from the old house in which she could no longer remain, and for a few months she stayed at the rectory, tended lovingly by the rector's excellent wife—stayed there, in fact, till her wedding-day, which took place early the next year; so that for her and Dr. Lawson the tragedy ended in happiness, after all.

* * * * *

"God forgive me," cried the rector in the grey of the morning, when it became clear that Myatt had escaped—"God forgive me! Through my stupidity a horrible creature has been set loose in the world to work his diabolical will afresh!"

"Never mind," said Hewitt. "It was not stupidity, Mr. Potswood—nothing but your openness of character. You were not trained to the cunning that we must use in my profession. And there will be more than Myatt to take—he was not alone! It is plain that Mason was found to be wavering in whatever horrible allegiance he had bound himself, and he was watched. No, Myatt was not alone!"

"No, I fear not," replied the clergyman. "I fear not: there is horrible mystery still. The watching and besetting that terrified him so much; the fact that he seems to have yielded up his life without a struggle—and that with help so near; and the connection—what could it have been?—between Mason and the other victim—Denson. That is a deep mystery indeed! And that horrible sign! Mr. Hewitt, you have done much—but not all!"

"No," replied Martin Hewitt, "not nearly all. It is even doubtful whether or not it will be my lot to come across the thing again; but it will be in the hands of the police. And, after all, we have achieved something. For we know that if Myatt can be captured we shall be at the heart of the mystery."



THE CASE OF THE LEVER KEY



I

In some of the cases which we now know to have been connected with the Red Triangle, there was nothing, in the first place, to show any such association. In some of these cases the connection has become apparent only since the final clearing up of the whole mystery, and with these cases we have no present concern; but in others it revealed itself during the investigation of the case. It was to this second category that the next case belonged—the next at all connectible, that is, after that of the mysterious death of Mr. Jacob Mason and the flight of Everard Myatt.

The case was remarkable in other respects also; first, because in one of its features it had a resemblance to the case of Samuel's diamonds, which first brought the Red Triangle to Hewitt's notice; next, because in its course Hewitt encountered what he declared to be the most ingenious and baffling cryptogram that he had ever seen in the length of his strange experience; and thirdly, because I was the means of placing that cryptogram in his hands, owing to one of those odd chances that arise again and again in real life—are, indeed, so common as to pass almost unregarded—and yet might be thought improbable if offered in the guise of a mere story. Hewitt has often alluded to the curious persistence of such chances in his experience. I think I have elsewhere mentioned a certain police officer's prolonged search after a criminal for whose arrest he held a warrant, ending in the discovery—because of a misdirected call—that the man had been living all the time next door to himself; and I have also told of the other detective inspector, who, being sent in search of a criminal of whom he had but the meagrest and most unsatisfactory particulars, and whom he scarcely hoped ever to run down, actually fell over the man as he was leaving the office where he had received his information, in the doorway of which the fellow had stooped to tie his shoe-lace! But, as Hewitt would say, nothing but the exceptional nature of the surrounding circumstances makes these things seem extraordinary. What more ordinary experience, for example, than to meet a friend in some London street—perhaps one friend of the only dozen or so you have among the four millions of people about you? The odds against you two, of all the millions, choosing the one street of the thousands in London to walk down at the same minute of time, would seem incalculable; and yet the chance comes off so often as to be a matter of the most ordinary experience.

On this occasion I was expecting orders from my editor to produce certain articles on the subject of the London hospitals. It will be remembered that the matter was very much in the air a few years ago, and as nothing is professionally more uncomfortable than to be called on suddenly for an accurate and reasonable leading article on a subject one knows nothing about, I wrote to my friend, Barton McCarthy, who is house-surgeon at St. Augustine's, and he replied by an offer to tell me anything I cared to ask if I would call at the hospital.

I set out accordingly some little time after a breakfast even later than ordinary, and called in at Hewitt's office on my way downstairs, to say that I should not be lunching at our usual place that day.

"No," Hewitt answered, "nor shall I, I expect. I'm off to the City, at once. I have an urgent message to go immediately to Kingsley, Bell and Dalton's, in Broad Street, where a big bond robbery has just been discovered. Perhaps I can give you a lift in my cab?"

We hurried off together accordingly. Hewitt knew nothing of the case he had to examine, and so could tell me nothing, beyond the short urgent request that he would come at once, and that the matter involved the loss of bonds to a very large amount; and he dropped me at a convenient spot, whence my walk to the hospital was but a short one.

I saw my friend McCarthy, and bothered him very successfully for nearly an hour, getting all the information I had expected, and more, during a very interesting walk through the great hospital.

"You get some idea in a place like this," said McCarthy, as we came at last into the receiving room for accident cases, "you get some idea, Brett, of the size of this great London machine working about us. You might walk about the streets for a week and never see a serious accident, or even an accident at all, and yet, you see, here they come all day long—a stream of people damaged or killed in the machine."

A decent workman was having a gashed hand dressed and strapped, and a navvy with bandages about his head was being led away by a friend. Nurses and dressers were waiting ready to take their orderly turns at the incoming casualties, and as we looked a more serious case was brought in on an ambulance by two policemen. The patient was a ragged, disreputable-looking fellow of middle age, in grimy and tattered clothes, whose head had been roughly bandaged by the policemen who brought him. He had been knocked down and kicked on the head by a butcher's cart-horse, it seemed, in Moorgate Street, and he was quite insensible. A very short examination showed that the case was nothing trivial, and McCarthy sent me to sit in his private room to wait lunch, while he gave the matter his personal attention.

When he returned he brought a small crumpled envelope in his hand. "That case is put to bed," he said, "still insensible."

"Is it very bad?" I asked.

"Slight fracture of the occipital, and, of course, concussion of the brain—probably contusion, too, I expect we shall find presently. Not so over serious for a healthy man, but I'm afraid he's an old soaker—the sort that crumple up at a touch. Nobody knows him, and there's nothing to identify him in the pockets—a few coppers, an old knife, and so on. So we can't send to tell his friends—unless we bring in your friend Martin Hewitt to trace 'em out, which would come too expensive. Besides," McCarthy added, dropping into a seat before his desk, "if he's got any friends they'll come, sooner or later, when they miss him. This is the only thing he'd got beside what's in the pockets—he'd been sent on a message, probably."

My friend held up the crumpled envelope and took from it a small key. "He'd got this envelope gripped tightly in his hand," he said, "but there was no address on it, so we tore it open in the hope of finding one inside. But there was nothing there but the key. If you were a very promising pupil of your friend Hewitt, I should expect you to take a glance at it and tell us the man's address at once, together with his age, birthplace, when vaccinated, and the residence of his maternal grandmother. But you're not, so I'll let you off."

McCarthy turned the key idly about in his hand and tried it on a lock in his desk. "Stopped up," he remarked, withdrawing it, and peeping into the barrel; "not dirt, either—stopped up with paper! What's that for?"

He took a pin to clear the barrel, and the paper came away quite readily. It was a tight little roll, which the surgeon pulled out into a small strip rather less than three inches long and about half-an-inch broad.

"Hullo!" he exclaimed. "Look here! Here's a job for Martin Hewitt, after all! Figures! What does that mean? And what an amazing place to put them in! A key barrel! By Jove, Brett, this looks like one of your favourite adventures. Somebody sends a key in an envelope, and a row of incomprehensible figures rolled up inside the key. Look at it!"

I took the key and the paper. The key was of a good sort; small, inscribed "Tripp's Patent" on the bow, and it evidently belonged to a superior lever lock. The paper which had come from the barrel was very thin and tough—a kind I have seen used in typewriters. It had been very carefully and closely rolled, and then pushed into the key so that its natural tendency to open out held it tightly within. Written upon it with a fine pen appeared a series of very minute figures, thus:—

9, 8, 14, 4, 20, 18, 5, 9; 15, 19, 20, 0, 3, 9, 8, 5; 3, 23, 0, 0, 5, 13, 14, 19; 19, 20, 0, 0, 0, 0, 6, 1; 5, 20, 0, 0, 0, 0, 3, 22; 1, 15, 0, 0, 0, 0, 18, 5; 1, 8, 20, 11, 18, 9, 5, 20; 12, 5, 23, 14, 14, 1, 1, 20.

"Well," inquired McCarthy, "what do you make of it?"

"Not much as yet," I admitted. "But it's pretty certain it must be a cryptogram or code-writing of some sort; and if that's the case, I think I might back myself to read it—with a little time." For I well remembered the case of the "Flitterbat Lancers," and the lesson in cypher-reading which Hewitt then gave me.

"Come," my friend replied, much interested, "let's see how you do it. Meantime we'll get on with our lunch."

I took a pencil and a spare sheet of paper, and I studied those figures all through lunch and for some little time after. It soon became plain that the problem was much more difficult than it looked, and I said so. "At the first glance," I said, "it looked a fairly easy cypher; but as a matter of fact, I don't think it's easy at all. One assumes, of course, that the figures stand for letters, and on that assumption two or three peculiarities are noticeable. First, the highest number written here is 23, so that all the letters indicated, in whatever order they may come, are within the compass of the twenty-six letters of the alphabet. Next, the numbers most frequently repeated, if we except the noughts, are 5 and 20, which occur seven times each. Now, the vowel most frequently occurring in average English writing is e, and you will at once perceive that e is number five in the alphabet, counting from the beginning. More, if we go on counting so, we shall find that 20 is t, which is one of the most frequently occurring consonants. This would seem to hint that the cypher is of the very simplest description, consisting of the mere substitution of figures for letters in the exact order of the alphabet. But what, then, of the noughts? What can they mean? More especially when we consider that in three places there are actually four noughts in succession; for, of course, no letter is repeated four times successively in any English word, nor in any foreign word that I can imagine. But let us put down the letters in substitution for the figures, on the supposition that the figures stand for letters in their alphabetical order, leaving the noughts as they are. Then we get this."

I rapidly pencilled the letters on the spare paper, thus:—i, h, n, d, t, r, e, i; 0, s, t, 0, c, i, h, e; c, w, 0, 0, e, m, n, s; s, t, 0, 0, 0, 0, f, a; e, t, 0, 0, 0, 0, c, v; a, 0, 0, 0, 0, 0, r, e; a, h, t, k, r, i, e, t; l, e, w, n, n, a, a, t.

"See there," I said. "Now, I can make nothing of that. When I come to examine the comparative frequency of the different letters, I find them much as they might be expected to be in a sentence of normal English, and any change would destroy the proportion. E and t are the most frequent, and then come a, n, i, r, s, and c. But as they stand they all mean nothing. It is possible that this may be one of the difficult variable letter cyphers, which Hewitt might read, but I can't. But even then, if the values of the letters change as they would do, they would get out of their normal proportions of frequency; so that a variable letter cypher seems unlikely. And there is another oddity. Look, and you will see that, counting the noughts in, the letters go in groups of eight, with a semi-colon at the end of each group. Now, it is impossible that the message can be a sentence in which every word has exactly eight letters—or, at least, I should think so. It can scarcely be that the semi-colon itself means a letter—it would be singular for one letter to occur with such curious regularity as that. There is no other visible division between the words, nor any single one of the usual aids by which the reader of secret cypher is able to take a hold of his work. No, I'm afraid I must give it up; for the present, at any rate. But I really think it is a thing that would vastly interest Hewitt, if I might show it to him. I suppose I mustn't?"

"Well," McCarthy answered, "perhaps it isn't strictly according to rule, but I think I might venture to lend it to you till to-morrow, if that will do. Indeed, I think, on second thoughts, that I may consider myself quite justified, since it may lead to the man's identification, and it will be a sufficient answer to any inquiry to say that I have shown it to Mr. Martin Hewitt for that purpose. But you'll be careful of it, won't you? Do you want the key, too?"

"I think, if I may, I will take the key and the envelope all together. You can never tell what may or what may not help him, and the three things may hang together, and perhaps explain each other in some mysterious way."

"Very good—here's the whole bag of tricks. It's a queer business altogether, and I must say I feel inquisitive; certainly, if Hewitt can get anything out of those figures I shall be mighty curious to know how he does it. You'll come in again to-morrow, then?"

I promised I would, and walked off with the crumpled envelope, the little key, and the puzzling strip of figures. Since the lesson from Hewitt which I have alluded to, I had often amused myself with cryptogram reading, and I had never found a cypher message in a newspaper "agony-column" the meaning of which I could not get at with a little trouble. But this was something altogether beyond me; and if I have any reader who prides himself on his ability to read secret cypher, I recommend him to try his skill on this one before he reads further.

The circumstances, too, seemed as puzzling as the writing itself. Why, if any person wished to send a note and a key in a closed envelope, should he take the trouble to pack the note inside the key? Why, especially when the note was already written in so baffling a cypher? Whither had this ragged messenger been going with the mysterious package, and who had sent him, and why?

Guessing and musing, I reached home, and found that Hewitt had returned before me. I made my way into his office, and came on him sitting at his desk with a large lens, attentively examining a broken brass padlock.

"Am I bothering you?" I asked. "Are you on the bond robbery, now?"

Martin Hewitt nodded, with a jerk of the hand toward the padlock. "It's a tough job," he said, "and I shall shut myself up presently and think hard over it; just now I can't see my way into it at all. But what have you got there?"

"Never mind," I said, "you're too busy now. I came across something very odd at the hospital, which I thought would interest you—that's all."

"Very well, let me see it. I haven't begun my bout of cogitation yet. Show me."

I put the envelope, the key and the paper on the table before him. Hewitt, with a glance of surprise, picked up the key and examined it. "That's curious," he said, and straightway began fitting the key to the broken padlock on the desk.

"Why, man alive!" he cried, with a sudden burst of excitement, "where did you get this? This—this is the article—the key—the very thing I want!" He sprang to his feet and stared in my face in sheer amazement. "Heavens, Brett, the thing's almost supernatural! I've a broken lever padlock here, and of all things in the world I wanted to find the one key that fitted it; and you calmly walk in and clap down the very thing under my nose! Where did you get it?"

I told him the tale of the man who had been knocked down in Moorgate Street, and I explained exactly how the paper, the key and the envelope were found in relation to each other, and why I had brought them.

"And when was the man knocked over?" Hewitt asked.

"Some time between one and two o'clock, I should say," I replied. "They brought him in well before two, at any rate."

Hewitt stared into vacancy for a moment, thinking hard. Then he said, "Brett, I believe you've saved my reputation—not that it could have suffered much, perhaps, in such a desperate case. But as a fact I had already advised the calling in of the police, and should, perhaps, even have given up the part of the case still left me. But this ought to put me on the proper track. You see, every one of these patent lever locks differs in some slight degree from all the rest, and only its own key will fit it; and here, by this amazing piece of good luck, is the one key for this very lock, and the man who had it is detained in hospital. Come, I'm off to see him. Insensible, you say, when you left?"

"Yes," I answered, "and likely to be so for some time, McCarthy thinks; so you probably won't get much information out of him just yet. But the cypher——"

"I'll examine the cypher as I go along, I think. But I should like to take a look at the man, at any rate, even if he can't tell me anything. Will you give me a note to your friend McCarthy?"

"Of course," I answered, readily, and sat down to scribble the few lines necessary to introduce Hewitt.

When I had finished, Hewitt, who had been examining the cryptogram meanwhile, remarked: "This cypher is something out of the common, Brett. I certainly don't expect to be able to read it in the cab-journey—perhaps not in a week of study. The man who devised this is a man of abilities altogether beyond the average."

"I have had my best try at it," I said, "but it beats me wholly. I brought it purely as a matter of curiosity, to show you; it was the merest chance that I brought the key as well."

"And if you hadn't I should probably have put the cypher aside until the case was over, and so have missed the whole thing. Another lesson never to despise what seem like trifles. If you have studied the cypher you have no doubt observed—but there, we'll talk that over afterwards, and the whole case if you like. I'll go now, and I'll tell you all about the business when time permits."



II

Here is the case of the bond robbery as it had been presented to Martin Hewitt that morning, while I was at St. Augustine's Hospital, and as I learned it from him later. I had been a little puzzled to hear Hewitt say that the case had seemed so desperately hopeless that he advised the calling in of the police, because my experience had rather been that it was Hewitt who was commonly called in—often too late—when the police were beaten, and I had never before heard of a case in which this order of things was reversed. It turned out, however, as will be seen, that in the state of the matter as it first presented itself the only measures that seemed possible were such as it was in the power of the police alone to adopt.

Messrs. Kingsley, Bell, and Dalton were an old-established firm of brokers whose operations were not enormous nor much in the eye of the public, but who carried on a steady and reputable business in a set of offices high up in a great building in Broad Street—a building so large that the notice "Offices to let" was a permanent fixture in the front porch. The firm's clients were chiefly steady-going investors of the old-fashioned sort, who wished to avoid all speculative fireworks, and to deal through a firm whose habits were conformable to their own. The last Kingsley had left the firm and soon afterward died, some few years back, and now the head of the firm was Mr. Robert Stanstead Bell, a gentleman of some sixty years of age. There were a couple of sleeping partners—relations—but the one other active partner was Mr. Clarence Dalton, a young man but recently advanced to partnership, and, it was said, likely to become Mr. Bell's son-in-law whenever the old gentleman's daughter Lilian should be married.

The steady, even round of business to which Kingsley, Bell, and Dalton, and their clerks were accustomed was suddenly interrupted by an appalling loss. It was discovered that bonds were missing from the safe, bonds to the amount of some L25,000; and whence, how, or when they were taken was an utter mystery. It was this loss which had occasioned the urgent message to Hewitt.

When Hewitt reached the spot he was shown at once into an inner office, where Mr. Bell sat waiting. The old gentleman was in a sad state of agitation, and it was with some difficulty that Hewitt got from him a reasonably connected account of the trouble.

"The loss comes at such a time, Mr. Hewitt," the senior partner explained, "that I don't know but it may ruin us utterly, unless my clients' property can be recovered. We have had to pay out heavy sums of late to the representatives of dead or retiring partners, and other circumstances combine with these to make the matter in this way even more terribly serious than the very large amount of the loss would seem to suggest. So I beg you will do what you can."

"That of course," responded Hewitt. "But please tell me, as clearly as you can, the precise circumstances of the case. Where were the bonds taken from?"

"This safe," Mr. Bell answered, turning toward a very large and heavy one, which might almost have been called a small strong room. "They were kept, together with others, in this box, one of several, as you see. The box was fastened, like the rest, with a Tripp's patent lever padlock, the only key of which I kept, together with the key of the safe."

The box indicated was one of ordinary thin sheet iron, japanned black—something like what is called a deed box.

"The padlock has been broken open, I see," Hewitt observed.

"Yes, but I did that myself this morning. It had been blocked up in some way, so that the key wouldn't turn—doubtless in order to cause delay when next the box should come to be opened. As it was I might have desisted and put off opening it till later, but I had a reason for wishing to refer at once to a list which was in the box, and so I decided to break the padlock. It was more difficult than one might expect, with such a small padlock."

"And then you discovered your loss?"

"Then I discovered the loss, Mr. Hewitt, though it was a mere chance even then. For see! All the bonds have not been taken, and those left are placed on the top, while the space below is filled with dummies. I hardly know why I turned them over—for the list was at the top—but I did, and then——" Mr. Bell finished with a despairing gesture.

"And this was some time this morning?"

"At about half-past eleven."

"And when did you last open the box before that?"

"Ten days ago at least, I should think—and even then the bonds may have been gone, for I only opened it to refer to the same list, and I examined nothing else."

"You say that some bonds are left and others are gone. I presume those taken are such as would be easy to negotiate, and those left are such as would be difficult. Is that the fact?"

"Precisely."

"Then the thief evidently knows the ropes, and altogether the matter would seem awkward. For anything short of ten days, you see, and quite possibly for even a longer time than that, these bonds have been in the undisturbed possession of some person who could easily dispose of them, and would certainly do so without a moment's delay."

Mr. Bell nodded sadly. "Quite true," he said.

"But now tell me a little more. You say you yourself keep the only key of the padlock, as well as the key of the safe. So that you open the safe every morning yourself and close it at night?"

"Just so."

"And do you never entrust the keys to anybody else?"

"The key of the safe is on a separate bunch from the key of the box. This second bunch, with the key of the box, is always in my pocket, and not a soul else ever touches it. The other bunch, with the outer key of the safe, I sometimes hand to my partner, or to the head clerk, Mr. Foster, if something is wanted from the safe when I am busy. Though, as a rule, the safe door is open so long as I am about the place. Nothing but the books can be taken out without the use of other keys for the drawers and boxes, which I keep on the private bunch."

"And would it be possible for anybody—anybody at all, mind—to get at that private bunch of keys in such a way, for instance, as to be able to take a wax impression of the key of that bond-box?"

"No, certainly not," Mr. Bell answered with decision. "Certainly not. At any rate, not in this office," he added.

"Ah, not in this office. Anywhere else?"

"No, nor anywhere else, I should think," the other replied, though this time a little more thoughtfully. "There's only my own family at home and the servants and——"

"Anybody who has access to this room of the office?" Hewitt asked keenly.

Mr. Bell seemed a little startled.

"Why, no," he said, "nobody at home comes to the office—not even a visitor, except, of course, my junior partner, who visits the room pretty frequently."

"Very well. You don't remember ever mislaying the keys temporarily, I suppose, either here or at home?"

"No-o," Mr. Bell replied slowly. "I can't say that I do remember anything of the sort. No—and I believe I should be sure to remember if I had."

"Ah! And when you realised your loss what did you do? Told your partner first, I suppose?"

"No—he doesn't know of the discovery. He went out just before I made it, and I don't expect him in again to-day." But as Mr. Bell spoke there grew plain in his face the pallor of a new fear.

Martin Hewitt observed it, but kept his thoughts to himself. "Well," he said, "you didn't tell your partner. Nor the police?"

"No, Mr. Hewitt. You see, of course, the first thing the police attempt is to catch and punish the thief, and they make the recovery of the property a subsidiary object. But for me, Mr. Hewitt, the recovery of the property, as I have explained, is the one great consideration. Punish the thief by all means, but first save me from ruin, Mr. Hewitt! That is why I sent for you; for that, and because I thought it might be advisable to keep the matter quiet, till you had taken some steps."

"There is something in that consideration, certainly. So you have told nobody of the loss, except me?"

"Nobody but Foster, my head clerk—an old and faithful servant. It was he, in fact, who suggested sending for you. As he put it very forcibly, you can act for me and my interests, while the police act for themselves, and—very properly, of course, as police—in the interest of the community."

"Very well. I see you have several clerks in the outer office. Do they ever come into this room?"

"Never, unless they are sent for."

"If you and your partner were out, and one of the clerks came in without being sent for, the rest would know it, of course?"

"Certainly."

"I observe three private rooms opening out of this. What are they?"

"This is a sort of extra inner room where I have private interviews with clients—I was in there with a client for half an hour this morning before I discovered the loss. The next is a mere little box of a room where the correspondence clerk sits and works. The other is a larger place—it is shared between my partner, Mr. Clarence Dalton, and the head clerk, Mr. Foster."

"Now let me have your broken padlock—and the key. I see you have forced up the front plate with a screw-driver. I will borrow that screw-driver, if you please, and force it off completely."

Hewitt's client produced a screw-driver from a drawer, and in a very few moments the interior of the little padlock lay uncovered. Hewitt examined the lock attentively for some few minutes, trying the key several times against the levers. Then he stood up and said—

"Mr. Bell, you have made a mistake. This is not your lock at all!"

"Not my lock!" exclaimed the broker. "What do you mean? I tell you it is the lock of that box, and I broke it open myself!"

"Yes," answered Hewitt calmly, "it was on that box, and you broke it open yourself; but all the same it is not your lock. Let me explain. These are very good little padlocks, with an excellent lever action, 'dogged against detent,' as the technical phrase goes; so that only the key properly made for each lock will open it. They are so good, indeed, as locks, that it would be a waste of time to try picking them, when, because of their small size, it is so very easy to break them apart, just as you have done yourself, and just as I could probably have done in half the time, having had rather more experience. Now that is what has been done with your lock by the person who has your bonds. But of course a broken lock has one disadvantage as compared with a skilfully picked lock—it shows at the first glance what has happened. In this case, Mr. Bell, your lock has been broken and taken away, and the thief, having first provided himself with another padlock of precisely the same make and size, has substituted that, locked it with its proper key and so left it!"

"What! Then that was why——"

"That, of course, was why you supposed it to be out of order when you attempted to open it with your key. As a matter of fact, it is even now in perfectly good order, except for the damage we have jointly committed with the screw-driver. And now, observe! That lock was shut by another key; if the man that did that is as sharp as I suppose he is, he will have got rid of that key at once. But perhaps he hasn't; and if not, then the man who has that key is the thief. At any rate, the key is the clue we must hunt for. Let us have your clerks in one by one, and look at their keys. Some are out at lunch by this time, probably?"

"No—I said they might be wanted, so kept them. I thought you might prefer to see them before they went out."

"Very well thought of, but perhaps scarcely judicious, on the whole. Because if there is a guilty person among them it may give him a hint; and the odds are rather against its being very useful, considering the possibility—even probability—that the bonds and the collateral evidence left here days ago. But we'll look at their keys, by all means, and then they may go to lunch as soon as you please. Let me do the talking, or perhaps you'll start a scare. Send for the nearest clerks first, then the others. As each comes in, mention his name, so that I can hear it. Say, 'Oh, Mr. Brown'—or Jones, or what not—'have you some keys about you?' Don't mention my name, and I will do the rest. Push to the door of the safe, and lock this drawer in the table."

Mr. Bell did as Hewitt directed, and then called the head clerk, Mr. Foster, from his room, with the prescribed inquiry about keys.

"Yes, Mr. Foster," Hewitt added pleasantly, "I'm not sure that the lock is quite in order, but I promised to open it for Mr. Bell, so we'll try."

Mr. Foster, a slim, active old gentleman, grown grey in the firm's service, pulled a bunch of keys from his pocket, and Hewitt scrutinised each narrowly. "No," he said, "I'm afraid none of these will do. Stay," he added suddenly, and turning his back, carried the bunch to the window. "No," he concluded, as he came back to the table and tried one of the keys fruitlessly. "No, I'm afraid none of those will do. Thank you, Mr. Foster. You don't happen to have any more, do you?"

No, Mr. Foster hadn't any more, and he retired to his room. Then Mr. Bell called the correspondence clerk, Mr. Henning. Mr. Henning was a much younger man than the head clerk—twenty-six or so—pale and blue-eyed, with weak whiskers and a straggling moustache. His keys were just as readily produced as Mr. Foster's, but again Hewitt's examination was unsuccessful. The only other key he had belonged to the typewriter, and that did not fit.

Then came Mr. Potter, the book-keeper, round, and tubby, and puffy, and his keys went under inspection in the same way, taking a little longer this time, with two separate dashes to the light of the window. Then there was Mr. Robson, young and spruce, Mr. Clancy, older and less tidy, and four or five more. All the keys were examined, all with the same lack of success, and all the clerks were sent away to take their turns at lunch.

"No," Hewitt reported, as soon as he and Mr. Bell were alone again, "it was certainly none of those keys. Though indeed, my little attempt was desperate at best. A man would be a fool to keep that key longer than he needed it, and especially to string it with his others. Still, of course, it is by just such blunders as that that nine criminals out of ten are discovered. And now let me take a good look at that box and its contents."

He lifted the box from the safe to the table, and narrowly scrutinised its exterior, especially about the hasp, where the padlock had been. "Either the thief was an experienced hand," he said, "or he took some steady practice with a few such padlocks as this before setting to work. There are no signs of banging about or slipping of tools anywhere."

"But, of course, banging or anything violent would have been noticed in a place like this," Mr. Bell remarked.

"In office hours, yes," responded Hewitt. "But we mustn't forget that office hours are only seven or eight out of the twenty-four."

"But you don't suspect burglary, do you?"

"I'm afraid, as yet, I've precious little ground for suspecting anything definite," Hewitt answered; "but we must keep awake to every possibility. Now let us see the dummies." He turned them over, and loosened them wherever they were tied. "Yes," he remarked, "quite neatly done. Filled in with ordinary blank foolscap, such as, no doubt, you have in your office—but, then, it is in every other office, too; every stationer has it by the ream. No marks anywhere—no old newspapers, nothing that could give the shadow of a clue." He dropped the last of the papers, and turned to his client. "Mr. Bell," he said, "this thing has been thought out to the last inch. There is something like genius in this robbery—if genius is the capacity for taking pains. My advice to you is to call in the Scotland Yard people at once."

"Do you mean you can do nothing?" asked Mr. Bell despairingly. "Don't tell me that, Mr. Hewitt!"

"No, I don't mean that," Hewitt answered. "I mean that until I have had time to think the thing over very thoroughly I can't tell what I can or ought to do. Meantime, I think the police should know; not because I think they can see farther into the thing than I can—for, indeed, I don't think they can; but simply because the thief is getting a longer start every moment, and the police are armed with powers that are not at my disposal. They can get search warrants, stop people at ports and railway stations, arrest suspects—do a score of things that will be necessary. Send to Scotland Yard and get Detective Inspector Plummer, if he's available—he's as good a man as they have. Tell him that you've engaged me, or, better still, write a note to the Scotland Yard authorities, and let me have it, to send or not as I think best, after I have turned the thing over in my mind. I shall take one good look round this office, and then run back to my rooms for an hour or two's hard consideration of whatever I may see. One or two small things I have seen already—though I'd rather not mention them till I've made up my mind how they bear. Matters seem likely to have gone so far that perhaps the regular police course of catching the thief first will be the best plan, if it can be done. Meantime, it will be my business to keep my eye first on the recovery of the bonds. But I think we must have the police, Mr. Bell. Now, I'll take my general look round."



III

After Martin Hewitt had rushed off to St. Augustine's Hospital with the key, the envelope, and the cypher I had brought him, I heard nothing of him till dusk fell—about six. Then I received this telegram:—

/# "Cypher read. Most interesting case. If you can spare an hour be outside 120 Broad Street at six thirty.—Hewitt." #/

I had to be at my office between eight and nine, and to keep Hewitt's appointment I should probably have to sacrifice my dinner. But I was particularly curious to know the meaning of that cypher, and just as curious to know how it could be read; and, moreover, I knew that any case that Hewitt called interesting would probably be interesting above the common. So I took my hat and sought a cab.

I was first at the meeting-place—indeed, a little before my time. No. 120 Broad Street was a great new building of offices, most, if not all, closed at this time—a fact indicated by the shutting of one of the halves of the big front door, where a char-woman was sweeping the steps under the board which announced that offices were to be let. I waited nearly a quarter of an hour, and then at last a hansom stopped and deposited Hewitt and another older gentleman before me.

"Hope we haven't kept you waiting, Brett," Hewitt said. "This is Mr. Bell, of Kingsley, Bell and Dalton; it took me a little longer than I expected to reach him. His offices are shut, and the clerks all gone, but we are going to turn up the lights for a bit. The lift man is gone too, I expect, so we shall have a good long stair-climb."

As to the lift man Hewitt was right, and during our long climb I received, briefly, an account of the loss Mr. Bell's firm had suffered. "I have told Mr. Bell," Hewitt said, "that it was you who happened across the key in such an odd fashion, and when I wired I was sure he would be glad to let you see the upshot of your strange bit of luck. I was also pretty sure that you would like to see it, too. For I really believe that this case—which I confess seemed pretty near hopeless a few hours ago—is coming to an issue now, and here."

"Did you get any information out of the man in the hospital?" I asked.

"Not a scrap," Hewitt replied. "He was still insensible, and though I saw his clothes, and they told me a good deal about the gentleman's personal habits—which are not dazzlingly noble, to put it mildly—they told me nothing else whatever, except that he had recently been knocked down in the mud, which I knew already. But the cypher has told me something, as I will explain presently."

By this time we had reached the high floor in which the offices stood, and Mr. Bell, all wonder and pale agitation, unlocked the outer door, and turned on the electric light.

"Now," cried Hewitt, "show me your ventilators!"

There were some, it seemed, in the top panes of the windows, but these were not what Hewitt wanted. There were others in the form of upright chambers or flues, made of metal, and painted the same colour as the walls about them. They rose from the floor in corners and wall angles, and could be shut or opened by means of lids over their upper ends. These were more to Hewitt's mind, and he went about from one to another, groping under the lids, and poking down into the flues with a walking-stick. There was a wire-grating, or diaphragm, it seemed, in each of them, two or three feet down, and we could hear the end of the stick raking on this at each investigation. One after another of these ventilators Hewitt examined, till he had examined them all, in outer and inner rooms, without result; and I could see that he was disappointed.

"There must be another somewhere," he said, and hunted afresh.

But plainly he had tried them all, and now he could do no more than try them all again, with as little result.

"It is a ventilator," he said, positively. "Unless——" he broke off thoughtfully and stood silent for a few moments. "Ah! of course!" he resumed presently. "We'll send for the housekeeper and a candle. Which is the nearest empty office—the nearest office to let? Is there one on this floor?"

"I think not," Mr. Bell answered. "But there's one on the floor below, just opposite the lift—I see the bill on the door every day as I come up."

"We'll try that, then. I'll rake out every ventilator in this palatial edifice before I'll call myself beaten. Come, call the housekeeper. Is there a speaking tube? Tell him to bring a light."

The housekeeper came, wonderingly, with a watch-man's oil-lantern, and we all went to the floor below. Opposite the lift was a glass door from which a bill had recently been torn.

"Why, it's let!" said Mr. Bell.

"Yes, sir," assented the housekeeper. "Let a day or two ago to a Mr. Catherton Hunt. Or, at least, a deposit was paid."

"But see—the door's not locked," Hewitt observed, pushing it open. "I think we'll trespass on Mr. Catherton Hunt's new offices, since they seem quite empty, and he hasn't taken possession. Come—ventilators!"

It was a small office—an outer room of moderate size, and one smaller inner room. Hewitt at once attacked the ventilators in the larger apartment—there were two of them—but retired disappointed from each. There was one ventilator only in the small room. Hewitt tilted the lid, which was at about the level of his eyes, thrust in his hand, and drew forth a bundle of folded papers; thrust in his hand again and drew forth another bundle; did it again, and drew forth more!

Mr. Bell fell upon the first bundle almost as a dog falls upon a bone; and now he snatched eagerly at each successive paper or bundle, till Hewitt raked the grating with his stick, and declared that there were no more. "Is that all?" he asked.

Mr. Bell went tremblingly from paper to paper, and, at last, said that he believed it really was. "I can verify it by the list upstairs," he added, "if you are sure there are no more."

"No more," repeated Hewitt, rattling his stick in the ventilator again. "Let us go and verify, by all means."

We sent the puzzled housekeeper away, and returned to the office above, and presently Mr. Bell, now beginning so far to recover from his amazement as to express incoherent gratitude, reported that the bonds were correct and complete to the last and least.

"Very well," said Hewitt, "then my part of the business is done, though I must say I've had luck, or rather, Brett has had it for me. But the police must come on now. I think, Mr. Bell, we'll go along to Scotland Yard when we leave here. They'll be wanting to see Mr. Catherton Hunt, I expect, whoever he is—and somebody in your office, too, if I'm not sadly mistaken."

"Who?" gasped Mr. Bell.

"That, perhaps, you can help to point out. See here—do you know whose figures they are?" and Hewitt produced the small slip of paper containing the cypher.

"They're very small," remarked Mr. Bell, putting on his glasses; "very small indeed; but I think—why they're Henning's, I do believe!"

"Ah! one or two other little things seemed to point that way. Henning is your correspondence clerk, I believe, and I expect this thin little slip is a specimen of your typewriter paper. Have you any of his written figures for comparison?"

"Well no—I hardly think—you see he typewrites his letters, and although I know his writing very well I can't at the moment put my hand on any figures of his."

"Never mind—it's mere matter of curiosity; the police will ask him questions in the morning. What I believe has happened is this. Our friend Henning—if he's the man—has a friend outside a great deal cleverer than himself—though he would seem to have his share of cunning, too. Between them they resolved to rob you in the way they have done—temporarily. Henning was to take advantage of his position in that little inner room to get at the safe some day when it was open and when you were engaged in your own private inner room with a client, so leaving the safe unwatched. He was provided with a spare patent padlock and key, of the sort you used on that black box, and his confederate had drilled him in the trick of breaking that particular sort of padlock open, with other spare specimens. He got his opportunity this morning."

"Only this morning?"

"This morning, I think, else we should never have got these bonds back, nor even have heard of them again. I think you said you were engaged with a client for half an hour?"

"Yes, from about half-past ten to eleven."

"That was his chance, and he took it. He broke the padlock, took out the bonds, substituted the dummies he had already prepared in his own desk, and locked the box again with the new padlock. Meantime Hunt had paid a deposit, pending references, on the office below—the nearest empty room. Of course, he wouldn't get the key until the tenancy was finally accepted—which he never intended it should be. But he easily arranged to have the door left unlocked for a day or two, on some convenient excuse—arranging decorations, or what not. And the bill was taken down, so that prospective and prospecting tenants were kept away. The bonds being stolen, Henning took the first opportunity of carrying them to the empty office—probably piecemeal—a thing he could easily manage almost under your nose, before you were aware of your loss. There he was to conceal them, either in the chimney, under the boards, or in the ventilator, as he might find convenient—and he found the ventilator most convenient. Then he was to apprise his confederate of the fact that the robbery had been effected in order that Hunt might come and quietly fetch the plunder away. The message was to take an ingenious form. Hunt was to have a fellow waiting about in the street, and as soon as Henning could get out—say to lunch—he was just to send the key by this messenger—the key with which he had locked the new padlock on the black box. You see the advantages of that simple arrangement. First, the key, which is evidence, is got rid of in a safe and effectual way—a thing that couldn't be done as well by merely flinging it away on or near the premises, where it might be found. Next, the message is perfectly secret—the messenger could never guess what the key meant, nor could any other person not in the confederate's confidence. And, at the same time, the key tells all that is necessary; the robbery has been effected—come and remove the plunder.

"But something unforeseen happens. No sooner are the bonds stolen and safely hidden than you go to the box, find something wrong with the lock, break it open and discover the loss. This was a thing that they trusted would not happen till after the bonds were safely got away. More, I am sent for, the clerks are kept in from lunch, and so on. Henning gets into a funk, and resolves to send a message of special urgency to his confederate. For that purpose he uses a cypher which the two have agreed upon—the most ingenious cypher I have ever seen used for the purpose. He doesn't wish to make his message any more conspicuous than he need, so he writes his cypher on this scrap of paper and rolls it inside the key—probably another expedient agreed upon in case of necessity. Then the key goes into an envelope, for greater security of the cypher message, and the messenger gets it when Henning is at last released for lunch. What happened to the message we know; and here it is.

"Now I will not weary you with a detailed account of the different ways in which I attacked this cypher, but I will take the shortest possible cut to the true interpretation. A very short examination of the cryptogram shows that while no number is included above 23, the numbers, in their relative frequency, roughly agree with the relative frequency of the corresponding letters of the alphabet, a for 1, b for 2, and so on."

Here I handed Hewitt the pencilled note I had made at the hospital, with letters substituted for the figures, thus:—i, h, n, d, t, r, e, i; 0, s, t, 0, c, i, h, e; c, w, 0, 0, e, m, n, s; s, t, 0, 0, 0, 0, f, a; e, t, 0, 0, 0, 0, c, v; a, o, 0, 0, 0, 0, r, e; a, h, t, k, r, i, e, t; l, e, w, n, n, a, a, t.

Hewitt took the paper and went on. "If that were all the thing would be childishly simple. But you will see that we seem as far from the solution as ever; for the letters as they stand mean nothing, though in fact they are in normal relative frequency; so that if they mean other letters, all the rules are upset, and we are at a standstill. I admit that for a long time the thing bothered me. But a peculiarity struck me. Not only were the figures, or letters, disposed in groups of eight, but there were also eight such groups—sixty-four altogether. What did that suggest? What but a chessboard?"

"A chessboard?" I queried.

"Just so—a chessboard. Eight squares each way—sixty-four altogether. So I drew a rough representation of a chessboard, and set out the letters on it, in their order, like this:—

i h n d t r e i o s t o c i h e c w o o e m n s s t o o o o f a e t o o o o c v a o o o o o r e a h t k r i e t l e w n n a a t

"Now, there was my chessboard with my letters on it. I tried reading them downward, across, upward and diagonally, in the direction of the moves of different chess pieces—king, queen, rook and bishop. Nothing came of that, whatever I did; the thing was as unreadable as ever. But there remained one chess-move to try—the eccentric move of the knight; the move of one square forward, backward or sideways, and then one square diagonally, or, as it has sometimes been more concisely expressed, the move to the next square but one of a different colour from that on which it rests. I tried the knight's move, and I read the cypher.

"I began at the top left-hand corner, just as one does in reading a book. I read the moves downward—i to w, e and h, and found that led to nothing. So I took the one alternative move, and, with a little consideration, skipped along from i to t in the second line of squares, t in the top line, h in the second line, e in the third, r in the top and e in the second. That gave me an idea. There were the letters i, t, t, followed by the word here. I tried back from the i again, and taking in the reverse order the w, e and h which I had first given up, I read my own name, as you can see it, from the h on the bottom line but one, moving upward. So I had the words Hewitt here. I need not carry you through all the steps, which will now be plain enough to you. But I found that the message actually began in the right-hand corner, and read thus, the noughts counting for nothing—

"'Invent loss disc take at once Martin Hewitt here fear watch.'

"The noughts were plainly merely inserted to fill in unneeded squares, and keep the rest of the figures in their proper relative places when the cypher was written in line. At first I was a little puzzled to understand what seemed to be the first word invent. But it was quite clear that loss disc meant 'loss discovered,' so I concluded that here in the beginning was a contraction also, and that in was a separate word. In that case vent could be a contraction for no other word but 'ventilator,' in accordance with the sense of the words. So I concluded that the meaning of the whole sentence was simply this: 'The plunder is in the ventilator, the loss is discovered, take away the booty at once; Martin Hewitt is here, and I fear I may be watched.' There is the reading, and our little adventure this evening is what it has led to.