Scanlon and Nora Cavanaugh were hurrying through the vast waiting-room at the railroad station when the big athlete felt a touch upon his arm.

"Not that way, old chap," said a voice at his side.

It was Ashton-Kirk, smiling and unruffled, and near by stood the broker, Quigley. Nora gave a gasp of despair, and Scanlon felt her cling to him, tremblingly.

"Fenton is outside there," resumed the investigator, nodding his head toward the train shed. "I have a notion that he's on his way to Stanwick. If you go out, he'll see you."

Bat gave a sigh of relief; after all, his own mission and that of Nora was not suspected.

"Is Fuller trailing him?" he asked.

"Yes; he just gave me the word as he passed."

Quigley, as he stood waiting, had a most uncomfortable expression upon his face; he stood first upon one foot and then upon the other; evidently what was in prospect for him was not at all to his liking.

"Mr. Quigley and myself had intended taking the train for Stanwick," said Ashton-Kirk. "But I think now that we'd better not."

"Not go?" It was Nora who spoke, and there was eagerness in her voice.

"Not by train," smiled the investigator.

"What's your idea of going there to-night?" asked Bat, with an assumption of ease.

"Why, I might ask you that, old chap," said the other, thoughtfully, "but I won't. But my errand is no secret. It's a little matter of identification."

At this moment Quigley advanced, and with a bow to Nora said:

"If I have been an innocent instrument—perfectly innocent, mind you—in the hands of a designing person, Miss Cavanaugh, I beg your pardon. I was assured that the jewels were honestly come by; and when Mr. Ashton-Kirk told me a while ago that they were really your property, I immediately placed myself in his hands, most anxious that complete justice should be done."

Nora made a vague answer to this, for at the moment she was watching the investigator, who stood with narrowed eyes, a thoughtful wrinkle between his brows, and one hand stroking his chin. And as she watched him, he spoke to Scanlon.

"It may be," said he, and there was a slow, curious smile about the corners of his mouth, "that Fenton's blundering into my plans will not be serious, after all. Indeed, it may be turned to account." The singular eyes went to the girl. "You are interested in this case, Miss Cavanaugh, and so is Scanlon. Why not go with Mr. Quigley and myself, and witness its solution."

"Fenton will spot us," said Scanlon. He had still a hope of doing what he and Nora had set out to do, and the pallor of her beautiful face and the misery in her eyes urged him to lose no chance. Once out of sight of the keen eyes of the investigator, he and the girl could take a taxi and make for Stanwick with all speed.

"Not if we go by motor," said Ashton-Kirk, in answer to his objections. "We can do that and make as good time as the local."

"Taxicabs are so small," said Nora, as they descended a long flight of steps to the street. "Four will crowd one so."

In her mind was the same thought as in that of Bat's. Once let them divide into two parties—she and Scanlon making one—and she was quite sure that their cab would be the first at No. 620 Duncan Street. But the investigator dashed this hope by leading the way, when they reached the street, to where some touring cars were to hire near the station.

"These," said he, quietly, "will be comfortable."

There was a businesslike young man in charge of the first of the cars, and he made his bargain, cranked his engine, received his orders and started off in an amazingly brief time. Inside of twenty minutes the suburbs, with their long rows of villa-like buildings, and their wide and smoothly paved streets, began to swing past them.

"I have your interest to thank, Miss Cavanaugh," said Ashton-Kirk, "for bringing this case to my attention—as a participant, that is. There has been a simplicity in it which has attracted me from the start, and, at the same time, a curious interweaving of threads which, under almost any other set of circumstances, would have been as wide apart as the poles. Scanlon has gone partly over the route with me, and because of this interweaving I have had considerable trouble in preventing his jumping at conclusions—in taking appearance for granted without waiting for proof. I am not sure how far I kept him from error," with a nod and a laugh, "for several times I believe he has gone the length of suspecting you."

Nora made no reply to this, but Scanlon said:

"I have believed she did it; everything pointed that way. But I never blamed her, for she had cause enough, even for that."

Ashton-Kirk nodded gravely.

"Cause, yes," said he. "And that is the heart-breaking thing connected with crime of a certain sort. Sometimes the criminal is much more innocent than the victim." He sat thoughtful for a space, while the car bounded forward over the well-kept roads; then he resumed: "I could see, Scanlon, where and how your thoughts flowed as they did; but I could do nothing more at the time than tell you to make no snap judgments. The agitation of Miss Cavanaugh caught your attention in the first place, and so when we saw a woman's footprints by the rose arbor you concluded they were hers; we found a small revolver by the fence; that also made you think of her. When, by means of the particle of mortar on the bar of the cellar grating at Stanwick, I discovered that the same person who had prowled about the lawn on the night of the murder had scaled the scaffolding outside Miss Cavanaugh's window, you fancied this to be almost positive proof. What you saw at Bohlmier's hotel, and the story told you by Big Slim, made it almost damning.

"If you had waited, as a man more experienced in such things would have done," and the investigator smiled at his friend, "you would have saved yourself a state of mind. The prints at the rose arbor were made by a certain sort of shoe—a kind which I felt sure Miss Cavanaugh never wore. Later, in a second visit which I paid to No. 620 Duncan Street, I found the shoes which made the prints, and still with particles of soil clinging to them."

Bat caught a little moan from Nora, and he held her cold, limp hand in his strong, warm one.

"You're sure of that?" said he, to Ashton-Kirk.

"Quite positive. And the matter of the little revolver picked up on the lawn: that belonged to Fenton; he probably dropped it in scaling the fence. By means of a strong glass I saw a number scratched on the metal of the butt. I at once knew this to be a pawnbroker's mark. Fuller, inside three hours, had located the pawnbroker, and the records of the place showed the weapon had been sold to Fenton only a little while before."

"Good work!" admired Bat. "Nice!"

"And speaking of Fenton," went on Ashton-Kirk, "it rather puzzled me at first how he had been over the ground about the house and left no trace. But a little attention and look at his feet showed me that I had seen his tracks all over one side of the lawn—the ones of the man walking on his toes—and that I had supposed them to be those of Big Slim before he put on his 'creepers.'"

"Tell me," said Scanlon, "have you ever, in the course of this affair, believed young Frank Burton guilty?"

"At first I did not know. But after my second visit to Duncan Street, and a little talk with the colored maid, who is an honest imaginative soul, I was convinced that he was innocent."

"What did the maid tell you?" asked Bat.

"After the Bounder had been admitted to the house that night, she had gone back to the kitchen to her work. She heard Frank come in, but she did not catch anything of the altercation which followed. A little later, her duties finished, she started for her room which was at the top of the house. As she passed along the hall, on the second floor, she noticed the door of the bath room standing open and remembered she had not supplied it with fresh towels. The linen closet is in a room at the far end of the hall; she went there and procured what she wanted, and as she came into the hall once more she saw young Frank Burton come quickly out of his room, stand at the head of the stairway for a moment as though listening, and then hurry down to the floor below."

"That must have been after he had taken his sister to her room," said Scanlon.

But Ashton-Kirk shook his head.

"No; a few minutes later the maid saw him ascend the stairs once more, and the sister was with him then."

"But," cried Nora, a vague fear as to what this might lead to in her mind, "when the maid was questioned by the coroner's physician she said——"

But the investigator stopped her.

"As I have said, the maid is an altogether unimaginative creature, and it never occurred to her that anything short of blows or outcries could have anything to do with the crime. It was plain to me, as I talked to her, that she had even then no notion of the importance of what she was saying. She was simply answering questions. However, added to what the nurse had told Dr. Shower, her information was vital, indeed. Miss Wheeler had gone into the kitchen, if you recall her testimony, at a time when the three Burtons, father, son and daughter, were in the sitting-room. She said she had gone to tell the maid she might go to bed, and found she had already gone; also she remained in the kitchen for a space, attending to some duties of her own.

"During this interval young Burton must have gone to his room, probably sick at heart with the wrangling. His haste in emerging from the room, when the colored girl saw him later, and his pause to listen at the head of the stairs seem to indicate that something had attracted his attention below."

"Have you any idea what that was?" asked Scanlon.

"I am not yet sure. But this is how it builds up in my mind. When he reËntered the sitting-room he found his father dead and his sister in a faint. Having, of course, a full knowledge of certain nervous seizures to which his sister was subject, it rushed upon him that, in a moment of frenzy, she had killed her father."

"No!" cried Nora Cavanaugh. "Oh, no!"

"He's only supposing," said Scanlon, soothingly. "That's nothing at all."

"The young man's brain is a quick one," proceeded Ashton-Kirk; "any one who follows his work in the Standard knows that. He at once began to cast about, so it seems to me, for a way of concealing his sister's guilt. He took her to her room, and came down once more to the sitting-room. Allowing for a proper passage of time, he then asked the nurse to call in the police. To them he told the story which he afterward repeated to the coroner's physician: that his father had met his death in the space which had elapsed between his taking his sister to her room and his return to the sitting-room."

Bat looked at Nora; in the semi-dark of the car her face was drawn and despairing. There was not a ray of hope in Scanlon's own breast, and patiently he listened as the quiet voice of the investigator went on:

"The by-play between the young man and the girl, during their examination by Dr. Shower, which you reported so graphically to me, took my attention. He must have seen suspicion heading his way, and yet he took no real steps to prevent it. And then there was something else. You reported that he had appeared in the sitting-room after you had gone there with Osborne and Dr. Shower to examine the body; and his anxiety then concerning the nature of the instrument used in the commission of the crime struck me as being a bit unusual. He seemed to dread, apparently, that this would be shown to be something caught up on the spur of the moment, something belonging in the room. Without putting it in so many words, he seemed to insinuate that a regulation weapon, such as might have been brought into the house by an unknown, had been used. In this I seemed to detect not only a desire to throw the police off the track, but also the existence of an element of hope. In the back of his mind was the thought that, after all, his sister might not be guilty. If the weapon used was not one that had been ready to her hand, there was a chance that she was innocent.

"However, the finding of the candlestick must have dissipated this hope, and when they charged him with the crime, he merely denied it; he, I think, feared to do or say anything which might direct the attention of the police definitely away from himself; for, in doing this, they might chance to think of his sister."

"But," said Nora, "you have no proof that all of this is true."

"Not proof," said Ashton-Kirk, smiling. "But there are certain almost unmistakable indications. One of these I brought about by my confidence to the police regarding the possibility of a woman being connected with the case. I felt that if he believed his sister guilty that this would stir him to some further action. It did, as you know. He instantly canceled his denials, and admitted the crime."

"Tell me," said Scanlon, "haven't you ever thought that maybe some one else had done this thing? Has your mind always been fixed on these two? For example, didn't you, also, once think Miss Cavanaugh had a part in it?"

"Not for a moment," smiled Ashton-Kirk.

"Not even when I told you how I'd seen her at Bohlmier's?"

"Not even then. Of course I didn't know the explanation of that, and at once set about finding one. Fuller was put to work looking up Bohlmier, and in one day had his record complete. The man is a skilful blackmailer; he has practiced in many cities and has served more than one term in jail. I knew at once what had occurred; the two men fancied they 'had something on' Miss Cavanaugh regarding this murder, and had endeavored to extort money from her. I leave it to you," with a smiling nod toward Nora, "to tell how near I am to the facts."

The girl made a low-voiced, unintelligible reply, and then they ran on for some distance in silence. Suddenly Ashton-Kirk signaled the driver and the car came to a stand; the investigator pointed to some buildings at no great distance; a locomotive with a few cars trailing behind it was panting laboriously away from these, its headlight glaring morosely into the darkness.

"I think," said the investigator, "that is Stanwick Station."

"It is," agreed Scanlon.

"Then, more than likely, that is the train which carried Fenton and Fuller. I suppose it would be as well if we got out here and walked the remainder of the way."

Accordingly they alighted, and the driver was instructed to wait where he was. Then they proceeded toward Duncan Street, reaching which they turned into it, and soon were in the neighborhood of No. 620. They paused in the shadows in which Bat Scanlon had spoken to the old resident; the house opposite seemed dark and silent.

"No one stirring," said Bat. "This whole section can be as quiet a place as I know of when it takes the notion."

Ashton-Kirk, who had been straining his eyes through the darkness, now placed his fingers to his lips and gave a peculiar whistle. After a moment there was an answer to this, and then a figure emerged from the shadow of the Burton house. In a very little while longer Fuller crossed the street to them.

"What news?" asked the investigator, briefly.

"Fenton is in the house," answered Fuller. "I followed him from the train; he went to the front door, rang in the regular way and was admitted by what looked to me to be a nurse."

"Had he any idea he was followed?"

"I think not. He made no show of it, anyhow."

"Suppose you stay here and keep Mr. Quigley company for a few minutes," suggested Ashton-Kirk. "We'd like to look around a bit."

"I am not accustomed to the night air," complained the broker. "It has a bad effect upon my breathing."

"We shall be only a very little while," he was assured.

Ashton-Kirk crossed the street with Nora and Scanlon at his side. Quietly they entered at the little iron gate and stood for a space examining the house.

From the fan light above the front door came a dull glow, as though a subdued light burned in the hall.

"All the shutters are closed," said Bat, as he noticed this fact. "They may be brightly lighted inside and we not know it."

The keen, searching eyes of Ashton-Kirk caught a sort of glow upon the grass at one side; he moved in that direction and the others followed him. At the second floor a light flickered dimly in a window; it was a wavering, uncertain sort of thing, and Bat Scanlon recognized it at once.

"It's candle-light," said he. "Remember, I told you about seeing the girl——"

Here he felt Nora's cold hand close upon his wrist; at the window appeared the figure of Mary Burton, in the same loose gown as before and holding a candle in her hand. The light was full upon her face as she bent forward as though intent upon catching some sound. And the face was white and rigid with fear.

"Have you looked through the upper part of the house?" Ashton-Kirk asked Scanlon.

"No," replied Bat.

"I have," said the other. "That window is right at the head of a stairway. Something is being said or done upon the lower floor which rather upsets her."

He moved forward as he spoke; beneath the dimly-lighted window above was a square, heavily made shutter different from the others in shape, and marking a hall window. As they were about to pass it, Ashton-Kirk uttered a low exclamation and stopped suddenly. The shutter was badly fitted, having swollen with the weather, so that it could not be completely closed. The slim, strong fingers of Ashton-Kirk gripped its edge; slowly, carefully, with never a creak it opened. There was a white curtain inside, but a pendant light made all things in the hall visible. A flight of stairs led to the second floor, and at the foot of these stood Fenton, one hand upon the rail, and the nurse, with frightened face, was pleading with him, as though not to do something which he had signified his intention of doing.

"Ah!" Scanlon heard Ashton-Kirk breathe. "So that's your game, is it?" Then to Bat: "Stay here; keep an eye on that fellow, and be ready to act."

With these words he slipped easily away into the darkness, and Scanlon and Nora were left alone at the window.

"He is demanding to be allowed to see Mary," said the trembling voice of Nora in Bat's ear. "And the poor nurse is terrified. See how she tries to stop him!"

With a sort of snarl, the broken-nosed man threw off the detaining hand of the nurse and turned a threatening face upon her, at the same time gesturing toward the upper floor and signifying his intention of ascending in spite of anything the girl might say.

"But she's got grit," said Bat, in a low tone of admiration. "She hangs to him. The girl up-stairs is her patient, and she'll not have her frightened. It's part of the training they get, I guess."

Fenton let go the stair rail and made a step toward the nurse; his ugly face was distorted, and his hands were clenched. He began to speak; what he said could not be heard by the watchers outside the window, but the nurse seemed terrified and shrank from him.

"He's down to cases now," said Scanlon, as he deftly freed his revolver, and held it ready, but in such a way that Nora could not see it.

"Look!" whispered Nora, thrillingly. "Look, Bat. On the stairs!"

Bat Scanlon shifted his eyes from the threatening figure of Fenton, and the shrinking one of the nurse; upon the stairs, coming slowly down, her loose dressing-gown held about her by one slim hand, was Mary Burton. She had reached the foot of the stairs before the broken-nosed man saw her; then he whirled about, and his hands gripped her delicate throat.

Scanlon's revolver arose to a deadly level, but before he could fire, Ashton-Kirk was seen to leap into the hall like a panther. There was a short, sharp blow, with all the power of the lithe body behind it; Fenton's grasp relaxed and he fell to the floor. The watchers saw Mary totter, and noted Ashton-Kirk catch her in his arms, at the same time gesturing to the nurse to bring a restorative. The nurse had vanished, and Ashton-Kirk was placing the sick girl upon a hall lounge when Nora and Scanlon hurried from the window and around to the door.

This stood wide open, and they encountered Fuller and the pawnbroker, Quigley, as they entered. In the hall they saw Fenton rising sullenly to his feet, one hand feeling at his jaw; Ashton-Kirk was bending over the white, fragile creature upon the lounge.

"There she is," said Scanlon, pointing to Mary and looking at Quigley. "There she is. Pile it all on her shoulders. She's strong and can stand it. Say your say, and then beat it; for by George, I won't be able to stand the sight of you afterward."

Quigley looked at the speaker in surprise; then his puffy eyes went to Mary with a deepening of their astonishment, and finally to Ashton-Kirk.

"Is this the lady you had in mind?" said he. "If so you have made a mistake. She is not the person who sold me the diamonds."

Nora Cavanaugh gave a gasping sort of cry and stood staring at the pawnbroker, her wide eyes full of joy—of bewilderment. At that moment a set of hangings were pushed aside and the nurse came into the hall, a glass in her hand. Silently Ashton-Kirk touched Quigley upon the arm, and pointed to the nurse. The man started, and then regarded her intently.

"Yes," said he. "Yes! That is the woman! I can take my oath on that in any court in the land."

The woman stood motionless for a moment; she drew in a long breath; the glass fell to the floor and smashed. Then she disappeared once more through the door by which she entered.

"Fuller," said Ashton-Kirk. But he had no need to speak, for that brisk young man was already after her. Dazed, Bat Scanlon looked about. Nora was upon her knees beside the sick girl, sobbing and chafing her pale hands; the investigator was at a telephone summoning the police. Scanlon's glance then wandered to Fenton, and there rested.

"You told us a couple of hours ago," said he, "that a woman killed Tom Burton and that you saw her do it. Has he," and he nodded toward Quigley, "got it on the right party?"

"Yes," replied the broken-nosed man, "he's got it right; it was the nurse. You don't have to look any further than that."

"But," said Bat, a last doubt in his mind, "what was the idea of you wanting to go up-stairs a while ago, if you didn't want her?" pointing to Mary.

"It was the sparks I wanted," said Fenton. "I thought if any were left they were in the nurse's room."

Next morning Nora Cavanaugh, still very pale, but with a light in her eyes such as had not been there for many days, sat snugly in the corner of a sofa at her home, wrapped about in a beautiful old shawl. Near by sat Bat Scanlon; and standing before them, his hat and stick in his hand as though about to leave, was Ashton-Kirk.

"I'll admit," the big athlete was saying, "when the thing was finally brought down to a woman and Nora was eliminated," with a smiling nod toward her, "I could see nobody but Mary Burton. The nurse never occurred to me."

"And yet you seem to have suspected her from the start," said Nora, her eyes wonderingly on the criminologist. "Why was that?"

"It began with the candlestick—the weapon used in the commission of the murder. Candlesticks go in pairs, usually. I found the mate to it on a shelf in the room across the hall from the sitting-room—that in which the nurse sat reading when Tom Burton was admitted to the house. That one of a pair of candlesticks should be in the sitting-room, and one in the room opposite, struck me as being unusual; later, I spoke to the maid of this. She said they both belonged in the room—on the shelf—where I found the second one."

Nora gave a little gasp, and her hand went to her heart.

"It is horrible," she said.

"While on my second visit to Duncan Street, I was at pains to note one of the nurse's shoes; it was of a peculiarly comfortable make—the same as those which made the prints at the rose arbor.

"These two things rather centered my attention upon her; and I began to pry into her record. Burgess, one of my men, went as far as New Orleans, looking her up. A number of things were found against her, a few rather startling. She seemed a woman given to criminal impulses, and just the sort who would perpetrate a thing such as the Stanwick affair."

"And she had a good face," said Nora. "I had specially noticed it. To think," and the girl shivered, "that she should have been a suicide, locked in her room, when the police came!"

"Fuller made a mistake in waiting when she refused to open the door," said Ashton-Kirk. "He should have broken it in."

"Her story of how the murder was done would have been interesting," said Scanlon.

"I think I can, with Fenton's statement to help out, supply the main points," said the investigator; "but of course they will lack the personal touch. As I have worked it out, she sat reading, just as she said; and she heard a greater part of what was talked of in the sitting-room between Burton and his daughter, and afterward the son. I have learned why the elder Burton went there that night. It was to call up and confer with a shady dealer in diamonds—just such another as Quigley. I have talked with this man. He said he'd had a call from the Bounder, who told him he had a rich haul to dispose of. The time of this call and the time of the Bounder's presence at No. 620 Duncan Street was the same. But the place where they were to meet was never given to the dealer, for the call terminated abruptly in a confusion of voices, and then a blank silence which told him that the receiver had been hung up. I explain this by reasoning it out that young Burton, indignant at what was going forward, had torn his father away from the instrument before the conversation had ended."

"But, if this is so, why did the Bounder ever go to No. 620 Duncan Street to carry out a deal for stolen diamonds?" asked Scanlon. "There were many perfectly safe places he could have picked."

"The answer to that probably lies in the nature of the man. He hated his son and daughter; he knew his rascally doings gave them pain, and it may have occurred to him as a delicious piece of humor to do this particular thing before their eyes, depending upon their shame to keep them silent afterward.

"All this talk of diamonds attracted the attention of the listening nurse. She finally stole out of the house, took up the position at the rose arbor and watched what was happening in the sitting-room. While she was doing this, I think young Burton must have gone up-stairs, where he was afterward seen by the maid. From what Fenton has told the police, he was looking in at the sitting-room window when he saw Mary Burton faint. No one was then in the room but the girl and her father; and as the latter bent over her, Fenton saw the door open and the nurse steal into the room, the brass candlestick in her hand. The jewels were upon the table where the Bounder had placed them at the moment his daughter fell. The nurse snatched them up, and as she did so the man turned his head and saw her. He leaped toward her, and she struck him to the floor. Without a moment's hesitation she lifted the window, and dropped the candlestick within two feet of where Fenton was crouched. Then she left the room.

"The sounds made by these happenings are probably what young Burton was listening to at the head of the stairs when the colored maid saw him. And my version of what he did after he descended the stairs you have already heard. The brother thought the sister was the criminal, and when the sister came out of her swoon—I heard her admit as much to her brother this morning when he was released from prison—her mind was burdened with the belief that he was guilty. And so both were silent for each other's sake."

"But Mary's prowling about the house with the candle as I saw her that night?" said Scanlon. "What do you make of that?"

"Mary Burton has a good mind—though she lacks self-assertion. When the jewels were not found upon her father's body, or in the room where he was killed, she realized they had been stolen. But by whom? She knew her brother too well to think he was the thief, and I think from that moment she began to suspect the nurse. Once, as a report of one of my men states, as the nurse left the house secretly and with a veil over her face, Mary was seen at a window, the curtain partly drawn aside, looking after her. I think her going about through the rooms with the candle was an effort to locate the possible hiding place of the diamonds."

Nora gave a deep sigh.

"Poor thing! And to think how very brave she was."

"Well," and Ashton-Kirk showed unmistakable signs of going, "I suppose their troubles from that source, at least, are over."

Nora arose and held out her hand.

"That it is," she said, "is due to you. And I thank you for the peace you have brought to us all."

Ashton-Kirk released the hand after a moment.

"It was one of those things which would probably have unraveled itself," said he. "However," with a nod and a smile which showed his flashing white teeth, "you never can tell. So it's just as well, perhaps, that it wasn't permitted to run its course." He paused in the doorway, the trim maid waiting to show him out. "That you are a friend of Scanlon's means a great deal to me," said he. "I'd do a great deal for him, for, you know, he's one of the very best fellows in the world."

And the last thing he saw as he vanished through the doorway was the undoubted blush which colored the face of Scanlon, and the light in the beautiful eyes of Nora Cavanaugh, as she turned to look at him.

[1] For the details of the Campe case, see the volume entitled: "Ashton Kirk, Special Detective."