When the door of Corbett’s or Mensmore’s flat swung open before the skilful application of a skeleton key, a gust of cold air swept from the interior blackness, and whirled an accumulation of dust down the stairs.

It is curious how a disused house seems to bottle up, as it were, an atmospheric accumulation which always seeks to escape at the first available moment. Emptiness is more than a mere word; it has life and the power of growth. A residence closed for a week is less depressing than if it has not been inhabited for a month. If the period of neglect be lengthened into a year, the sense of dreariness is magnified immeasurably.

In this instance, the mysterious abode might have been the abiding-place of disembodied spirits, so cold was its aspect, so uninviting the dim vista that sprung into uncertain vision under the flickering rays of a wax vesta struck by the detectives.

But neither the policeman nor his companion was a nervous subject.

They entered at once, closed the door by its latch, and, aided by other matches, found the switch of the electric light.

In this brighter radiance the indefinable vanished. The flat became a cosy, fairly well appointed bachelor’s “diggings,” neglected and untidy, yet not without a semblance of comfort, which only needed the presence of a sturdy housemaid and a fire to be converted into the ordinary chambers with which the locality abounds.

Their first care was to draw down all the blinds, the neglect of which housewifely proceeding argued the careless departure of a mere male when the place was vacated.

A rapid preliminary survey followed, and drew from Bruce the remark:

“Furnished by a woman, but occupied by a man.”

Mr. White agreed, but he didn’t know why, so he put a tentative question on the point.

“Don’t you see,” said Bruce, “that the carpets match the upholstery of the furniture, that the beds have valances, that the spare bedroom for a guest is even more elaborate than that used by the tenant, that care has been taken in fitting up the kitchen, and taste displayed in the selection of pieces of bric-a-brac? Only a woman attends to these things. On the other hand, a card tray has been used as a receptacle for a cigar ash, the pictures—no woman ever buys a picture—have been picked up promiscuously from shops where they sell sporting prints, and the sides of the mantelpieces are chipped by having feet propped against them. There are plenty of other signs, but these suffice.”

Thenceforth the two men devoted themselves to their task, each after his kind.

The representative of Scotland Yard hunted for documents, photographs, torn envelopes; he looked at the covers of books to see if they were inscribed; he opened every drawer, ransacked every corner, peered into the interior of jars, pots, and ovens; appraised the value of furniture, noted its age, and was specially zealous in studying the appearance of the only bedroom which had been occupied so far as he could judge.

Bruce, having given a casual glance around, entered the sitting-room, selected the most comfortable chair, and proceeded to envelope himself in smoke.

He had not spent two minutes in Mensmore’s flat before he made a striking discovery.

The dwelling consisted of a central passage, dividing two equal portions from the other. That on the right contained a drawing-room and a large bedroom, with dressing-room attached. On the left were another bedroom, a dining-room, a kitchen, and a store-room. At the end of the passage, which terminated in the transverse corridor, were the bathroom, a pantry, and a small room, empty now, but apparently designed for a servant’s bedroom.

The furniture, as has been stated, was good in quality and sufficient for its purposes. But the fact which immediately impressed this skilled observer was that the arrangement of the sitting-room differed essentially from the other details of the flat.

The same care had not been taken in the disposition of the articles. They had been dumped down anyhow, without taste or regard for suitable position. The carpet had not been bought for this special apartment like the carpets elsewhere. A handsome ebony cabinet stood in the wrong place. The blue china ornaments obviously intended to fill its shelves were littered about the mantelpiece or on small tables, while the Satsuma ware meant for the over-mantel was stiffly disposed on the cabinet.

Small matters these, but Bruce thought them more fruitful of accurate theory than the detective’s hunt for a written history of the crime!

So, as he smoked, he mused and examined.

“The drawing-room was the last place to be furnished,” he thought. “The usual course. It remained empty for some time probably. The rest of the flat was arranged by a woman—Mrs. Hillmer in all likelihood—before the arrival of her brother. Then he came and tackled the vacant room. The history of the place is as plain as though I were present. More than that, a woman—Mrs. Hillmer again, let us say—fixed upon these latter purchases, but without measurements. She did not personally see to their adaptability, and she certainly did not supervise their final arrangement. Now, why was that? Again, these things are more worn than those in the other rooms. Were they bought second-hand? If so, why? A woman thinks most of her drawing-room. It is the last place in which she would economize.”

Mr. White entered, anxious and puzzled.

“Found anything?” inquired Claude, without looking at him.

“Not a rag, not a piece of old newspaper with a date on it. A lot of papers were burned in the kitchen grate, but from the remnants I judge that they were mostly bills.”

“The place has been systematically cleared, eh?”

“It looks like it.”

“Going to hunt here?”

“Yes. You don’t seem to take much interest in the premises, Mr. Bruce, though you persuaded me to do a bit of house-breaking in order to get here.”

“I find the quietude good for thought, Mr. White. Be good enough not to make more noise than is absolutely necessary.”

The other sniffed. He was disappointed. He hoped for something tangible from this visit, and the outlook was far from promising.

“This room appears to have been lived in a good deal,” he growled.

“That is one way of looking at it.”

“Is there any other way?” His voice snapped out the question as if he held the barrister personally responsible for his failure to gain a clue.

“No, Mr. White, I should have guessed your point of view exactly.”

“My point of view, indeed! Do you want me to draw up another chair and light a pipe? Should we be enlightened by tobacco smoke?”

“I cannot trust your tobacco. Try a cigar.”

The detective angrily thumped a Chesterfield lounge to see if it betrayed aught suspicious.

At that instant Bruce’s glance rested on the fireplace. The grate contained the ashes of a fire,—a fire not long lighted. This, combined with the undrawn blinds, argued a departure early in the morning.

“He went to Monte Carlo by the day Channel service,” mused Bruce. “He may have departed a few hours after Lady Dyke’s death, as Mrs. Hillmer was not certain as to the exact date.”

Somehow the few cinders attracted him. They had, perchance, witnessed a tragedy.

Suddenly he stopped smoking. He was so startled by something he had seen that the policeman must have noticed his agitation were not the detective at that instant intently screwing his eyes to peer behind the back of the elaborate cabinet.

On the hearth was a handsome Venetian fender. Into each end was loosely socketed a beautifully moulded piece of ironwork to hold the fire-irons. That on the left was whole, but from that on the right a small spike had been broken off.

By comparison with its fellow the missing portion was identical with the bit of iron found imbedded in the skull of the murdered woman. Of this damning fact Bruce had no manner of doubt, though the incriminatory article itself was then locked in a drawer in his own residence.

He did not move. He sat as one transfixed.

What a weapon for such a deed! Was ever more outlandish instrument used with murderous intent? The entire bracket could easily be detached from the fender, and would, no doubt, inflict a terrible blow. But why seize this clumsy device when it actually supported a heavy brass poker?

The thing savored of madness, of the wild vagary of a homicidal maniac. It was incomprehensible, strange beyond belief.

Yet as Bruce pictured the final scene in that tragedy, as he saw the ill-fated lady stagger helplessly to the ground before a treacherous and crushing stroke, a fierce light leaped into his face, and his lips set tight with unflinching purpose.

Had Mensmore been within reach at that moment he would assuredly have been lodged in a felon’s cell forthwith. No excuse, no palliation, would be accepted. The man who could so foully slay a gentle, kindly, high-minded woman deserved the utmost rigor of the law, no matter what the circumstances that led to the commission of the crime.

It was not often that Bruce allowed impulse to master reason so utterly.

In strange altruistic mood he asked himself why he did not spring from his chair, and, tearing the bracket from its supports, exhibit it to his fellow-worker, while he gave, in a few passionate sentences, the information that would set the French police to scour the Mediterranean littoral until they found the White Heather. Of what matter to him was the suffering of a sister or sweetheart? Did the man who killed Lady Dyke reck of these things? Yes, he would do it—

But a cry of triumph from the detective arrested the fateful words even as they trembled on his lips. “Here’s a find!” was the shout. “Thinking is all very well, Mr. Bruce, but hard work is better. What do you make of that?”

“That” was a letter, which, in the manner known to many a puzzled householder, had slipped down behind a drawer in the cabinet, to be crushed against the wardrobe at the back, and lie there forgotten and unnoticed.

Even in his perturbed state the barrister could not help glancing at the crumpled document, first noting the date, October 15th of the year just closed, with the superscription, “Mountain Butts, Wyoming.” There was no envelope.

It was addressed to “Dear Bertie,” and ran as follows:

“What do you think of that?” cried the detective, when Bruce had slowly mastered the contents of the letter.

“Think! I am too dazed to think.”

“We can now learn all about him from America.”

“About whom?”

“About Corbett, of course.”

“Then did Corbett travel by the same mail as this letter in order to murder Lady Dyke? It is dated October 15th, and she was killed November 6th. It takes twelve days, at the quickest, for a letter to come here from Wyoming. And Corbett, the writer of it, not the receiver, must have travelled in the same steamer, or its immediate successor.”

Mr. White’s face fell, but he stuck to his point:

“Anyhow, Corbett was here about that time. I have seen the secretary to the company that owns these flats. Corbett took the rooms for six months from September first. When asked for references he gave his sister’s name, and as she banks with the National—and she has always paid her rent for five years—it was good enough. Still, I must confess that Corbett could hardly be in Wyoming in October if he lived here in September and in November.”

The barrister answered between his set teeth: “Yes, it is rather puzzling.”

“Perhaps the letter was left there as a plant.”

“An elaborate one. It must have been conceived a month before the murder.”

“But suppose it never came from Wyoming. We have no proof that it was written in America.”

“We have proof of nothing at present.”

“Well, Mr. Bruce, have you a theory? This is the place where you ought to shine, you know.”

“I have no theory. I must think for hours, for days, before I see my way clear.”

“Clear to what, sir.”

“To telling you how, when, and where to arrest the murderer of Lady Dyke.”

“So this find of mine is of great importance?”

“Undoubtedly. I remember its contents sufficiently, but you will let me see it again if necessary?”

“With pleasure, sir. And that reminds me. You never returned that small bit of iron to me. You recollect I lent it to you some time since.”

“Perfectly. Come with me. I will model it in wax and give it to you.”

“All right, sir; but as we are here I may as well continue my search. I may drop on something else of value.”

Bruce resumed his seat, and did not stir until the detective had completely rummaged the cabinet. The reading of that queer epistle from Corbett to “Bertie”—from the real Simon Pure to the sham one—from one man to his double—had stopped him at the very threshold of disclosure.

The document impressed him as being genuine. If so, who on earth was Corbett, and why had Mensmore taken his name, if that was the solution of the tangle?

Whatever the explanation, he would not jump to a conclusion. The web had closed too securely round Mensmore to allow of escape. Hence, Bruce could bide his time. Another week might solve many elements in the case now indistinct and nebulous. He would wait.

The detective finally satisfied himself there was nothing else in the cabinet. He approached the fireplace, peered into every vase on the over-mantel, picked with his penknife at the back of the frame to feel for other letters, and in doing so several times kicked the fender.

The barrister vaguely wondered whether the man of method would note the missing portion of the iron “dog.”

“Surely,” he thought, “he will see it now,” as Mr. White bent to examine the ashes, and actually took the poker from the very support itself in order to rake among the cinders.

The other even scrutinized the fire-irons, but the too obvious fact that, so to speak, stared him in the face, escaped notice. He was quite wrapped up in his theory that Lady Dyke had been killed at Putney, and not in Sloane Square.

At last he quitted the room, and walked off to the small apartments at the end of the main corridor.

Instantly Bruce sprang forward, fell on his knees, and intently examined the iron rest with a strong lens. It bore no unusual signs in the locality of the break. Taking some wax from his pocket, he took a slight impression of the fracture.

When Mr. White returned, he found the barrister sitting in his chair, still smoking, and with set face and fixed eyes.

Soon afterwards they quitted the flat, carefully leaving all things as they found them. They said little on their way to Victoria Street, for Bruce was trying to explain Mensmore’s attitude at Monte Carlo, and the detective was considering the best use to which he could put that all-important letter.

Besides, Mr. White attributed his companion’s silence to annoyance. Had not he, White, laid hands on the only direct piece of evidence yet discovered as to Corbett’s identity, and this in defiance of Bruce’s spoken philosophy? He could afford to be generous and not to worry his amateur colleague with questions.

Thus they reached the barrister’s chambers. Bruce asked the other to sit down for a moment while he obtained a model of the small lump of iron. He took it into his bedroom, fitted in into the wax impression obtained at Raleigh Mansions, and noted that the two coincided perfectly.

He handed the bit of iron to White without comment.

The latter said: “It had better remain in my keeping now, sir, but if you want to see it again, of course I will be glad—”

“I shall never want it again,” said Bruce, and his voice was harsh and cold, for he had seldom experienced such a strain as the last hours had given him. “It is an accursed thing. It has caused one death already, and may cause others.”

“I sincerely hope it will cause a man to be hanged,” cried the detective, “for this affair is the warmest I have ever tackled. However, I’ll get him, as sure as his name’s Corbett, if he has forty aliases and as many addresses.”

Smith let Mr. White out. The latter, halting for a moment at the door, said quietly, “Is your name Corbett?”

“No, it ain’t, any more than yours is Black. See?”

Each man thought he had had his joke, so they were better friends thenceforth, but Mr. White was thoughtful as he passed into the street.

“This is a funny business,” he communed. “There isn’t enough evidence against Corbett to hang a cat, yet I think he’s the man. And Bruce is a queer chap. Was he cut up about me finding the letter, or has he got some notion in his head. He’s as close as an oyster. I wonder if he did dine at Hampstead on the evening of the murder, as he said at the inquest? I must inquire into it.”

CHAPTER XV