“Well, you remember when we went nutting?” said Libbie.  “I carried a bottle with me with—­with my name and address written on a slip of paper inside.  I read about that in a book.  And I said to leave an answer in the same bottle.  I—­I buried it just at the foot of the hill, before we began to climb.  Louise was with me, but she was hunting for specimens for her botany book.”

“So that’s why you hung back, was it?” said Betty.  “I wish to goodness Louise was more interested in what is going on around her.  She might have stopped you.  Go on—­what happened to your silly bottle?”

“I buried it,” repeated Libbie, “and two days after I went out and dug it up.  And there was an answer in it.”

“What did it say?” demanded Betty practically.

“I’ve got it here—­” Libbie reached under her pillow and pulled out a slip of paper.

“It says ’Leave ten dollars in this same place to-night, or Mrs. Eustice shall hear of this.’  And, of course,” concluded Libbie, “I put ten dollars in the bottle, because whoever found it had the slip with my name on it to show Mrs. Eustice.”

Betty studied the paper.  The handwriting was a strong backhand, not at all an illiterate hand.

“Oh, dear, what shall I do?” wailed Libbie.  “He keeps asking for more, and I won’t have any money till the first of the month.  I only meant to do like the girl in the book—­have a thrilling unknown correspondent.  I never knew he would ask for money!  Suppose he is a horrid, dirty tramp and he comes and tells Mrs. Eustice he found my note?  I should die of shame!”

“I’ll have the money ready for you in the morning,” said Betty firmly.  “I have that much.  But, of course, he’ll keep demanding more.  I do hope, Libbie, that if you ever get out of this mess, you’ll be cured of some of your crazy notions!”

“Oh, I will,” promised Libbie earnestly.  “I will be good, Betty.  Only don’t tell Bobby.”

She was manifestly relieved by her confession, and when Miss Morris came in to send Betty back to her own room, Libbie curled down contentedly for a restful night.

Not so poor Betty.  She turned and tossed, wondering how she could get more money for her chum without arousing suspicion.

“What ever made her do a thing like that!” she groaned.  “Of all the wild ideas!  The twenty will take every cent I have.  I must see Bob and borrow from him.”

Libbie was much improved in the morning—­so well, in fact, that after breakfast in bed she was permitted to dress and go to her room, though strictly forbidden to attend classes or go out of doors.  Betty brought her the twenty dollars and when school was in session, the benighted Libbie sped out to her buried bottle and put the money in it, regaining her room without detection.

Two days later there was another demand for money, and two days after that, another.  Libbie visited the bottle regularly, afraid to let a day pass lest the blackmailer expose her to the principal.  Betty had seen Bob at a football game, and had borrowed fifteen dollars from him.  She could not write her uncle, for communication with him was uncertain and her generous allowance came to her regularly through his Philadelphia lawyer.