Although Linda and Louise were both greatly excited about their plan, they decided to keep it a secret. Once they disclosed it, they would probably meet with all sorts of opposition; Mr. Carlton would consider it foolish, his sister and Mrs. Haydock, dangerous.

So Linda went home and opened her invitations, accepting those that were scheduled for before Christmas, and took an active interest in her aunt's preparations for the great day. There was a small afternoon bridge at Sue's which she could attend, and a moonlight skating party which Dot had planned for December twenty-third, and of course she could go to the big Christmas Eve dance at the Country Club with Ralph Clavering.

Nor was her father's misfortune mentioned again after her first afternoon at home. Mr. Carlton had apparently made his decisions, and wanted his daughter and his sister to forget his troubles in their enjoyment of the holidays. Everything went on as it had at all other Christmas seasons; even the Arrow remained unmolested in its hangar, and Louise and Linda drove their cars.

It was on one of their shopping tours that they were able to take the first step in carrying out their enterprise. On the twenty-third of December they motored to Columbus and visited the city's largest department store.

Going straight to the linen counter, Louise asked to see a handkerchief like the one Linda was carrying, which she showed to the saleswoman.

"Seven dollars!" she repeated, as she examined it. "I'd have to put it in my trousseau at that rate. And then suppose I never got married!"

"You will," returned Linda, calmly. "But even if you don't, you're sure to be a bridesmaid some time. You could carry it then."

"Your bridesmaid?"

"If I ever need one. Or rather, my maid-of-honor."

The saleswoman coughed irritably; she wanted to hurry the purchase.

"It's the last one we have, Miss," she said. "So if you like it, you had better take it."

Her words recalled to Louise the purpose of their visit.

"The last one? They're hard to get, then?" she inquired.

"Yes. They are made by French women, I believe—in a convent."

Louise suppressed a smile by raising her eyebrows.

"Imported?"

"I think so. We get them through a New York firm."

"What is the name of the firm?" asked Linda, innocently.

"That I don't know. But if you care to wait, I'll ask the buyer."

"Yes," agreed Louise. "I'll take the handkerchief if you find out the name of the firm."

The saleswoman looked rather puzzled at their interest in the name, but she thought they wanted to make sure their purchase was not an imitation, and she hurried off to comply with the request. In a couple of minutes she returned with the information.

"The name is Carwein," she said, as she handed Louise her package. "J. W. Carwein & Co., Importers, New York City."

Linda carefully made note of the fact in her tiny shopping book.

"So our first stop is New York," remarked Louise, as they left the store and went to the garage where they had parked her roadster. "Of course we fly?"

"Naturally. We haven't time for any slower conveyance. Besides, we may need the Arrow for further investigation."

"O. K. But Linda, have you considered snow and sleet? Remember, so far we have had very little experience in cold weather."

"I realize all that. But I've been studying conditions about winter flying, you know, and I have a lot of theory. Of course theory isn't practice, as our friend Miss Hulbert would remind us."

"By the way, where is she? She just seems to have dropped out of existence."

"Probably she has the Club's Moth somewhere, visiting her friends!" replied Linda. "I can't say I miss her. Still, it is funny her brother isn't around. He seemed so devoted to Kitty."

"Maybe he asked Kitty to marry him, and she refused."

"I don't think so. Kitty was so crazy about him at Thanksgiving."

"Well, you never can tell. But that isn't going to worry me," said the other, laughing. "But here is an idea worth taxing your brain with, Linda!"

"Yes."

"I think somebody ought to know just what we're doing, and where we're going, so long as we don't want to give our parents the exact information. It ought to be somebody who could fly to our rescue, if necessary.... I am thinking of Ted Mackay."

Linda nodded, approvingly. Ted was so capable, so dependable, and she knew he would risk his life if need be in an emergency to save them.

"You really think it's necessary?" she asked.

"Maybe not necessary, but prudent. Can't you map out our route to New York tonight, and send him a special-delivery letter? Then we can wire him from New York, if we decide to go on to Canada."

"Yes, that's a fine idea, Lou. Provided, of course, we get Aunt Emily's permission. Daddy leaves Christmas night, and after that I'm under her thumb."

"I'm going to spring it on my family after Christmas dinner," Louise informed her. "Everybody's in such a good humor then, that they probably won't refuse. Besides, we needn't mention Canada. Just say a flying trip."

"I guess I'll do the same thing. And by the way, Lou, let's wire Nancy Bancroft. You know she made us promise to stay with her whenever we flew to New York."

"An excellent plan!" approved her chum, for she liked the girl—a fellow student at the ground school. How much easier it would be to win the older people's permission if they could visit a friend!

Linda, however, did not wish to tell her father about the flight, for fear he might suspect what she was up to, and forbid her. Accordingly, she waited until almost eleven o'clock on Christmas night to ask her aunt's permission. They were together in the library, Linda idly gazing at the brightly lighted tree, Miss Carlton looking over the pile of cards on the table.

"Here's one from Beatrice Evanston," observed the latter. "Did you send her one, Linda?"

"I don't believe I did," replied the girl absently. She tapped her fingers nervously. It was difficult to begin.

"Aunt Emily!" she finally blurted out, "Lou and I are planning to go to New York tomorrow, if you are willing."

"Why of course," replied the other, to her niece's surprise. "But that's a long trip, and if it's shopping, you can do almost as well in Columbus. Or is it a house-party?"

"Neither. Though we are going to stay all night with a girl from school who lives there. But—we're flying."

"Flying? Oh, Linda, please don't! We're in for a snowstorm, I'm perfectly sure. I do wish you would put that plane away for the winter!"

"I can't do that, Aunt Emily. A real pilot has to fly in all kinds of weather. I really need the experience, and the Pursuit is in fine shape."

Suddenly her aunt put down the cards she was fingering and frowned.

"You can't, dear! You'd miss the Evanstons' ball, Beatrice's coming-out party. Why, it's the biggest thing in Spring City—after Kitty's!"

"But I had already declined that invitation," Linda stated coolly.

"You didn't? Oh, Linda, you wouldn't!"

"But I did. The day I got home. Louise and I both did. We wanted to reserve this whole week—between Christmas and New Year's—for ourselves, so we turned down everything."

Miss Carlton looked absolutely aghast.

"I never heard of anything so queer!" she exclaimed. "When you and Louise see each other every day in the year!"

"But this is different. This is a lark together.... Oh, Auntie, please understand! We loved this last week with you and Daddy and our friends, but this is important to us now. You won't be hurt?"

She came over and sat on the arm of her aunt's chair, her eyes full of pleading.

"Oh, all right, dear," agreed the older woman with resignation. "I suppose it's about as useless to try to keep you out of the air as it would be to keep Lindbergh.... I wish your mother hadn't named you Linda!"

Linda laughed, but she knew that she had won, and, even at this late hour she felt that she must call her chum to tell her the good news.

With sandwiches and hot coffee in their lunch box, and clothing enough to last them for a week, the girls took off the following morning. The air was crisp and cold, but it did not snow. Snug in their leather coats and helmets, they felt ready for any weather. The engine was running smoothly; it was a joy to fly, especially now that they could take turns at the controls.

In her pocket Linda carried a map which Ted Mackay had sent to her in reply to her letter, so that she found it easy to follow the course he had indicated. Without the slightest deviation, they arrived at their destination late that afternoon.

Leaving the plane to be housed and inspected, the girls made their way across New York to a hotel in the center of the city, where they sent wires to Ted and Miss Carlton and Mrs. Haydock, and changed into street clothing. Then they looked up the firm of Carwein in the telephone book.

"But what shall we say to him?" asked Linda.

"I don't know," admitted Louise.

Impulsively as they had rushed into this plan, they realized that they hadn't an idea how to proceed.

"Suppose he won't see us!" remarked Louise.

"He probably won't. If we tell the secretary it is private business, she'll think we want to sell him life insurance, or something."

In that strange hotel room, as they sat looking blankly at each other, they knew that they had not thought far enough. Suddenly they were both tired and hungry.

"Let's don't do a thing this afternoon," suggested Louise. "Just call up Nancy Bancroft, and say we'll be out there right away. She's expecting us for dinner, anyhow."

Linda looked immensely relieved.

They found the girl's home without any difficulty, and were welcomed like old friends. Nancy was one of a large family, and the house fairly buzzed with gayety. There were three other guests besides themselves at dinner, and afterwards a dozen more came in for games and for dancing. It was informal and charming; both Linda and Louise would have liked nothing better than to accept Mrs. Bancroft's invitation to stay until school opened. But that would have meant relinquishing their plan, and this they would not do.

In an interval between dances, Louise drew her chum into the sitting-room where Mr. and Mrs. Bancroft were quietly reading, and asked the former to give them some help on a mystery they were trying to solve.

"Do you happen to know a man named J. W. Carwein—an importer and wholesale dealer in fine linens?" she inquired.

"Why, yes, I know the firm," replied Mr. Bancroft. "I don't know him personally. Why?"

"Well, we want to make an investigation—on the quiet, if possible," explained Louise. "We'd like to find out where and how he's getting hold of a certain kind of very fine lace-work. He's practically smashed Linda's father's business, and we're trying to discover how he did it."

"From his reputation, I don't believe Carwein goes in for underhand dealing like that. If he is, he probably has had one put over on him. He sells only the most expensive things, and his firm has always had a good name. He'd probably tell you right out where he buys the goods."

"But how could we see him?" asked Linda. "Girls can't walk right into an office and demand to see the president!"

Mr. Bancroft smiled.

"It's been done," he said. "But I don't think it's necessary. I believe you can get the information you want from his secretary. It isn't likely he'd have anything to hide."

Just as simple as that! The girls could hardly believe it was possible, yet next morning, when they put the advice into effect, they found it good.

The secretary informed them that the goods were _not_ imported, that they were made right here in New York state. An agent by the name of Hofstatter had come into the firm's offices and sold them, assuring Mr. Carwein that they were made by a group of French women in the extreme northern part, near the town of Plattsburg. He said he was a traveling man, and that he would return in three months' time for more orders.

When Louise had repeated this conversation to Linda, they sat looking at each other in despair.

"I'm afraid our trip's been in vain," moaned Louise. "Somebody is imitating the work— somebody right here in New York. Of course they can afford to sell it cheaper than your father—with no tax to pay!"

Linda's eyes narrowed. She was not convinced.

"There's something fishy about the whole thing!" she said. "Because if this man Hofstatter didn't buy from the Convent, who did? They had nothing left to sell to Daddy!"

"Maybe he lied to Carwein!" exclaimed Louise. "Anybody can see that my handkerchief is exactly like yours."

"Yes! I think this man Hofstatter has smuggled the stuff into the country, avoiding the tax. That's what I believe!"

Louise jumped up energetically. "Now our job is to trap Hofstatter!"

"You mean to try to find him in Plattsburg?"

"I don't believe he's there—Or any lace-makers, either. We might stop and find out—and then go on to Montreal—to the Convent—and try to catch him, or find out something about him there."

"He probably won't be back for a good while, if he has just bought out the supply," remarked Linda, gloomily.

"True," admitted Louise. "But let's fly to Plattsburg anyhow, and investigate. We've gotten along O.K. here in New York. If we can only do as well there!"

"Well, it's only December twenty-seventh. We have plenty of time before school starts again."

"Now to send Ted a night-letter!" Louise reminded her chum. "New York to Plattsburg—Plattsburg to Montreal—Montreal to the Convent, with the time figured as closely as possible, and a telegram to him each night if we are safe."

"Righto! We'll stay all night at Plattsburg tonight. And we ought to be at the Convent tomorrow—December twenty-eighth."