The dinner party was delightful. The “Automobile Girls” had not had such a good time since their arrival in Washington. Mrs. Wilson was a charming hostess. She was particularly gracious to Bab, and the young girl decided to forget the disquieting suspicions she had harbored against this fascinating woman and enjoy herself.

It was almost ten o’clock. Mr. Hamlin had not yet arrived at Mrs. Wilson’s. Bab was sitting in one corner of the drawing-room talking gayly with a young Annapolis graduate, who was telling her all about his first cruise, when Elmer Wilson interrupted them.

“I am terribly sorry to break into your conversation like this, Miss Thurston,” he apologized. “But Mother wishes to have a little talk with you in the library before you leave here. I am sure I don’t know what she wishes to see you about; she told me to give you her message and ask no questions. May I show you the way to her!”

Bab’s gay laughter died on her lips. She rose at once and signified her willingness to accompany Elmer to the library, but both young men noticed that her face had grown grave and she seemed almost embarrassed.

Elmer Wilson wondered why Miss Thurston had taken his mother’s simple message so seriously. He was almost as embarrassed as Bab appeared to be.

When Barbara entered the room where she had received the envelope from Peter Dillon the room was but dimly lighted. Two rose-colored shades covered the low lamps, and great bunches of pink roses ornamented the mantel.

Mrs. Wilson wore a black and white chiffon gown over white silk and had a little band of black velvet about her throat from which hung a small diamond star. Her beautiful white hair looked like a silver crown on her head. She was leaning back in her chair with closed eyes when Bab entered the room, and she did not open them at once. She let the young girl stand and look at her, expecting her unusual beauty to influence Bab, as it had many other older people. Mrs. Wilson looked tired and in a softened mood. Her head rested against a pile of dark silken cushions. Her hands were folded, in her lap.

She opened her dark eyes finally and smiled at Barbara. “Come here, Barbara,” she commanded, pointing to a chair opposite her.

Bab looked at her beautiful hostess timidly, but her brown eyes were honest and clear. “You sent for me?” Bab queried, sitting down very stiff and straight among the soft cushions.

“Of course I did,” Mrs. Wilson smiled. “And I should have done so before, only you and I have both been too busy. I am so glad you came to my tea to-day.” Mrs. Wilson reached out her slender white hand and took hold of Barbara’s firm brown one. “I want to make you a very humble apology,” she continued. “I am very sorry that I was obliged to be away the other day when you called. I left the envelope with Mr. Dillon. I received your note yesterday, so I know that it was delivered into your hands. I did not return until after seven o’clock the other night, so it was just as well you didn’t wait for me. I knew I could trust Mr. Dillon to give it to you.”

The girl made no reply. She did not dare raise her eyes to the other woman’s face for fear Mrs. Wilson would divine from their expression that Bab knew she had lied. At the same time a thrill of consternation swept over her. What had been Mrs. Wilson’s object in lending her the money? Bab was now sure that the loan had not been made disinterestedly. But what had Peter Dillon to do with it? It looked very much as though Mrs. Wilson and the attache were playing a game, and were seeking to draw her into it. She resolved at that moment that she would write to her mother for the money, or ask Ruth for it. She would do anything rather than remain in Mrs. Wilson’s debt. There was something about the intent way in which her hostess looked at her that aroused fresh suspicion in her mind. Bab braced herself to hear what she knew instinctively was to follow.

“I am so glad I was able to help you,” Mrs. Wilson purred, continuing to watch the young girl intently. “I know that you meant what you said when you declared that you hoped to some day be able to do some favor for me. I did not think then that I should ever wish to take you at your word, but strange as it may seem, you are the very person I have been looking for to help me with a joke that I wish to play upon Mr. Hamlin. You know, Mr. Hamlin is a very methodical man. Well, I wagered him a dozen pairs of gloves, the other day, that he would misplace one of his beloved papers. And I hope to win the wager. What I wish you to do is to secure a certain paper from his desk and give it to me. He will never know how I obtained it. Of course I shall return it to him in a day or so, after he acknowledges his defeat and pays his wager.”

Barbara shook her head. “I don’t think I can take any part in any such joke, Mrs. Wilson,” she said, looking appealingly at her hostess. “You don’t really mean that you wish me to take one of Mr. Hamlin’s papers without his knowledge, and then give the paper to you?”

“Certainly, child, I do mean just that thing,” Mrs. Wilson said, laughing lightly. “You need not take my request so seriously. Mr. Hamlin will appreciate the joke more than any one else when I have explained it to him. Won’t you keep your word and grant me this favor?”

“I can’t do what you ask, Mrs. Wilson,” Bab said slowly. “I’m awfully sorry, but it wouldn’t be honorable.”

Mrs. Wilson turned away her head, so that Barbara could not see the expression of her face. “Very well, Miss Thurston,” she said sharply. “Don’t trouble about it, if you think you will be committing one of the cardinal sins in doing me this favor. But don’t you think you are rather ungrateful? You were perfectly willing to accept my offer the other day when you were in need of money to pay your sister’s debt, but now you are in no hurry to cancel your obligation. I consider you an extremely disobliging young woman.”

Barbara sat silent and ashamed. Yet she made no effort to propitiate her angry hostess.

The butler came to the library door to announce the arrival of Mr. Hamlin.

Barbara rose quickly. “I am so sorry not to be able to do you the favor you asked of me, Mrs. Wilson,” she said in a low tone.

Mrs. Wilson did not reply. Then in a flash Barbara Thurston remembered something! It was the promise Marjorie Moore had asked of her, and which Ruth Stuart had insisted upon her making. Without recalling that promise at the time, Bab had still kept her word. She had been asked to do some one a favor ­and she had refused. But of course Marjorie Moore must have had some other thing in mind when she made her curious demand. Now that Barbara thought again of her vow, she determined to be wary for the rest of the evening and to keep as far away from Peter Dillon as possible.

“I am going to play chaperon at your house in the near future, Harriet,” Mrs. Wilson announced, as her guests were saying good night. “Your father says he is to be out of town on business and that I may look after you.”

“We shall be delighted to have you, Mrs. Wilson,” Harriet returned politely, though she wondered why her father had suddenly requested Mrs. Wilson to act as chaperon. Harriet had often stayed at home alone with only their faithful old servants to look after her, when her father went away for a short time. And now that she had the four “Automobile Girls” as her guests, she did not feel in need of a chaperon.

Peter Dillon had not spoken to Bab again during the evening, but had studiously avoided her, and Bab was exceedingly glad that he had kept his distance. But as she put on her coat to go home, she heard the rustle of a small piece of paper.

Barbara glanced down at it, of course, and found that some one had pinned a folded square of paper to the inner lining of her coat.

She blushed furiously, for fear one of the other guests would discover what had happened. Bab hated sentimentality and secrecy more than anything in the world. Inside the folded square of paper she found the tiny faded rose-bud, Peter Dillon had placed in his pocket that day when he had picked the two buds in the old Washington garden at Mt. Vernon.

On the way downstairs, Barbara still kept the flower in her hand. But when she found Peter’s eyes were upon her she deliberately crushed the little rose-bud, then defiantly tossed it away.