Linda and Louise went up to their room at the hotel naturally supposing that their presence was unknown to Bess Hulbert.

It happened, however, that she was to hear about them at the desk.

When Bess left her brother in the lobby, she went straight to the clerk and asked for her key. It was a fine day, promising a fine night; she decided to leave for New York as soon as she had packed her bag. But the information caused her to change her mind.

"Do you happen to know the young lady flyers, Miss Smith?" inquired the clerk, for Bess had registered as "Anna Smith" at the hotel.

"What young ladies?" she asked, carelessly.

"Two girls who just flew in from New York. Mighty attractive ones, too!" He examined the register. "Linda Carlton and Louise Haydock."

"Hm!" mumbled Bess, wonderingly. What could have brought them up here to Plattsburg?

"I've heard of them," she replied. "How long are they staying?"

"Just over night. Going over to Montreal in the morning, I believe."

Bess was silent a moment, thinking rapidly.

"I guess I'll stay here over night, after all," she concluded. "Night flying isn't so good, if you don't have to do it."

"Wise young lady!" observed the clerk. "If you want to meet these girls, they're still out there in the dining-room, eating. I know flyers always like to get together—for 'ground flying,' as Lindbergh calls it."

"I don't care much about meeting those particular girls," replied Bess, scornfully. "They're only beginners—I dare say this is their first real flight. Yet the way they talk you'd think they had been pilots for years.... No, thank you. I guess I'll go up now, and take a rest. Will you have my dinner sent up to my room?"

She disappeared into the elevator, and when Linda and Louise came out of the alcove, they thought she had gone back to New York. When they stopped at the desk the clerk made no mention of "Miss Smith" because she had spoken so contemptuously of these young girls.

"What's your idea of a way to spend our time here?" asked Louise, as they unpacked their bags. "It's only five o'clock; we can't go to bed yet."

"Let's look for 'Hofstatters' in the phone book," suggested Linda. "Just for fun, because we probably shan't learn anything, but it wouldn't do any harm."

"O.K. with me. I'm glad his name isn't Smith or Jones, then it wouldn't be so easy."

Louise opened the telephone book on the small table beside the bed, and searched diligently.

"I've found three," she announced a minute later. "Amos, Charles, and Mary. But what shall we say when we call?"

"Say we come from the firm of J. W. Carwein, New York City—it'll be the truth, because we have just come from there—and we want to know when he will have another box of lace-work to sell."

"Great!" approved Louise, smiling at the joke. "And if we should happen to locate the man, what shall we do? Make an appointment?"

"Of course! He would have to tell us exactly where he got the goods, and if he isn't telling the truth and is smuggling them in from Canada, we can have him arrested.... But we'll never meet luck like that!"

"I speak for Amos," said Louise. "I like the name. Besides, nobody with a name like that from the Bible could be crooked."

"And Mary ought to be out of it," remarked Linda. "Though of course she might have a son or a brother."

They took a few minutes to write down exactly what they would say, and began calling the numbers. But without success—that is, until they came to Mary. Amos Hofstatter grew angry, believing it was another wrong number, and shrieked that he had never heard of anybody named Carwein. Charles Hofstatter, identifying Louise's voice as that of a young girl, tried to make a date with her, but she scornfully replied, "Act your age!" and hung up with a bang.

Linda took the telephone to give the last call, the number listed for Mary Hofstatter.

A rather feeble voice answered.

"Who? What did you say?" the woman, evidently elderly, asked.

Linda repeated her message.

"You want my son?" she guessed. "You are Miss Smith?"

"No," replied Linda, firmly. "But we are from Carwein and Co., linen importers, and we want to see him."

"Oh—I—don't know where he is," stammered the other, nervously. "Miss Smith knows. Anna Smith. Ask her."

"But where is Anna Smith?" persisted Linda.

"I don't know anything about it at all!" protested the woman. "Good-by!"

Linda turned excitedly to Louise. "We're on the right track," she said. "But imagine locating an Anna Smith, North America!" She shook her head hopelessly.

"It wouldn't do much good anyway," remarked her chum. "This Hofstatter is probably some weak fellow, who will do anything for money. Our best plan is to strike out for the Convent."

"What do you say if we cut out the stop at Montreal altogether?" asked Linda, studying her map. "This Convent is between Montreal and Quebec, and I don't see why we shouldn't fly straight to it. We'll save a lot of time."

"Time is precious," agreed Louise. "But remember what Ted said, about inquiring at the Montreal airport for a landing place."

"I know, but we can't always do what Ted says. We're not beginners now, Lou. And I'm sure there will be a good place—the country is so open."

"O.K. with me. If tomorrow is a clear day, as it looks as if it is going to be, we can fly low enough to watch the ground pretty closely."

"Then it's settled," concluded Linda. "Give me ten minutes with this map, and I'll be finished. Then we can go to the movies, and buy a paper so that we'll have the weather prediction for tomorrow."

The next four hours passed pleasantly for the girls, and they stopped at a drug-store on their return from the early show at the theater, to buy a sandwich and some hot chocolate, which was all the supper they wanted. By ten o'clock their lights were out and they were fast asleep.

Soon after breakfast the following day, which was bright and sunshiny, Linda and Louise returned to the airport and took off into the bright blue sky. Everything seemed favorable; they had no idea that only a few hundred yards behind them a plane was following them, a plane whose pilot had no love for Linda Carlton or Louise Haydock.

"You didn't bring any coffee, did you?" asked Louise, as they sped on over the frozen country, glimpsing the St. Lawrence as they passed.

"No," returned her companion. "Only some sweet chocolate, matches and about three cans of baked beans, which I always carry. I've read a lot about making fire without matches, but if we ever have another experience like that one last summer, and come down in a lonely spot, I want matches. And something to keep us from starving."

Even in the companion cockpit, which was one of the nicest features of the Arrow Pursuit, conversation was rather difficult, and the girls only talked occasionally. Sometimes they would press each other's fingers just as a joyous signal of their pleasure in flying together.

It was Linda who first noticed the plane behind her.

"See what kind it is, Lou—if you can," she advised.

"Can't very well," replied the other, attempting to lean out and peer through her glasses. But it was too far away to identify.

"Hope it's not a thief or anybody like that," remarked Linda, recalling the other time a plane had followed them, in order that the pilot might steal Kitty Clavering's necklace.

"Don't worry!" returned Louise. "We haven't anything like pearls with us today!"

"You have your earrings! And besides, we must have a couple of hundred dollars between us."

But the plane had disappeared again, and the girls gave their attention to the country beneath them, flying low enough to watch the children on their sleds, and the skaters on the frozen lakes. The winter sports looked so inviting that both Linda and Louise wished they could stop and join in.

"Maybe we can do that tonight," exclaimed Louise. "If we get back to Montreal safely."

"Aunt Emily wouldn't approve," Linda reminded her.

"Your Aunt Emily doesn't approve of any of this! But anyway, it's all in a good cause."

"And we've gotten along fine so far...."

For some miles farther they watched the ice-covered lakes and the snow-covered ground, and the thick trees that dotted the landscape. The vastness of the woods was a little terrifying; Linda shivered when she thought what it would be like to be lost in them, at this time of the year. Their supplies might last them a day—after that they would certainly perish.... She pulled herself sharply from such gruesome thoughts; a pilot was always in a certain amount of danger, and had no right to brood upon it. Prepare for the unexpected, yes—and then forget it!

It was still early in the afternoon when they sighted the Convent. Large and picturesque, like those of the old world, as typical of French Canada as most of Quebec. Linda gave a cry of Joy.

"I'll have to circle awhile," she shouted to Louise, "till I can find a spot without trees for a landing. But I am sure there must be one—away from these hills."

Soon she was rewarded, for there proved to be a very good place—flat, even ground, covered with only a coating of snow.

Both girls were a little timid about the reception they might get. Were these nuns, living their quiet lives, used to airplanes, or would they resent the noise, breaking in upon their meditations and work? Trembling a little, but remembering their fondness for her Aunt Emily, Linda brought out her handkerchief which they had made, in readiness to show it to them as proof of her identity. Then she and Louise started towards the Convent, which was the distance of perhaps two city blocks away.

Before they had gone a half of the distance, they saw children running towards them from over the hill, children probably from the village beyond. The girl stopped, smiling.

"Candy! Candy!" cried the youngsters, and Linda went back to the plane and dug out their supply of chocolate and handed it over to them.

"It was sort of nice to see those kids," remarked Louise, as they again started towards the Convent. "Somehow they make it seem more alive. Oh, Linda, I do hope we don't interrupt the nuns at a service!"

But she need not have worried, for as soon as the girls entered the building they saw a group in a big room, engaged with their needles. What an opportune time to come!

"You do the talking, Lou!" urged Linda. "You always know what to say better than I do."

One of the sisters came forward and smiled.

"Welcome!" she said in French. "Come over to the fire and warm yourselves."

Fortunately, both girls had studied this language, and understood what she said. Gratefully they walked over to the old-fashioned stone fireplace, where a frugal fire of fagots was burning, and a kettle, hanging on a crane, was singing and bubbling.

"Merci, beaucoup!" replied Louise, to let the good woman know that she understood her, and appreciated her offer.

"Has anything happened?" asked the sister, still in French.

"Happened? Why?" returned Louise.

"You were here yesterday, and bought everything that we had made. The Mother Superior told us."

"But we weren't here yesterday!" protested Louise.

"Yes. In an airplane."

Linda and Louise looked at each other knowingly. It must have been Bess Hulbert—in the Moth! That would explain her presence in Plattsburg. They were sure of it now.

"That was somebody else," explained Linda. "Did you see her?"

"No, we did not see her. The Mother Superior saw her. Instead of sending a man, she said Mr. Carlton thought we would prefer a lady. And she paid more—and gave the little village children candy. Oh, she is good! We are starting a little school for the village children."

What Louise wanted to say was "She is an impostor!" but she could not think of the French word for "impostor," and besides, what was the use of telling all this to these simple-hearted sisters? Instead, she asked for the Mother Superior.

"She is away, visiting a sick friend, in Quebec. She will not be back until tomorrow."

Louise sighed; there was nothing they could do now. But they had found out what they wanted; it was Bess Hulbert who was smuggling the goods into the country, and stealing Mr. Carlton's business. It would be an easy thing now to catch her and have her arrested.

"We must go now," said Louise. "Before it gets dark."

"Oh, but have something to eat!" urged the sister. "Some tea and biscuits."

Seeing that these good women might be hurt if they refused, the girls accepted the invitation and sat down to the simple meal. It was plain, but good, and they discovered that they were very hungry, for they had not eaten since breakfast.

"Now let us show you over the Convent," offered another, and while they accompanied several of the nuns about the old, meticulously neat rooms, they heard the roar of a plane, making a landing not far away. Immediately Linda glanced out of the window, to see whether her Arrow was safe, and she saw another plane landing quite near. But before the girls left the Convent, the latter had disappeared.

"Now back to Montreal for the night—and then hot foot after Bess Hulbert!" cried Linda, as she started the motor. "If we accuse her of being a smuggler, and she promises to stop, and leave Daddy alone, we won't have to have her arrested."

"But first," qualified Louise, "we must _catch_ Bess Hulbert!"