"Eleanor," said Hilary, coming into the hall one afternoon with a couple of books in her hand, "if you are going out I want you to go to Smith's, please, and change these two library books for me."

It had been raining all day, and though the rain had now changed to a slight drizzle a thick mist creeping on from the sea had already blotted out the downs, and was hanging like a low cloud over the town. It was as cheerless an afternoon as could well be imagined, and Margaret who, suffering from a bad cold in her head, had not been out for a couple of days, hesitated a moment before replying. But the request was couched in such a peremptory tone that she did not quite like to refuse it. After all, since the children had gone away she was doing absolutely nothing in return for her board and lodging, and, since Hilary had forgotten that she was nursing a cold, it would have seemed ungracious to remind her of the fact.

But Hilary had not forgotten Margaret's cold. Had it been ten times as bad, however, she would still have despatched her on this errand. For the long-awaited, carefully planned-for moment when she could bring home Margaret's guilt to her had, in Hilary's confident estimation, at length arrived. A few minutes since, rummaging in the dressing-room next Margaret's room in search of some gloves that needed cleaning, she had chanced to espy under the bed the trunk in which the boys had hidden the Colonel's property. They had supposed it to belong to their mother, but Hilary knew that it was Eleanor's.

Rendered thoroughly uneasy by the continued stir that Colonel Baker was making about his loss, Jack and Noel had determined to smuggle his things out of their house and to deposit them somewhere in his garden, where he could easily find them, and to that end they had been trying, but without success so far, to open the trunk with various keys belonging to their mother. And it was the sight of these keys scattered about beside the trunk that had fired Hilary's detective ardour. What was Eleanor doing with her mother's keys? It could be for no good purpose that she had secreted them under the bed.

Without more ado, Hilary made up her mind to search that trunk. And the first thing to be done was to secure herself against interruption. So she invented an errand to take Eleanor out of the house for an hour or two. The others were all down at the rink, and having seen Margaret start, Hilary sped up to the box-room, secured a few keys, and set to work.

Two or three keys were tried in vain, but the fourth turned easily in the lock, and with hands that fairly trembled with excitement, she threw back the lid. The tray was empty. She lifted it out, and as she did so gave vent to a little cry of triumph. For there, at the bottom, reposed a bundle tied up in a gold embroidered scarlet Indian tablecloth which any one in Seabourne who had read any recent numbers of the local papers would have recognised immediately as Colonel Baker's missing property.

Literally pouncing upon it, Hilary dragged it out of the trunk and untied the four knotted corners, when out fell the tumbled contents of the Colonel's plate-basket—the big morocco case which contained his family miniatures, his Etruscan bronze vase, and his collection of gold coins.

All things considered, Hilary took her astonishing discovery very calmly. After all, it was only what she had been expecting. Her chief sensation at that moment was one of surprise that the trunk did not also contain the proceeds of the two other robberies. Probably, however, they would be found in Miss Carson's bedroom. Had she not been so obsessed by the idea that Miss Carson was the burglar with whose exploits the town had been ringing of late, Hilary might have hesitated before taking the step of searching the room of a girl who was, to all intents and purposes, a guest in their house. But the idea that she was doing anything disgraceful never occurred to her. The zeal of the amateur detective was far too strong upon her to leave room for reflections of that sort. She opened the door of Margaret's bedroom and went in. The room was exquisitely neat, for not only had habits of tidiness been inculcated in Margaret since she was old enough to fold a garment, but the spacious bedroom allotted to her at The Cedars, with its big mahogany hanging wardrobes and its deep chest of drawers, contained so much more room than she needed that there would have been no excuse for any one to have been untidy.

At first it seemed to Hilary that her search here was going to be unrewarded; the cupboards and drawers in which Margaret kept her dresses were soon searched through and revealed nothing at all of a suspicious nature. The two top drawers then underwent an examination, and the orderly little piles of veils and handkerchiefs were ruthlessly tumbled about by Hilary's eager hands. But all in vain. There was no vestige of a proof here that Miss Carson had had a hand in the two first burglaries as well as in the last. Feeling baffled and quite unreasonably indignant, Hilary turned her attention next to the dressing-table. The toilet articles on it were few and simple, and Hilary was about to turn away, when her eyes were caught by Margaret's gold watch and chain, which were hanging on a small velvet stand. The watch was an old-fashioned one, with an open gold face, and the long slender chain was also of gold. Attached to it were a watch-key and a very small steel key.

Hilary remembered that Miss Carson invariably wore the watch and chain, so that this small key evidently fitted something that she was careful always to keep locked up. As Hilary picked up this key the chain slid away from it, and she saw that the spring of the swivel was broken. That accounted, then, for the fact that Miss Carson was not wearing her watch, as she usually did. And when she left it on the dressing-table she had evidently forgotten that she was leaving the little key, which as a rule she was so careful to wear, lying about too.

Criminals, Hilary reflected with immense satisfaction as she picked up the key, always did forget important things of that sort. Now what did that little key fit? Evidently some bag or some small box which contained something that it behoved her to keep carefully concealed from every eye but her own. Now, where could that bag or box be, Hilary wondered, as she glanced round the room. Were there any drawers or cupboards that she had not yet thoroughly searched? Yes, there was the big bottom drawer in the wardrobe, in which Miss Carson kept her hats. She had looked into it once, but seeing that it apparently contained nothing but the few simple hats that the holiday governess owned, had pushed it to again. But now, feeling that that cursory glance had not been sufficient, Hilary knelt down before the wardrobe, and putting her hand to the back of the drawer, pulled out Margaret's morocco dressing-bag. It was the work of a moment only to fit the key in the lock, and then its contents were at the mercy of her prying eyes. But beyond the leather-covered case that Margaret had shown to Eleanor in the train the bag was empty, and Hilary, who had expected to find it crammed full of jewellery, experienced a sharp pang of disappointment. But when she opened the case and saw the pearl-studded locket and the beautiful row of pearls that formed its chain, her face brightened. The initials "M. A." on the back of the locket, to say nothing of the fine, copper-plate inscription, "For my daughter Margaret," that ran round the narrow gold setting of the miniature, were, of course, conclusive proof that it did not belong to Miss Carson. Hilary remembered, too, the handkerchief embroidered with those same incriminating initials which Miss Carson had one day dropped in the garden. Though it seemed to Hilary an unimportant matter now, she yet looked upon it as a link in the long chain of circumstantial evidence which she alone and unaided had forged against Miss Carson. Really, she thought, she had a right to be proud of herself, for had she not shown more intelligence and acumen in the detection of the Seabourne burglaries than every police official in the town. How every one would admire her skill! Her portraits might possibly appear in the illustrated papers, and as for the local papers, they would, of course, print long accounts of the marvellous way in which, working quite alone, she had succeeded in unravelling the mystery that had baffled the whole of the Seabourne police.

And as Hilary sat there pluming herself on her cleverness and lost in the pleasant dreams of the fame that would be shortly hers, the door opened, and Margaret, who had only just come back and was still in her outdoor things, walked into her bedroom.

It was not until she had advanced some way into the room that she saw Hilary, and then Margaret came to a sudden halt in sheer amazement at the scene that greeted her. Her astonished gaze travelled from Hilary round her room, with its disordered aspect, its open cupboards and ransacked drawers, and then she looked again at Hilary, who, with the open morocco case in her hand, met her eyes defiantly.

"Will you tell me, please, what you mean by this conduct, Hilary?" she said, feeling almost too amazed to be angry.

"Oh yes, I will tell you fast enough," Hilary said, who had been as taken aback by Margaret's sudden entry as the latter had been to find her there, and who, considerably to her own surprise and annoyance, was conscious of a distinct feeling of shame at the position in which she had been caught. But as she scrambled to her feet and faced Margaret she shook off that feeling. After all, it was for the latter to feel ashamed, not for her.

"You are found out," she said slowly and emphatically. "I have found you out."

"So," Margaret thought then, "it had come at last. Hilary, poking among her possessions, had somehow discovered her real name. Oh, poor Eleanor! What would happen to her now?"

"You ask me what I mean by coming into your room; but that's nothing. It is for you to explain how you dared to come into our house, a thief and a burglar like you. But I," throwing out her arm dramatically, "have unmasked you."

If Hilary had not been too excited by the vigour of her own denunciation to notice Margaret's expression, she might have been bewildered by the look of very decided relief which succeeded to the one of startled dismay with which Margaret had listened to the beginning of her speech. What Hilary had discovered, or fancied she had discovered, really did not matter as long as her secret and Eleanor's was safe.

"Please give me that case at once," she said; "I am afraid, if you wave it about like that, you will drop it, and I value it very much. You had no right to come into my room and meddle with my things, and poke and pry in all my drawers."

"Meddle, and poke, and pry! How dare you use such words to me?" cried Hilary, all the more furiously because the objectionable words contained a sting of truth. "And your things, indeed! I suppose you will say next that this is your necklace and your miniature?"

"Certainly I will," said Margaret with spirit, and without seeing at first whither this admission would lead her. "That is a miniature of my mother; and if you will read the inscription you will see that she gave it to me."

"A fine story," said Hilary contemptuously; "only your name doesn't happen to be Margaret, nor does your surname begin with an 'A.' Ah! you forget that, I think, when you said that your mother gave it to you."

Truly, Margaret had forgotten that, and she met Hilary's triumphant gaze with an expression akin to dismay. She had got herself suddenly into an awkward corner. If she persisted in saying that the miniature and pearls were hers, Hilary would find out that she was passing under an assumed name; whereas, on the other hand, if she did not assert her ownership of them, she would lay herself open to the charge that she had stolen them. It was a perplexing situation, and she hardly knew whether to be relieved or not, when she found, as she speedily did, that Hilary had quite made up her mind that she was a thief.

"You are discovered, I tell you," said Hilary. "I know you belong to the gang of burglars that have been robbing people's houses here during the last six weeks. Come into the dressing-room, and you will see how useless it is to brazen matters out like this."

The fact that Margaret was totally unprepared to see her trunk, that she believed to be empty and pushed away beneath the bed, standing out in the middle of the room, half full of silver, had of course been anticipated by Hilary, who enjoyed her surprise to the full. But the anger that was mingled with Miss Carson's astonishment was, of course, a sham, and Hilary treated it with the contempt she was so convinced that it deserved.

"Did you put all those things in my trunk?" Margaret said indignantly. "What does it mean? Those are the things that were stolen from Colonel Baker's house. I recognise the description of the Indian tablecloth."

"Of course you do," said Hilary with a sneer, "seeing that you stole it to wrap the things in, thief and burglar that you are!"

"Do you really mean that you seriously believe I am a burglar?" Margaret said, and, to Hilary's intense disgust, who felt that this flippant conduct robbed her in some way of her triumph, she went off into a perfect peal of laughter.

"Oh, you are too funny! And do you think that I broke into Walker's shop, too, and also carried off the actress's jewels?"

"Oh, you may laugh if you like," said Hilary furiously. She would have liked to have seen Margaret tremble before her as a criminal should tremble, but she supposed she was too hardened. "But it is a joke that will land you in prison to-night. I am now going down to tell mother all about the sort of person we have in the house, and so that you shan't escape before the police come to take you, I am going to lock you in here."

And almost before the last words had left her lips Hilary whisked herself dexterously out of the room, and slammed the door after her. Margaret heard her locking the door of the bedroom as she passed it on her way downstairs. Margaret's mixture of feelings at this treatment was so curious that at first she could neither laugh nor be angry. She was too angry to laugh, and too amused to be angry. When, however, she walked into her bedroom and saw how thoroughly Hilary had turned over every one of her possessions, leaving them either in a rumpled state in the drawers, or scattered on the floor, indignation triumphed over amusement.

Hilary's charges, too, absurd though, of course, they were, had been brought against her in all seriousness, and Margaret's rising anger made her feel that she must be made to retract them immediately. She found, on going first to one door and then to the other, that though the door of her bedroom was locked, that of the dressing-room was not; for Hilary, finding after she had slammed the door that the key was on the inside, had been obliged to leave it unlocked rather than risk a struggle, for she had been doubtful whether Miss Carson would have permitted herself to be locked in had the swiftness of the action not taken her by surprise.

As Margaret went downstairs she heard Hilary's voice talking fast and eagerly in the drawing-room. She had had five or six minutes start to tell her tale in, and a good deal can be said in five or six minutes, provided that the listener does not hinder the narrator by interruptions. And Mrs. Danvers had not once interrupted, and Hilary had therefore been able to make such good use of her time that she had given her mother a full and complete account of the way in which her first suspicions that there was something mysterious about Miss Carson had gradually grown into a certainty, as clue after clue came into her hands, until this afternoon, by finding all Colonel Baker's stolen property locked away in a box under her bed, she had actually proved her to be a member of the notorious gang of burglars.

Mrs. Danvers' knitting had long ago dropped on to her lap, her ball of wool had rolled unheeded under a chair, and her eyes, round with incredulity and dismay, had been fixed unblinkingly upon her daughter.

"In a box under her bed! All Colonel Baker's things!" she gasped. "Oh, Hilary! and you mean to say that you actually found them there?"

"Yes, every one of them, not half an hour ago," returned Hilary complacently. "And what is more, hidden away in her drawer, I found this." And she opened the case and displayed the necklace and miniature to her mother. "She doesn't attempt to claim Colonel Baker's things as her own, but she persists in saying that this is hers. And considering the inscription, 'To my daughter Margaret,' that is written on it, it is rather silly of her. Without doubt," Hilary added, "it belongs to Miss Cora Anatolia, the Bulgarian dancer."

"But her name doesn't begin with an 'M,' either," said Mrs. Danvers.

"Oh, actresses have lots of names," Hilary said impatiently. "That's not a point we need consider. The point is that whoever it belongs to, it is not Miss Carson's."

And it was at that moment that Margaret, still wearing the hat and the rainproof coat that she had donned to go into the town, entered the drawing-room. She carried her head high, and walked straight down the long drawing-room to Mrs. Danvers' side.

"Your daughter Hilary has been telling you that I am a thief and a burglar, hasn't she?" she said, "and I have come to ask you if you believe her."

Mrs. Danvers shifted uneasily in her chair. There was nothing she disliked more than anything approaching a dispute, and really, when she looked up at the slim, pale girl standing before her it seemed quite too ridiculous to believe, as she had been inclined a moment before to do, that she was a member of a desperate gang of burglars. Hilary was quick to notice her mother's wavering manner, and intervened quickly.

"Then how do you account for all Colonel Baker's things being found locked up in your box?" she exclaimed quickly. "Tell me that."

"I have already told you that I know nothing at all about them. I unpacked my box when I came, and Collins put it away under my bed, and I have never opened it or looked at it since."

There was such an air of sincerity in her voice, that Mrs. Danvers veered round to her side once more.

"There, my dear," she said to Hilary, "you hear what Miss Carson said. She knows nothing whatever about Colonel Baker's things."

"Oh, of course, she would say anything to clear herself," said Hilary angrily. "Don't be so weak as to listen to her, mother. Let her explain how they were found in her box, then. And let her, while she is about it, too, explain how she claims this necklace as her own. Is it the sort of necklace that a holiday governess would own? It must be worth several hundreds of pounds at least. I found it locked up in her dressing bag, and hadn't she happened to leave the key which, as a rule, she is always careful to carry about with her, lying on her dressing table, I could not have got at it."

"Oh, Hilary!" said Mrs. Danvers feebly, "I don't think it was nice of you to poke and pry about in her room, I really don't."

"That is what I told her," said Margaret coldly and contemptuously. "She first of all invented an errand that took me out of the house, and then used the opportunity to search my room."

"Detectives have to do things of that sort," said Hilary, reddening in spite of herself; "but that's not the point. The point is that she says this necklace belongs to her, that the miniature inside the locket is one of her mother who gave it to her. Now, seeing that her name is Eleanor Carson, and not Margaret or a surname beginning with an 'A.,' it is plain enough to any one that she is telling a lie."

"Oh dear!" said Mrs. Danvers feebly, feeling quite unequal to cope with the gravity of the situation, "I wish you both would not quarrel like this, Hilary; you talk so fast that you bewilder me. Now, Miss Carson, it is your turn to speak. I am quite sure that you can explain everything if you will. You are too young, and—and far too nice a girl to be a burglar, and if you will only tell us how Colonel Baker's things got under your bed, I am sure Hilary will gladly apologise for anything she may have said to hurt your feelings. And—and I am sure, as you are so young, and this must be your first offence, that Colonel Baker will not be too hard on you."

"Then you do believe I am a thief!" Margaret exclaimed, staring almost incredulously at Mrs. Danvers. Then without another word she turned abruptly on her heel, and walked towards the door. As she went her foot caught in Mrs. Danver's ball of pink wool; she picked it up, replaced it on Mrs. Danvers' lap, and in another minute was gone from the room. The little action, which was one that she had performed a dozen times a day for Mrs. Danvers since she had been in the house, was sufficient to cause that hapless lady to change her mind again about the character of her holiday governess.

"Oh, no, my dear!" she called out, "I don't, indeed, I don't!"

There was no answer, for Margaret had already shut the door behind her. Mrs. Danvers turned to Hilary:—

"It is all a pack of rubbish that you have been telling me," she said angrily, scarcely knowing what she was saying. "I don't believe a word of it!"

"Just because she picked up your ball of wool!" Hilary exclaimed, with a disdain which, though neither dutiful nor polite, was perhaps not altogether unmerited. "Really, mother!"

Meanwhile Margaret, with anger burning hot within her, had walked straight out of the house. Nothing, she told herself passionately, should induce her to stay a moment longer within it, or ever to enter it again.

Where she was going, or what she was going to do she did not stop to think. The sole idea that possessed her was to get as far away from The Cedars as quickly as she could. Never again, she told herself passionately, would she see or speak to one of the Danvers again. And just as she had come to that resolution she ran full tilt into all of them.

By that time dusk had fallen, and the fog which was coming on thicker than ever, made it almost impossible for any one to see where they were going, so that as she turned a corner of the road which they were approaching from the other direction, she was in the middle of them before she was aware of it. The three girls had met the boys on the parade, and had walked up with them.

"Whither away in such a hurry, Miss Carson?" said Geoffrey, who was the first to recognise her by the light of the street lamp, close to which the encounter took place.

"Ask your mother—ask Hilary," Margaret cried bitterly, and breaking away from him, as he would have detained her, darted across the road, and was immediately swallowed up by the fog.

"Something has happened; she mustn't go like that!" cried Geoffrey, starting after her. But Margaret's movement away from them all had been so sudden and so quick that he could find no trace of her in the dense fog, and realising the hopelessness of pursuit he returned in rather a perturbed frame of mind to the others who were waiting for him by the lamp.

"She was in a right, royal rage," said Maud. "I have never seen Miss Carson angry before. I really didn't know she had it in her."

"Perhaps Hilary has sent her on another message," suggested Nancy.

"Hardly at this hour of the evening," said Edward. "It must be nearly half-past six."

So wondering and speculating as to what could have happened during their absence, but never coming near the truth, they all hurried home as fast as they could, and made their way at once to the drawing-room, where their mother was sitting, looking very helpless and unhappy, while Hilary, with a complacent expression on her face, was telling her all over again of the many and varied clues which had caused her to discover in the person of Miss Carson one of the gang of the Seabourne burglars.

"Why, mother, what is up with Miss Carson?" said Geoffrey at once. "We met her a minute ago running down the road as hard as she could go."

"Running down the road!" echoed Mrs. Danvers. "There, Hilary!" she added, turning to her. "I told you I heard her going out of the hall door, and you said you heard her going upstairs."

"What!" exclaimed Hilary, disregarding her mother altogether. "Miss Carson has escaped! She ought to be brought back. Oh, Geoffrey, why didn't you catch her!"

"I tried to stop her, but she had gone like a flash. But why do you talk about her escaping and of catching her. She isn't a criminal fleeing from justice, is she?"

"But that is just what she is?" cried Hilary triumphantly. "Oh, you have all been finely taken in by her; but I suspected her from the first, and to-night, I have proved her to be a thief and a burglar. I, alone and unaided, have brought her to justice."

"Miss Carson a thief and a burglar!" cried Geoffrey when his astonishment would allow him to speak. "What mad idea have you got into your head now, Hilary?"

Hilary would dearly have liked to have told the long history of the growth of her suspicions about Miss Carson from the very beginning, but knowing that she could not expect the same patient attention from her brothers and sister as her mother had given her, she came straight to the point at once. After all, she was not sure that it was not the most dramatic way of telling her tale.

"I have got no mad idea as you call it, Geoffrey, in my head at all," she said with dignity. "I have merely found out who the Seabourne burglars are, that's all. At least, I have put my hand on one of them, and that one is Miss Carson. This afternoon, locked up in her trunk in the dressing-room upstairs, I found all Colonel Baker's plate and other valuable things."

"Rot!" exclaimed Geoffrey incredulously.

"It isn't rot at all," said Hilary nonchalantly; "it's the truth. But when I taxed her with the crime she denied it."

"Well, of course she did," said Geoffrey. "Of all the nonsense I ever heard this is about the greatest."

Hilary shrugged her shoulders. "Call it nonsense if you like," she said, "but there are the things themselves, every one of them, even to the Indian tablecloth she carried them off in, upstairs in her box at this moment. Go and see them for yourselves if you don't believe me. And if she didn't put them there, who did? Pray tell me that."

Noel looked at Jack, and Jack looked back at Noel. Then they sighed. The moment for confession had undoubtedly arrived, and they both took a step forward.

"We put them there," they said together.

"You!" exclaimed simultaneously every voice in the room except Hilary's, and she was too utterly dumbfounded even to utter that monosyllable.

"It was a joke," said Noel. "Tommy started it really. It was his idea, and he got us to hide the whole of the beastly things here. I am sure we wish we had never seen them. Of course we didn't know the trunk belonged to Miss Carson, or we wouldn't have hidden them in it. We thought it was an old one of mother's that was never used. We would have taken them back to Colonel Baker ages ago, only Tommy, the young idiot! chose to go off to Scotland and took the key with him. We couldn't open the trunk anyhow, though we tried ever so many keys."

"Oh boys, boys!" moaned Mrs. Danvers, "a nice mess you have got yourselves into. The Colonel will be furious. You have made him the laughing stock of the town. He will certainly summons you, and it will get into the papers, and you will certainly be expelled from Osborne and Dartmouth."

"And serve them right too, for a couple of silly young asses!" growled Geoffrey.

"That is all very well," said Hilary, swallowing her intense mortification as well as she could; "but what about this case?" opening it and displaying as she spoke the locket encircled by the string of pearls. "I found it locked up in her dressing bag, and she declares it is hers, although 'To my daughter Margaret' is inscribed inside the locket."

But Geoffrey would not as much as glance at it.

"I think you have behaved disgracefully," he said, turning upon his sister, "and ought to be thoroughly ashamed of yourself. The idea of going prying about in her room."

"I did it in a good cause," said Hilary, who, fully conscious now of the sorry figure she cut, had much ado to keep tears of mortification and rage from coming into her eyes. "How was I to know that the boys had put them into her box and not she herself? It's as much their fault as mine that Miss Carson got accused of taking them."

"Oh, oh, Miss Hilary!" said Edward, "that's rather good from one who not five minutes ago was boasting of having alone and unaided—those were your exact words, I think—brought the criminal to justice."

Hilary winced. She knew that for weeks, perhaps months to come, her brief and inglorious career as a detective would be one of the stock jokes of the family, and the thought of all the chaff she would have to endure was anything but pleasing to her.

"Never mind whose fault it is," said Geoffrey with a touch of impatience in his voice, "what does that matter now? The point is that a girl staying in our house has been terribly insulted and practically driven out of it, and she ought to be found and persuaded to come back, when the first thing you will do, Miss," turning to Hilary, "will be to make her the most abject apology you ever made to any one in all your born days."

"She'll come back of her own accord, surely, by dinner-time," said Mrs. Danvers uneasily.

"Don't you believe it, mother," Geoffrey said emphatically. "When we met Miss Carson just now the very last thought she had in her mind was the intention of ever darkening our doors again."

At that moment Martin opened the drawing-room door. They had all been so intent upon the conversation that was taking place that none of them had heard the sound of wheels upon the gravel a few minutes previously, consequently they were all taken by surprise to see two strangers behind Martin.

"Mr. Anstruther and Miss Eleanor Carson," Martin said, and a tall and thin old man with a long white beard, and a girl who none of them had ever seen before, advanced into the room.