The three men were now standing grouped about the table with its scattered books and manuscripts, and Ferrars bent toward Robert Brierly, putting a hand upon his shoulder.

"Brierly," he said, "sit down; this thing is using up your strength. I will tell you what I think of all this, and then we must lock up this place for a little while just as it is." And as Brierly obediently dropped into the chair which the doctor quickly placed beside him, the detective resumed.

"Since yesterday half a dozen theories have suggested themselves to my mind as possible explanations of this very daring murder, for I am now fully convinced that it is nothing less; but I make it a rule never to accept, much less announce, a belief, until I have established at least a reasonable series of corroborative circumstances. This I have not done entirely to my satisfaction, and so we will not go into the theory of the case, but will see what facts we have established; and fact number one, to my mind, is this: Your brother, Mr. Brierly, was most certainly shot down with malice aforethought. He could not have shot himself, and no one, in that open place, could have killed him by accident. He may have been entirely unaware of it, but he had an enemy; and the deed of yesterday was planned, I believe, long ago, and studied carefully in every detail."

Robert Brierly flushed and paled. He opened his lips as if to speak, but the detective's eyes were steadfastly turned away, and he resumed almost at once.

"I blame myself that I did not establish myself here last night, as I at first thought of doing. But it is too late for useless regret. And now, about this boy. Have you, either of you, a thought, a suspicion, as to his identity?"

The doctor shook his head.

"You can't suspect one of the pupils, surely?" hazarded Brierly.

"Be sure that Mrs. Fry knows every pupil in Glenville, by sight, at least; and this lad was a stranger, remember. It was a clever lad who first secured the key to these rooms and then decoyed Mrs. Fry half way across the town perhaps. How long must it have taken her, Doc, to go and come, in haste?"

"Quite half an hour, I should think."

"Well, we will assure ourselves of that later. Now we will suppose that this strange boy was acquainted with these rooms to some extent, and that he was, I fully believe. When Mrs. Fry is out of sight—and we know, from her story, that he was careful that she should be before he left his station upon the front porch—he slips indoors and evidently knows where to look for a lamp, which he does not light until he is inside this room." And Ferrars put a finger upon the match remarked upon by Mrs. Fry. "Now, as Mrs. Fry observed, there has been quite a film of dust in the air for the past twenty-four hours, so that, in spite of the good woman's tidy ways, it has accumulated upon this dark and shining wood." And he put down his finger and called their attention to its prints upon the table at his side.

"When we entered this room," he went on, "and I took it upon myself to look at that window with the swinging blind, under pretence of opening the shutters, I first noted that the visitor had left us a clue to his identity—several clues, indeed. Before seeing these I had thought that the boy was only an advance guard for some one else, but I see I was wrong. It was the boy, and a very keen and clever boy, who entered here alone. See upon this table, upon the window sills, and upon the desk, the prints of one, two, and sometimes all four, small slender fingers."

Ferrars paused a moment, while they examined the dust prints, faint but yet clear, upon the dark wood, and making lines of clearer colour upon the painted brown of the window sills.

"And what," asked Brierly, speaking for the first time since the detective began his explanation—"what was his real object?"

"His real object! Ah, I see you have been observant, and if I am not much mistaken he has left something; but the things he took were taken solely to cover up the real reason of his coming. Mr. Charles Brierly's pistol, his watch, and the foreign bijouterie were so little wanted by this remarkable boy that he will no doubt get rid of them in some way at the first opportunity. All but one thing."

"And that?" asked Brierly, breathlessly.

Ferrars walked over to the writing-desk and signed them to follow. "Observe that letter file!" he said. "There is not much upon it, bills for school books, two or three circulars, and so on, but observe that this file hangs over the top of the desk, so that anything falling from it would touch just here. He moistened the tip of a forefinger, and, touching with it a small bit of paper lying upon the top of the desk and just below the letter file, he lifted it deftly, and they all saw beneath it the dust of the previous day upon the polished surface.

"This," said Ferrars, holding out the bit of paper upon the palm of his hand, "was torn from something pulled from this file since Mrs. Fry dusted the furniture here yesterday morning, after Charles Brierly left the house. See, as the paper was pulled from the file this bit came off, because it was attached at the corner, as you see. It is a fragment from a newspaper. If it had been a letter the paper would not have parted so readily; it would merely have torn through."

It was, indeed, a tiny scrap of newspaper, not of the best quality, and not half an inch from the smoothly-cut corner to the ragged edge, where the file had perforated it.

"The slip of printed paper from which this was torn," said Ferrars, "was the one thing which was taken from this room because it was wanted! The rest were merely carried away as a blind."

"But," asked the doctor, "why did he make this search among the books and papers?"

"To find perhaps this very thing," replied Ferrars. "But his first and most important errand was this." He drew forth the letter given into his hands by Robert Brierly, and held it toward them. "Witness the thing itself. It bears no post-mark, it never did bear one, and it is thrust into the most conspicuous place, doubtless, after some looking about, in search of a better. I do not know its contents but I guess."

A gesture from Brierly cut short his speech. "Read it, both of you," he said, with something like a groan. "And tell me what it means."

Ferrars drew forth the sheet of note paper and slowly unfolded it. For a moment he scrutinised the page with a frown, and then began to read—

"Mr. Charles Brierly: I don't know why I should be drawn into your love affair any further, and I have said my last word about your friend, Miss G——. One would think that the proofs you have already had would be more than enough. She is not the first woman, with a pretty face and an innocent way, who has fooled and tricked a man. Why don't you ask her and have it out? You'll find she can scratch as well as the rest of her sex. One word more, when you have had it out with her, beware! Especially if she weeps and forgives you. Remember the 'woman scorned.'

"Don't write me again. I shall not answer any more questions. And, remember your promise, don't let her dream that you ever heard of me. I shall feel safer. So good-bye and good luck. Yours, J. B."

Ferrars folded up this strange letter slowly, saying:

"This document has no date and no post office address." He held it in his hand for a moment in silence, looking at it thoughtfully, then. "I should like to retain this," he said, looking at Brierly, "as one of the documents in the case." And as Brierly silently bowed his assent, he added: "Have you formed an opinion concerning this letter?"

"I believe it is a shameful trick," declared Robert Brierly, hotly. "An attempt on the part of some person or persons to injure Miss Grant, who stands to me as a sister henceforth. If I am any judge of womankind, she is as good as she is lovely, and I believe that she mourns my brother's awful death as only a good, true and loving woman can. I wish you could and would say the same, Mr. Ferrars."

"I can say that you have said the only right and manly thing, in my opinion. You don't want to know what I think, however, but what can be done? And, first, this affair must be kept between ourselves. This letter makes it all the more important. If it has been put here to mislead justice and to make trouble, perfect silence regarding it will be the most baffling and perplexing course we can pursue. And it may lead to some further manifestation. The word must go out at once that Mr. Brierly has desired these rooms closed for the present, with everything to remain untouched. Meantime I consider that we have got our hands upon some strong clues, if we can find the way to develop them aright. Don't ask me anything more now, gentlemen. I want time to study over this morning's discoveries, and Mr. Brierly, it is time you breakfasted."

At this moment there came a quick tap at the door, and Mrs. Fry's voice was heard without. At a signal from Ferrars, Doctor Barnes opened the door.

"Gentlemen," began the little woman in eager explanation, "I don't want to interrupt."

"We are just going," said the doctor politely.

"Oh, well, I got to thinking, after I went downstairs, and it came into my mind that I didn't see Miss Grant's picture on the top of the writing-desk up here. Mr. Brierly had had it three weeks or so, and he showed it to me himself and says, 'Mrs. Fry, this picture is in its proper place here in my room. You and Nellie both know and love Miss Grant, and so I may tell you that she is to be my wife some day, God willing.'" The woman's voice broke at the last word, and Robert Brierly made a quick stride back toward the desk. But Ferrars said, unconcernedly, "Thank you, Mrs. Fry; we shall find it in the desk, I fancy," and then he explained to her Mr. Brierly's desire that the rooms remain closed to all curious visitors until further notice, adding that they would close the outside blinds and be downstairs directly; then, shutting the door upon the woman's retreating form, and softly turning the key in the lock again, Ferrars went to the desk, and, catching back Brierly's extended hand, said, "Wait!"

He came closer to the desk and bent to scan at the top shelf.

"Look," he said after a moment, "do you see that line, close to the back, where the dust is not quite so apparent? The picture has been taken from there." He took hold of the back and pulled the desk from the wall a few inches.

"Ah," he exclaimed, "I thought so!" and dropping upon one knee he drew out two pieces of cardboard. "I thought so," he repeated as he arose, and there was a steely gleam in his eyes as he held out to view the two halves of a fine picture of Hilda Grant, torn across the middle as if by a firm and vindictive hand. "This helps me," he said, with a touch of triumph in his voice. "It helps me more than all the rest."

He made a movement as if to put the picture together with the letter which he had put down upon the desk-top, into a capacious inner pocket, and then suddenly withdrew his hand and bestowed them elsewhere, for, thrust into that safe side pocket, so convenient and capacious, was a folded newspaper, from which a "clipping" had been carefully cut, a paper which he had found in the rack near the desk, and had secreted, as he thought, unseen, at his earliest opportunity.