Despite the fact that Sue and Carol boiled with impatience for over a week, conjecturing what it could possibly be that made Louis afraid of the picture in Monsieur's room, they found out nothing new on the subject, for the simple reason that there was never a moment when they again saw him alone. To ask him about it when others were in the room was impossible. Two days after Sue's last visit he was allowed to sit up, and a day or two after that he was permitted to walk about for a few steps. Then the nurse took her leave, and Louis insisted on returning to his own room on the ground floor.

"And only to think," sighed Sue, when she heard of it, "now we'll probably never see those strange pictures on Monsieur's wall again. I could cry with vexation when I think of it. Carol, do you feel as if there were something terribly mysterious about them,—not only the two covered ones, but the boy's, also? I wonder if it haunts you the same as it does me?"

"It certainly does," admitted Carol, "and yesterday I wrote a little poem about it. Here it is. What do you think of it?"

She handed Sue a scrap of paper on which the verses were written. The two girls had dropped off the trolley on their way home from high school, and were bound for the library. Sue took the paper and studied it carefully as she walked.

"I like it a lot," she acknowledged, as she handed it back. "Especially those last two lines:

Really, it's awfully pretty and the best thing you've done yet. Why don't you show it to Miss Cullingford. It hasn't any direct reference to Louis's affairs in it, and I'll warrant she'd recommend it to be published in our high school paper, The Argus."

"Well, perhaps I will," agreed Carol, visibly pleased with Sue's unstinted praise. She folded the paper back into a book as they went up the steps of the library.

It was while the two were wandering round the big, sunny room, scanning the shelves for an interesting book, that they made a startling discovery.

"Will you look at that!" whispered Carol, suddenly pinching Sue as they were passing the door of the smaller reference room, a spot they themselves seldom entered. There, near a shelf of immense volumes, stood—who but the Imp! She was deeply engrossed in the pages of a tome nearly as large as herself. The sight was the more amazing because the Imp was neither a member of the library, so far as they knew, nor did she ever enter it, if she could help it, except rarely to get a book for the girls.

The two stood rooted to the spot with astonishment. Suddenly the Imp caught sight of them. She promptly closed the book and slipped it back on the shelf. All she would admit in reply to what she felt to be their intrusive inquiries was the statement:

"I'm looking up something on the advice of Miss Hastings. I guess I don't have to explain everything to you." After which remark she marched majestically out of the room.

The girls tried to guess from the shelf where she had stood what book she had been consulting, but as it was a long row of encyclopedias, all exactly alike, they could not glean the least inkling. Giving up that course, they questioned the librarian on the way out, and found that the Imp had joined the library several days before.

"Did you ever know anything to beat it?" demanded Sue, as they passed down the steps. "What can she be up to? I know she's awfully bright and reads lots of books that interest grown-folks, but she's so lazy about things and so crazy just to be outdoors that she never thought it worth while to join the library before."

"She said," Carol reminded her, "that her teacher, Miss Hastings, advised her to look up something. You know she always tells the truth, at least."

"That's true," admitted Sue, "but it must be something out of the ordinary, or she would simply have come to us and bribed us to go and do it for her. And besides, in her class they don't have to look up things in encyclopedias; they haven't got to that yet. No, I'm certain it's something else."

Wondering about the Imp's strange behavior, they harked back, as they walked homeward, to that other subject that was constantly puzzling them.

"Do you know," said Carol, "I believe that I've come to agree with you in your theory about Louis and Monsieur. You know I didn't when you first told me, because I was awfully disappointed about his not being a count or a duke. But now I think that you're right. Monsieur is probably the family lawyer, and Louis is going to inherit a big French fortune. But if that is the case, why is it that Monsieur seems to be trying so hard to make Louis like him? You remember, Louis said the other day that he constantly feels as if Monsieur were doing everything in his power to win his affection, for some reason or other. If he were only a family lawyer, he wouldn't care a penny whether Louis liked him or not. And why was he kissing his hand the other day? I'm half-inclined to believe that he's some relative—a grandfather or an uncle or something. Yet he could scarcely be that, and the lawyer, too. Isn't it a puzzle?"

"But don't you remember that Miss Yvonne told Louis he wasn't any relative?" Sue reminded her; "only an old friend of the family."

"Susette," remarked Carol solemnly, stopping stock still in the middle of the road, "you may call me all kinds of an idiot if you like, but I want to tell you one thing. I've been feeling lately that there's some mystery here, bigger than anything you or I imagine. It's just a feeling I have, but it haunts me continually. I'm certain something is going to happen that will make us gasp with astonishment. And when that does happen, I want you to remind me of what I've said to-day. I'm sure I'm right. I feel it in my very bones, as Aunt Agatha often says."

And Sue, much impressed, as solemnly promised to remind her.

March 27. There's something that the Imp is up to,—something that she has discovered. I'm as certain of it as I am that my name is Susette Birdsey. The reason I know this is because of what happened to-day.

Carol and I had gone down this afternoon to Anita Brown's to go over some English history with her for an exam we're going to have in a day or two. Anita is great on history, and somehow can make it seem so simple and sensible and easy to remember. I don't know how she does it, but we always like to study that subject with her and get her to explain all about the succession of kings and what relation they were to each other. She has the knack of making them seem like real people.

Well, we had stopped at her house on the way from high school, so we hadn't been home this afternoon. About half-past four we left, and happened to come out of her gate just a little behind two people who were walking up the road. (Anita lives about half-way between our house and the village.) It didn't take us an instant to recognize those two people as Monsieur and the Imp. Carol was all for hurrying along to join them, but I said no, we might just as well keep to ourselves, for they probably didn't care for our company, anyway. So we kept on behind them, and they were talking so fast and hard that they didn't even notice us.

Presently the Imp did a queer thing. She opened her school-bag, took out a book—it wasn't a school-book, either!—opened it at a certain page, and showed something to Monsieur. Whatever it was, it had the strangest effect on him. He gave one look at the page, then stopped stock still in the road and stared at the Imp, making a queer sound in his throat, as if he were trying to clear it and didn't succeed very well. Then he said something in French that we caught the sound of but couldn't understand. But the Imp was evidently so excited that she forgot to speak French, for we heard her say in English:

"Then I'm right, Monsieur? It's the same? I was sure it was."

And he answered:

"Oui, oui, petite mademoiselle!" (I know enough French to translate this as "Yes, yes.")

After that the Imp went right on to chatter in French. But by this time we'd made up our minds that it was high time we were let in to that little secret, so we hurried to catch up with them. But the Imp saw us too quickly. She shut the book, slipped it back in her school-bag, and by the time we had joined them they were conversing sedately in English about the weather.

When we reached our own gate the Imp went off about her own devices, with never a word about the queer performance on the street. But Carol and I made up our mind that we'd take a peep at that book in her school-bag when she wasn't around. So when she had gone upstairs for a while, we opened the school-bag that she had flung down on the couch in the living-room.

But when did we ever manage to get ahead of the Imp? She had carefully removed that book, and it was nowhere to be found. I remember noticing that it was a thick book with a light green cover, and there was nothing even faintly resembling it anywhere about, so far as we could discover. What she could have done with it, or when she could have taken it out without our notice, beats me. Leave it to the Imp, however, to accomplish that sort of trick.

Of course we plainly saw that there was nothing we could do, except to question her, and we debated the longest time about whether to do so or not. It's such a hopeless performance, if the Imp has made up her mind beforehand that you're not going to find out anything from her. Carol suggested that we ask her right out what she had discovered that Monsieur was so interested in. I told her there was only one kind of answer to expect to that, so what on earth was the use?

I thought I had a better scheme. The Imp has been wild for a long time to have a fountain-pen like the one I bought in Bridgeton two months ago for a dollar. I was going to save up and give her one for her birthday. But that's a long way off yet. So I suggested to Carol that I offer to let the Imp have mine, and then buy a new one with the dollar Uncle Ben gave me at Christmas. She said it was an awful waste of a good pen, and might not accomplish what we wanted, anyway, but that I could try it if I liked.

So a little later, when the Imp came in where we were studying, I began on the subject, but very carefully, so that she wouldn't suspect something right at the start and spoil everything. After she had settled herself to read—it was my book, by the way!—I began thus:

"You and Monsieur seemed to be having a nice time while you were coming up the road this afternoon. Does he think you talk good French?"

The Imp glanced at me warily, but replied in an amiable manner:

"Oh, yes. He says I'm the only person he's met in America, except Louis and his folks, who speaks it with a decent accent."

Then she went on reading. It was plain that she wasn't going to give us any opening, if she could help it.

"Do you always talk to him in French?" I went on cautiously.

"Yes, always. He likes it best," she answered, without looking up again.

"But we heard you say something to him in English this afternoon," I ventured, for I had a scheme as to just how I was going to trap her. For a wonder, she fell into it.

"I didn't! I don't remember saying a word in English."

This was just what I had thought. She was so excited at the time that she hadn't remembered.

"Oh, but you did!" broke in Carol. "We heard you say: 'Then I'm right? It is the same? I was sure it was.'"

"You horrid things!" burst out the Imp. "Always tracking me around and eavesdropping! You once accused me of that, but I think the tables are turned now."

"Look here," I said, and I felt downright mad, "you know perfectly well we weren't doing anything of the kind. We happened to come out of Anita's house right behind you, and we refrained from joining you at first because we knew you didn't want us. We couldn't help it if you talked so loud that we could hear what you said."

She calmed down at that, and I seized the advantage and determined on a bold stroke.

"Bobs dear," I said, in as friendly a way as I could, "we know you've discovered something about Monsieur or Louis or some one from what you said and did this afternoon. Won't you tell us about it, too? You know we're awfully interested. And just to show you that we only mean to be friendly, I'll give you that new fountain-pen of mine, if you care to have it. I don't mean it as a bribe, but only to make you feel that we aren't really hateful."

At this her eyes fairly sparkled for a moment. Then she shook her head.

"I can't do it, girls, much as I'm crazy to have that pen. Honest, I can't. I'm not teasing you about it this time, either. I really have discovered something quite important, and it just happened by accident, too. But Monsieur was so upset about it, and asked me so politely not to say anything to any one, that I just feel it wouldn't be right. I think I took him terribly by surprise. I don't know what it all means yet myself. There's something awfully mysterious about things over at Louis's. And really, you've been so decent to me lately that I'd tell you if I could, even without the pen."

Well, that was too much for me. I knew she meant every word she said, and I could understand, too, why she felt she couldn't tell us. So I just gave her the pen, anyway, and she was so happy and grateful. She said:

"It's all right, girls. You're trumps! And I'll do something for you yet, never you fear."

But only to think that it was the Imp who made the first real, important discovery about this mystery! Well, things do happen queerly. I wonder what in the world she can have discovered?