But it was days before he could trust himself so far. Meanwhile their acquaintance ripened, though with no very satisfactory results. The detective found himself led into telling stories of his early home-life to keep pace with the man who always had something of moment and solid interest to impart. This was undesirable, for instead of calling out a corresponding confidence from Brotherson, it only seemed to make his conversation more coldly impersonal.

In consequence, Sweet.w.a.ter suddenly found himself quite well and one evening, when he was sure that his neighbour was at home, he slid softly into his closet and laid his ear to the opening he had made there. The result was unexpected. Mr. Brotherson was pacing the floor, and talking softly to himself.

At first, the cadence and full music of the tones conveyed nothing to our far from literary detective. The victim of his secret machinations was expressing himself in words, words;--that was the point which counted with him. But as he listened longer and gradually took in the sense of these words, his heart went down lower and lower till it reached his boots. His inscrutable and ever disappointing neighbour was not indulging in self-communings of any kind. He was reciting poetry, and what was worse, poetry which he only half remembered and was trying to recall;--an incredible occupation for a man weighted with a criminal secret.

Sweet.w.a.ter was disgusted, and was withdrawing in high indignation from his vantage-point when something occurred of a startling enough nature to hold him where he was in almost breathless expectation.

The hole which in the darkness of the closet was always faintly visible, even when the light was not very strong in the adjoining room, had suddenly become a bright and shining loop-hole, with a suggestion of movement in the s.p.a.ce beyond. The book which had hid this hole on Brotherson's side had been taken down--the one book in all those hundreds whose removal threatened Sweet.w.a.ter's schemes, if not himself.

For an instant the thwarted detective listened for the angry shout or the smothered oath which would naturally follow the discovery by Brotherson of this attempted interference with his privacy.

But all was still on his side of the wall. A rustling of leaves could be heard, as the inventor searched for the poem he wanted, but nothing more. In withdrawing the book, he had failed to notice the hole in the plaster back of it. But he could hardly fail to see it when he came to put the book back. Meantime, suspense for Sweet.w.a.ter.

It was several minutes before he heard Mr. Brotherson's voice again, then it was in triumphant repet.i.tion of the lines which had escaped his memory. They were great words surely and Sweet.w.a.ter never forgot them, but the impression which they made upon his mind, an impression so forcible that he was able to repeat them, months afterward to Mr. Gryce, did not prevent him from noting the tone in which they were uttered, nor the thud which followed as the book was thrown down upon the floor.

"Fool!" The word rang out in bitter irony from his irate neighbour's lips. "What does he know of woman! Woman! Let him court a rich one and see--but that's all over and done with. No more harping on that string, and no more reading of poetry. I'll never,--" The rest was lost in his throat and was quite unintelligible to the anxious listener.

Self-revealing words, which an instant before would have aroused Sweet.w.a.ter's deepest interest! But they had suddenly lost all force for the unhappy listener. The sight of that hole still shining brightly before his eyes had distracted his thoughts and roused his liveliest apprehensions. If that book should be allowed to lie where it had fallen, then he was in for a period of uncertainty he shrank from contemplating. Any moment his neighbour might look up and catch sight of this hole bored in the backing of the shelves before him. Could the man who had been guilty of submitting him to this outrage stand the strain of waiting indefinitely for the moment of discovery? He doubted it, if the suspense lasted too long.

Shifting his position, he placed his eye where his ear had been. He could see very little. The s.p.a.ce before him, limited as it was to the width of the one volume withdrawn, precluded his seeing aught but what lay directly before him. Happily, it was in this narrow line of vision that Mr. Brotherson stood. He had resumed work upon his model and was so placed that while his face was not visible, his hands were, and as Sweet.w.a.ter watched these hands and noticed the delicacy of their manipulation, he was enough of a workman to realise that work so fine called for an undivided attention. He need not fear the gaze shifting, while those hands moved as warily as they did now.

Relieved for the moment, he left his post and, sitting down on the edge of his cot, gave himself up to thought.

He deserved this mischance. Had he profited properly by Mr. Gryce's teachings, he would not have been caught like this; he would have calculated not upon the nine hundred and ninety-nine chances of that book being left alone, but upon the thousandth one of its being the very one to be singled out and removed. Had he done this,--had he taken pains to so roughen and discolour the opening he had made, that it would look like an ancient rat hole instead of showing a clean bore, he would have some answer to give Brotherson when he came to question him in regard to it. But now the whole thing seemed up! He had shown himself a fool and by good rights ought to acknowledge his defeat and return to Headquarters. But he had too much spirit for that. He would rather--yes, he would rather face the pistol he had once seen in his enemy's hand.

Yet it was hard to sit here waiting, waiting--Suddenly he started upright. He would go meet his fate--be present in the room itself when the discovery was made which threatened to upset all his plans. He was not ashamed of his calling, and Brotherson would think twice before attacking him when once convinced that he had the Department behind him.

"Excuse me, comrade," were the words with which he endeavoured to account for his presence at Brotherson's door. "My lamp smells so, and I've made such a mess of my work to-day that I've just stepped in for a chat. If I'm not wanted, say so. I don't want to bother you, but you do look pleasant here. I hope the thing I'm turning over in my head--every man has his schemes for making a fortune, you know--will be a success some day. I'd like a big room like this, and a lot of books, and--and pictures."

Craning his neck, he took a peep at the shelves, with an air of open admiration which effectually concealed his real purpose. What he wanted was to catch one glimpse of that empty s.p.a.ce from his present standpoint, and he was both astonished and relieved to note how narrow and inconspicuous it looked. Certainly, he had less to fear than he supposed, and when, upon Mr. Brotherson's invitation, he stepped into the room, it was with a dash of his former audacity, which gave him, unfortunately, perhaps, a quick, strong and unexpected likeness to his old self.

But if Brotherson noticed this, nothing in his manner gave proof of the fact. Though usually averse to visitors, especially when employed as at present on his precious model, he quite warmed towards his unexpected guest, and even led the way to where it stood uncovered on the table.

"You find me at work," he remarked. "I don't suppose you understand any but your own?"

"If you mean to ask if I understand what you're trying to do there, I'm free to say that I don't. I couldn't tell now, off-hand, whether it's an air-ship you're planning, a hydraulic machine or--or--" He stopped, with a laugh and turned towards the book-shelves. "Now here's what I like.

These books just take my eye."

"Look at them, then. I like to see a man interested in books. Only, I thought if you knew how to handle wire, I would get you to hold this end while I work with the other."

"I guess I know enough for that," was Sweet.w.a.ter's gay rejoinder. But when he felt that communicating wire in his hand and experienced for the first time the full influence of the other's eye, it took all his hardihood to hide the hypnotic thrill it gave him. Though he smiled and chatted, he could not help asking himself between whiles, what had killed the poor washerwoman across the court, and what had killed Miss Challoner. Something visible or something invisible? Something which gave warning of attack, or something which struck in silence. He found himself gazing long and earnestly at this man's hand, and wondering if death lay under it. It was a strong hand, a deft, clean-cut member, formed to respond to the slightest hint from the powerful brain controlling it. But was this its whole story. Had he said all when he had said this?

Fascinated by the question, Sweet.w.a.ter died a hundred deaths in his awakened fancy, as he followed the sharp short instructions which fell with cool precision from the other's lips. A hundred deaths, I say, but with no betrayal of his folly. The anxiety he showed was that of one eager to please, which may explain why on the conclusion of his task, Mr. Brotherson gave him one of his infrequent smiles and remarked, as he buried the model under its cover, "You're handy and you're quiet at your job. Who knows but that I shall want you again. Will you come if I call you?"

"Won't I?" was the gay retort, as the detective thus released, stooped for the book still lying on the floor. "Paolo and Francesca," he read, from the back, as he laid it on the table. "Poetry?" he queried.

"Rot," scornfully returned the other, as he moved to take down a bottle and some gla.s.ses from a cupboard let into another portion of the wall.

Sweet.w.a.ter taking advantage of the moment, sidled towards the shelf where that empty s.p.a.ce still gaped with the tell-tale hole at the back.

He could easily have replaced the missing book before Mr. Brotherson turned. But the issue was too doubtful. He was dealing with no absent-minded fool, and it behooved him to avoid above all things calling attention to the book or to the place on the shelf where it belonged.

But there was one thing he could do and did. Reaching out a finger as deft as Brotherson's own, he pushed a second volume into the place of the one that was gone. This veiled the auger-hole completely; a fact which so entirely relieved his mind that his old smile came back like sunshine to his lips, and it was only by a distinct effort that he kept the dancing humour from his eyes as he prepared to refuse the gla.s.s which Brotherson now brought forward:

"None of that!" said he. "You mustn't tempt me. The doctor has shut down on all kinds of spirits for two months more, at least. But don't let me hinder you. I can bear to smell the stuff. My turn will come again some day."

But Brotherson did not drink. Setting down the gla.s.s he carried, he took up the book lying near, weighed it in his hand and laid it down again, with an air of thoughtful inquiry. Then he suddenly pushed it towards Sweet.w.a.ter. "Do you want it?" he asked.

Sweet.w.a.ter was too taken aback to answer immediately. This was a move he did not understand. Want it, he? What he wanted was to see it put back in its place on the shelf. Did Brotherson suspect this? The supposition was incredible; yet who could read a mind so mysterious?

Sweet.w.a.ter, debating the subject, decided that the risk of adding to any such possible suspicion was less to be dreaded than the continued threat offered by that unoccupied s.p.a.ce so near the hole which testified so unmistakably of the means he had taken to spy upon this suspected man's privacy. So, after a moment of awkward silence, not out of keeping with the character he had a.s.sumed, he calmly refused the present as he had the gla.s.s.

Unhappily he was not rewarded by seeing the despised volume restored to its shelf. It still lay where its owner had pushed it, when, with some awkwardly muttered thanks, the discomfited detective withdrew to his own room.

XVIII. WHAT AM I TO DO NOW

Early morning saw Sweet.w.a.ter peering into the depths of his closet. The hole was hardly visible. This meant that the book he had pushed across it from the other side had not been removed.

Greatly re-a.s.sured by the sight, he awaited his opportunity, and as soon as a suitable one presented itself, prepared the hole for inspection by breaking away its edges and begriming it well with plaster and old dirt.

This done, he left matters to arrange themselves; which they did, after this manner.

Mr. Brotherson suddenly developed a great need of him, and it became a common thing for him to spend the half and, sometimes, the whole of the evening in the neighbouring room. This was just what he had worked for, and his constant intercourse with the man whose secret he sought to surprise should have borne fruit. But it did not. Nothing in the eager but painstaking inventor showed a distracted mind or a heavily-burdened soul. Indeed, he was so calm in all his ways, so precise and so self-contained, that Sweet.w.a.ter often wondered what had become of the fiery agitator and eloquent propagandist of new and startling doctrines.

Then, he thought he understood the riddle. The model was reaching its completion, and Brotherson's extreme interest in it and the confidence he had in its success swallowed up all lesser emotions. Were the invention to prove a failure--but there was small hope of this. The man was of too well-poised a mind to over-estimate his work or miscalculate its place among modern improvements. Soon he would reach the goal of his desires, be praised, feted, made much of by the very people he now professedly scorned. There was no thoroughfare for Sweet.w.a.ter here.

Another road must be found; some secret, strange and unforeseen method of reaching a soul inaccessible to all ordinary or even extraordinary impressions.

Would a night of thought reveal such a method? Night! the very word brought inspiration. A man is not his full self at night. Secrets which, under the ordinary circ.u.mstances of everyday life, lie too deep for surprise, creep from their hiding-places in the dismal hours of universal quiet, and lips which are dumb to the most subtle of questioners break into strange and self-revealing mutterings when sleep lies heavy on ear and eye and the forces of life and death are released to play with the rudderless spirit.

It was in different words from these that Sweet.w.a.ter reasoned, no doubt, but his conclusions were the same, and as he continued to brood over them, he saw a chance--a fool's chance, possibly, (but fools sometimes win where wise men fail) of reaching those depths he still believed in, notwithstanding his failure to sound them.

Addressing a letter to his friend in Twenty-ninth Street, he awaited reply in the shape of a small package he had ordered sent to the corner drug-store. When it came, he carried it home in a state of mingled hope and misgiving. Was he about to cap his fortnight of disappointment by another signal failure; end the matter by disclosing his hand; lose all, or win all by an experiment as daring and possibly as fanciful as were his continued suspicions of this seemingly upright and undoubtedly busy man?

He made no attempt to argue the question. The event called for the exercise of the most dogged elements in his character and upon these he must rely. He would make the effort he contemplated, simply because he was minded to do so. That was all there was to it. But any one noting him well that night, would have seen that he ate little and consulted his watch continually. Sweet.w.a.ter had not yet pa.s.sed the line where work becomes routine and the feelings remain totally under control.

Brotherson was unusually active and alert that evening. He was anxious to fit one delicate bit of mechanism into another, and he was continually interrupted by visitors. Some big event was on in the socialistic world, and his presence was eagerly demanded by one brotherhood after another. Sweet.w.a.ter, posted at his loop-hole, heard the arguments advanced by each separate spokesman, followed by Brotherson's unvarying reply: that when his work was done and he had proved his right to approach them with a message, they might look to hear from him again; but not before. His patience was inexhaustible, but he showed himself relieved when the hour grew too late for further interruption. He began to whistle--a token that all was going well with him, and Sweet.w.a.ter, who had come to understand some of his moods, looked forward to an hour or two of continuous work on Brotherson's part and of dreary and impatient waiting on his own. But, as so many times before, he misread the man. Earlier than common--much earlier, in fact, Mr. Brotherson laid down his tools and gave himself up to a restless pacing of the floor. This was not usual with him. Nor did he often indulge himself in playing on the piano as he did to-night, beginning with a few heavenly strains and ending with a bang that made the key-board jump. Certainly something was amiss in the quarter where peace had hitherto reigned undisturbed. Had the depths begun to heave, or were physical causes alone responsible for these unwonted ebullitions of feeling?

The question was immaterial. Either would form an excellent preparation for the coup planned by Sweet.w.a.ter; and when, after another hour of uncertainty, perfect silence greeted him from his neighbour's room, hope had soared again on exultant wing, far above all former discouragements.

Mr. Brotherson's bed was in a remote corner from the loop-hole made by Sweet.w.a.ter; but in the stillness now pervading the whole building, the latter could hear his even breathing very distinctly. He was in a deep sleep.

The young detective's moment had come.

Taking from his breast a small box, he placed it on a shelf close against the part.i.tion. An instant of quiet listening, then he touched a spring in the side of the box and laid his ear, in haste, to his loop-hole.

A strain of well-known music broke softly, from the box and sent its vibrations through the wall.