The two girls rushed into the empty room and examined every corner minutely. There was not a trace of any secret exit to be found. The opening through which Mrs. Wilson must have disappeared was evidently marvellously well concealed.

"Where can she be? It's like magic!" whispered Cicely.

"Wherever she's gone, I suppose she'll have to come back," replied Lindsay.

"Listen!" said Cicely, with a start.

It was the same strange sound again which they had heard on their former expedition—a low, long-drawn-out moaning, as of someone in pain, feeble at first, then growing louder, and suddenly ceasing.

"Oh! I wonder if she's hurting anybody?" cried Cicely, shuddering with horror.

"I'd give a great deal to find out what's going on. I'm afraid it's something that won't bear the light of day," said Lindsay uneasily.

"Dare we wait till she comes out of her hiding-place?"

"Yes, but we mustn't stay here. It would spoil everything if she caught us. Let us go outside and close the door again, and watch through the keyhole; then, if we see her coming, we can rush."

Mrs. Wilson's errand was evidently a long one. Though they relieved each other more than once in mounting guard over the keyhole, she did not return.

"Perhaps she knows we're here, and won't come out till we've gone," suggested Lindsay at last.

"How could she know?"

"She may have been looking at us all the time through some little spy place."

"Oh, how horrid! It makes me feel quite creepy to think of it."

The fact that they were doing exactly the same did not strike either of the girls. Circumstances alter cases, and they considered they were justified in their plan of action. They grew extremely tired of waiting, but they were determined not to give in.

"There's that noise again!" said Cicely. "She must have a prisoner shut up there; I'm perfectly certain about it."

Both put their ears to the door, and were so absorbed in listening to the queer sounds inside the room that they did not hear footsteps sounding up the winding staircase. An exclamation behind them caused them to turn hastily round.

There was Monica!—the last person in the world whom they had expected to see, and who was looking as astonished as themselves at the meeting. Lindsay and Cicely felt decidedly embarrassed. Monica must have seen them peeping through the keyhole, and they knew they had been discovered in a somewhat doubtful and discreditable occupation. They could not possibly begin to explain that it was entirely on her account and for her benefit, so they simply turned very red and said nothing. It was a most uncomfortable situation.

There was a painful pause, and then Monica recovered her presence of mind.

"Why, Lindsay and Cicely, I thought you were with the others in the garden!" she said.

"We were only exploring the house a little," replied Lindsay, trying to pass the matter off carelessly. "Miss Russell said there were interesting things all over it."

"I'm afraid you won't find much to interest you among empty bedrooms," said Monica, in her calm, quiet voice. "If you like to come downstairs with me I'll show you some of the curiosities in my cabinet. I've a great many old coins and a few daggers that were dug up when the moat was drained."

Looking rather shamefaced, the pair went with Monica to the library, where she unlocked an oak cupboard, and spent quite twenty minutes in explaining her various treasures. She was most kind, and spared no trouble, but the others could not get over their confusion. They had the guilty sensation that they had been caught like naughty children, and were being amused to keep them out of the way.

"Why was Monica going into the lantern room?" demanded Lindsay, the moment they were alone.

"Does she know the secret?" ventured Cicely.

"Either she knows, or she's trying to find out. Perhaps she's stalking Mrs. Wilson too!"

This was a new idea, and required consideration.

"Then that would perhaps be what 'The Griffin' was warning Scott about," said Cicely reflectively. "Ought we to tell Monica?"

"Not yet—not till we've something more definite to go upon. We've only suspicions at present, and one can hardly speak about those. She might be offended, and think us meddlesome, especially as she doesn't like to talk of her affairs."

"I'm afraid she'll think us sneaky and underhand, in any case. I'm so sorry she saw us spying like that."

"Well, we couldn't help it, and we can't explain."

"Mightn't we just say why——?"

"It's no use," interrupted Lindsay decidedly. "We'd better not breathe a word."

And Cicely, as usual, gave way.

It was gratifying to feel that they were Monica's champions, though she might not yet be aware of what she owed them. They must be content to be misunderstood for a little while; afterwards she would appreciate what they had been doing for her, and would thank them accordingly. They often looked at her in school with the satisfactory sensation that they knew something of which everyone else, even Miss Russell, was ignorant.

I fear the lessons suffered sometimes while they indulged in day-dreams, for it was hard to recall such mundane matters as the capital of Mexico, or the date of Magna Charta, when their thoughts were far away in the lantern room, busy with concealed prisoners or supposed plots.

"You're the two most inattentive girls in the class!" cried Miss Frazer indignantly one day, after a specially bad lapse of memory. "You both did far better at Winterburn Lodge. I cannot understand why your work should have fallen off so much lately. This is the third time this week you have had bad marks. If it occurs again, I shall be obliged to report you to Miss Russell."

Apart from their interest in her as the owner of the hidden treasure, Lindsay and Cicely regarded Monica with the worship which schoolgirls are sometimes fond of bestowing upon a companion who happens specially to attract them. They admired the shape of her nose and her long chestnut hair, and considered her dignified manner absolute perfection. They used to follow her about at a respectful distance, longing to improve the acquaintance; but they received so many snubs from the elder girls, who also wished to monopolize her, that matters did not advance much further than an occasional "Good morning" or "Good afternoon".

"The big ones are so jealous, they like to keep her all to themselves," grumbled Cicely. "Eleanor Wright was quite rude when I offered to lend Monica a pencil yesterday. She said I was 'officious'."

"They're horribly mean," agreed Lindsay.

Monica had certainly become a great favourite at the Manor with both teachers and pupils, and, had she been of a less steady disposition, might have run considerable danger of being spoilt. She took her sudden popularity, however, very serenely, and scarcely seemed to notice that her schoolfellows were quarrelling over who should sit next her in class, or take part with her in a game of tennis.

"She always seems so calm and superior, like a nightingale among sparrows," remarked Irene Spencer sentimentally.

"Or a swan among a flock of geese," laughed Mildred Roper. "You've all grown really quite silly over Monica. I admire her very much myself, but I don't go and kiss her jacket when it's hanging in the vestibule, or beg her old torn exercises for keepsakes."

"Oh, well, you're a monitress!"

"I've got a little common sense left, I'm thankful to say."

The pretty rose-covered cottage where Monica and her mother had established themselves for the summer was only a few minutes' walk away from the Manor. One afternoon Miss Russell, happening to meet Lindsay and Cicely in the hall, gave them a note, and told them to take it at once to Mrs. Courtenay, and bring back an answer.

The two girls ran off in high glee, delighted to have this opportunity of seeing their idol in private. They found Monica preparing her French lesson in the small strip of front garden, but she put her books aside as they opened the gate.

"Come to Mother," she said, when they had explained their errand, leading the way through a French window into a low, old-fashioned sitting-room.

Mrs. Courtenay was a sweet, delicate-looking lady, with a gentle, refined face, and hair slightly streaked with grey. She did not rise from her sofa when they entered, but held out her hand instead, and asked them to come and speak to her.

"I am somewhat of an invalid, you see," she said. "The doctor is very strict, and has told me to lie still. It's rather hard, but I am trying to obey. So you are two of Monica's little friends? Well, now you are here, you had better stay for tea. The letter? Oh, I'll send Jenny, our maid, with the answer, and she shall tell Miss Russell that I'm keeping you. We'll take care that you go back in plenty of time for preparation."

This was indeed a most unexpected treat. Both Lindsay and Cicely beamed with smiles. They were the only girls in the school who had been thus favoured, and they felt that their present enjoyment would be equalled by the envy which they would excite among the others on their return.

"I am glad to hear you are all so happy at the Manor," continued Mrs. Courtenay. "Isn't it a dear, interesting old place? I expect Monica will have told you most of the legends. No! Why, Monica, what have you been thinking of? Do you mean to say they haven't heard yet about your ancestress and Sir Humphrey Warden in the rose avenue?"

"There really hasn't been any time for telling stories, Mother," declared Monica, "we've been so busy playing tennis when we were not at lessons. I'm never very good at remembering them, either—not like you are."

"I suppose I must consider myself the family chronicler," said Mrs. Courtenay. "We certainly ought to let Lindsay and Cicely hear the tale of the picture. Ah, here comes tea! Monica, you must look after our guests."

Monica evidently loved to be her mother's nurse. She placed a small table by the side of the sofa, and busied herself in arranging cushions and seeing that everything was placed for the invalid's greatest comfort. She did not neglect the visitors either, and brought out a jar of honey for their special benefit.

"I know you'll like it, because you were so interested in the bees," she said. "Do you remember the day when you went too close to the hives, and nearly got stung?"

"Yes; we had to run the whole length of the walk where the roses grow. I shan't forget it in a hurry," answered Cicely.

"That is the rose avenue where my namesake outwitted Sir Humphrey Warden. I wish you would tell them the story, Mother."

"Oh, do, please," pleaded Lindsay and Cicely; "we'd like so immensely to hear it!"

"I believe I shall just have time while we finish tea," said Mrs. Courtenay. "I suppose you need not be back in school until half-past five? Have you been in the long gallery at the Manor, and looked at the pictures?"

"Yes, often," said Cicely.

"Then you will remember one, at the far end, of a girl in a white dress, holding a bunch of roses in her hand?"

"Yes; it's the prettiest of them all. We always say it's the exact image of Monica."

"It is the portrait of a Monica Courtenay who lived here in the time of the Civil War. Her father was killed fighting for the king at Marston Moor, and her only brother, Sir Piers, was also one of the hottest supporters of the crown. When Cromwell came into power, Sir Piers had to flee for his life. He was chased from one hiding-place to another. Sometimes, like Prince Charles, he had to clamber up a tree until the soldiers had passed by, and once he spent a night in a fox's hole.

"At length, one summer evening, hunted almost to desperation, he returned to his old home. He met his sister in the garden, and though she exclaimed with joy at seeing him, she immediately made a sign for silence, and motioned him to conceal himself under a large box tree which stood near.

"It was not safe, so she whispered, to go to the Manor. There were spies about, and Sir Humphrey Warden, the most zealous Roundhead in the district, had set a watch upon the house. At any moment they expected he might arrive with a troop of soldiers. Piers must stay where he was, and she would run and bring him the key of the boathouse; then, under cover of the darkness, he might creep away to the river, get out the boat, and drop with the current until he reached the sea, where possibly he might find a ship to take him over to France.

"She hurried indoors at once to fetch the small key that unlocked the boathouse, but as she was returning down the avenue she found she was just too late. There was a tramp of horses' hoofs, and Sir Humphrey Warden came riding up at the head of a band of men.

"'Good even, fair neighbour,' he said. 'I must needs make an inspection of your house, and with your permission I will give myself the honour of supping with you to-night. What brings you hither?'

"'I do but take the air, and pluck a few of these fragrant blossoms,' replied Monica hastily. 'I will presently conduct you to the Manor myself, and entertain you.'

"She was in a desperate strait. How could she manage to save her brother? Now that Sir Humphrey had come, she knew her every movement would be watched. No one could be trusted, for the servants (so she feared) had all been bribed. Gathering a bunch of roses, she contrived unnoticed to slip her little key inside the heart of one of them.

"'I would fain crave the favour of a flower, madam,' said Sir Humphrey, who was an admirer of fair dames, in spite of his Puritan dress.

"'Take your choice, sir,' replied Monica, boldly holding out her bunch. 'Nay, not this red one; it is overblown, and will fall directly. 'Tis but fit to be flung away. This pink hath the sweeter scent, an you will wear it for me.'

"As she spoke she tossed the rose containing the key with apparent carelessness over the hedge to the foot of the box tree where her brother was lying concealed; then, leading her unwelcome guest to the house, she gave orders for his due entertainment.

"Sir Humphrey and his men searched the Manor in vain, but they never thought of looking in the garden, where the fugitive was waiting till the darkness should be black enough to hide him. Sir Piers got safely away to France, and returned in triumph to his estates when Charles II came to his own again. As a remembrance of his wonderful escape, he caused his sister's portrait to be painted, with the bunch of roses in her hand. Ever since the Courtenays have had an almost superstitious reverence for the picture. There is an old saying that it guards the safety and fortunes of the family."

"And what became of Monica?" asked Lindsay, who had been deeply interested in the story.

"She married a cavalier friend of her brother's, and went to live in Devonshire. I believe she kept one of the roses treasured away in a box, and it was buried with her when she died."

"I suppose Monica was christened after her?" said Cicely.

"Yes; that has always been a favourite name with the Courtenays, though I do not think any of them can have more closely resembled the portrait."

"How can the picture guard your fortunes?" enquired Lindsay.

"I don't know. It is one of those quaint ideas that sometimes linger in families. Of course it is only a tale, and I am afraid I have been a long while in telling it. Monica, dear, it is twenty minutes past five. Lindsay and Cicely must hurry back to school at once, if they are to be in time for preparation. We shall get into sad disgrace with Miss Russell if we allow them to be late."

"I think your mother is perfectly sweet," said Lindsay, as Monica walked with them along the road to the Manor gates.

"She's just everything in the whole world to me," replied Monica. "I wish she were stronger, though. She has been ill for such a long time. The doctor says it would do her good to spend next winter in the south of Italy, but that, I'm afraid, will be quite impossible. She ought to go, it might make all the difference," she continued, almost as if talking to herself; "yet we can't manage it, however much we try, unless, indeed——"

But here she seemed to recollect the presence of her companions, and wishing them a hasty good-bye, she turned back to the cottage.

"I know what Monica was going to say," remarked Cicely, as they walked up the drive.

"She meant her mother would be able to go away if the treasure were found," replied Lindsay. "Oh! it does seem hard, when they need it so badly, that it should be shut up somewhere, and doing no good to anybody at all."

"I think Monica is frightened lest Mrs. Courtenay should grow worse and die, if they have to stay in England for the winter. I don't believe she would enjoy a penny of her fortune if it were to come too late for her to share it with her mother."