The next morning, Peter Dillon was lounging in Mrs. Wilson’s library, chatting with her on apparently easy terms.

“I think it is a special dispensation of Providence that sent the ‘Automobile Girls’ to Washington to visit Harriet Hamlin just at this particular time, Mrs. Wilson,” declared Peter Dillon.

Mrs. Wilson walked back and forth across her drawing room floor several times before she answered. She looked older in the early morning light. But her restlessness did not disturb Peter, who was reclining gracefully in a chair, smoking a cigarette.

“I am not sure you have reason to bless Providence, Peter Dillon,” Mrs. Wilson protested. “What a man you are! You simply cannot judge all girls by the same standard. Some day you are going to meet a girl who is cleverer than you are. And then, where will you be?”

“Oh, I’ll go slowly,” Peter argued. “I know I am taking chances in making friends with the clever one. But she has more nerve and courage than the others. I am sure it will be much better to leave Harriet out of the whole business, if possible.”

“All right, Peter,” Mrs. Wilson agreed. “Manage your own affairs, since this happens to be your own special joke. But you had much better have left the whole matter to me.”

“And spoil my good time with five charming girls?” Peter protested, smiling. “No, Mrs. Wilson; that is too much to ask of me. If I can’t carry the thing off successfully, you will come to the rescue and help me. You’ve promised that. We have had our little jokes together before. But this strikes me as being about the best of the whole lot. We will have everybody in Washington laughing up his sleeve pretty soon. There will be a few people who won’t laugh, but so long as we keep quiet we need not worry about them. Has Elmer gone to work? I know I have made you a dreadfully early visit. It is very charming of you to be up in time to see me.”

“Don’t flatter me, Peter; it is not worth while,” Mrs. Wilson said angrily. Then she smiled. “Never mind, Peter; you can no more help flattering than you can help breathing, whether your reason is a good or a bad one. I suppose it is because you are an Irishman. By the way, Elmer admires one of these charming ‘Automobile Girls.’ He has talked of no one else except Mollie Thurston since Harriet’s tea. Be careful what you say or do before him.”

“I shall be careful,” Peter returned easily. “My attentions are directed toward the other sister. How have you managed to keep that big boy of yours so much in the dark about ­oh, a number of things?” finished Peter.

“It is because Elmer has perfect faith in me, Peter,” Mrs. Wilson answered, passing her hand over her eyes to hide their expression.

“As all other men have had before him, my lady,” Peter avowed. “Is it true that Mr. William Hamlin is now a worshiper at your shrine?”

“Absurd!” protested Mrs. Wilson. “Here comes Elmer.”

“Why, Peter Dillon, this is a surprise!” exclaimed the young lieutenant, walking into the room in search of his mother. “I never knew Mother to get up so early before. I have just been inquiring of your maid, Mother, to know what had become of you. Harriet Hamlin wants you to chaperon us on an automobile ride out to Mt. Vernon and along the Potomac River. Charlie Meyers is giving the party, and Harriet thinks her father won’t object if you will go along to look after us. That Charlie Meyers is an awful bounder! But Harriet wants to show her little Yankee visitors the sights. Do come along with us, Mother. For I have a fancy I should like to stroll through the old Washington garden with ‘sweet sixteen.’”

“I will chaperon you with pleasure, Elmer,” Mrs. Wilson agreed. “But what about you, Peter? Are you not invited?”

Peter looked chagrined.

“No; I am not invited, and I call it unkind of Harriet. She knows I am dreadfully impressed with the ‘Automobile Girls.’”

Mrs. Wilson and Elmer both laughed provokingly. “That is just what’s the trouble with you, Peter. Harriet is accustomed to your devotion to her. Now that you have turned your thoughts in another direction, she may look upon you as a faithless swain,” Mrs. Wilson teased.

“Don’t undertake more than you can manage, Peter,” teased Elmer Wilson.

“That is good advice for Peter. Remember, Peter, I have warned you. Some day you will run across a girl who is cleverer than you are. Then look out, young man,” Mrs. Wilson repeated.

But Peter only laughed cheerfully. “What girl isn’t cleverer than a man?” he protested. “Au revoir. I shall do my best to persuade Harriet to let me go along with her party this afternoon. I suppose we shall be starting soon after luncheon, as it is Saturday.”

“Mother, can you let me have some money?” Elmer asked, as soon as Peter was out of hearing. “I am ashamed to ask you for it. But going out in society does cost a fellow an awful lot.”

Mrs. Wilson shook her head. “I am sorry, Boy; I can’t let you have anything just now. I am short of money myself at present. But I expect to have some money coming in, say in about two weeks, or even ten days. Then I can let you have what you like.”

“How shall we divide our party for the motor ride, Ruth?” asked Harriet Hamlin about two o’clock on the afternoon of the same day.

Ruth’s red car was standing in front of Mr. Hamlin’s door with another larger one belonging to Harriet’s friend, Charlie Meyers, waiting behind it.

The automobile party stood out on the side walk and Peter Dillon had somehow managed to be one of them.

“Suppose, Barbara, Grace and Hugh Post go along with me, Harriet?” Ruth proposed. “Mr. Meyers’ car is larger than mine. He can take the rest of the party.”

“What a division!” protested Peter Dillon, as he climbed into Ruth’s automobile and took his seat next Bab. “Do you suppose, for one instant, that we are going to see Hugh Post drive off, the only man among three girls? Not if I can help it!”

The two automobiles traveled swiftly through Washington allowing the four “Automobile Girls” only tantalizing glimpses of the executive buildings which they passed on the way.

In about an hour the cars covered the sixteen miles that lay between the Capital City and the home of its first President.

Such a deep and abiding tranquillity pervaded the atmosphere of Mt. Vernon that the noisy chatter of the young people was, for an instant, hushed into silence, as they drove through the great iron gates at the entrance to Mt. Vernon, and on up the elm-shaded lawn to the house.

Although it was December, the fall had been unusually warm and the trees were not yet bare of their autumn foliage; the grass still looked smooth and green under foot.

The “Automobile Girls” held their breath as their eyes rested on the most famous historic home in America.

“Oh, Ruth!” exclaimed Bab. But when she saw Peter’s eyes smiling at her enthusiasm she stopped and would not say another word.

Of course, Mt. Vernon was an old story to Mrs. Wilson, to Harriet, and indeed to the entire party, except the four girls. But they wished to see every detail of the Washington house. They went into the wide hall and there beheld the key to the Bastile presented by Lafayette to General Washington. They examined the music room, with its queer, old-fashioned musical instruments; went up to Martha Washington’s bedroom and even looked upon the white-canopied bed where George Washington died. Indeed, they wandered from garret to cellar in the old house. But it was a beautiful afternoon and the outdoors called them at last.

And, after all, it is the outdoors at Mt. Vernon that is most beautiful. The house is a simple country home with a wide, old-fashioned portico and gallery built of frame and painted to look like stone.

But there is no palace on the Rhine, no castle in Spain, that has a more beautiful natural situation than Mt. Vernon. It stands on a piece of gently swelling land that slopes gradually down to the Potomac, and commands a view of many miles of the broad and noble river.

Bab and Ruth managed to get away from the rest of their party and to slip out on the wide colonnaded veranda.

“How peaceful and beautiful it is out here,” Ruth exclaimed, with her arm around her friend’s waist. “It seems to me that, if I lived in Washington, I would just run out here whenever anything uncomfortable happened to me. I am sure, if I spent the day at Mt. Vernon, I should not feel trouble any more.”

Barbara stood silent. A vague premonition of some possible trouble overtook her.

“Ruth,” Bab asked suddenly, “do you like Harriet’s friend, Peter Dillon? Every now and then he talks to me in the most mysterious fashion. I don’t understand what he means.”

Ruth looked unusually grave. Then she answered Bab in a very curious tone. “I know you have lots of common sense, Bab, dear,” Ruth began. “But promise me you won’t put any special faith in Peter Dillon. He is not one bit like Hugh, or Ralph Ewing, or the boys we met at the Major’s house party. When I meet any one who is such a favorite with everyone I always wonder whether he has any real feelings or whether he is trying to accomplish some end. I suppose Peter Dillon can’t help striving to be agreeable to everyone.”

Bab laughed a little. “Why, Ruth,” she protested, “that idea does not sound a bit like you. You are sweet to everyone yourself, dear, and everyone loves you. But I do know what you mean about Peter Dillon. I ­”

“Hello,” cried Mollie’s sweet voice. She waved a long blue scarf toward Ruth and Bab. Mollie and Elmer Wilson were standing on the lawn, examining the motto on the sun dial. It read, “I record none but sunny hours.”

“Let me write down that motto for you, Miss Thurston,” Elmer Wilson suggested. “I hope you may follow the old sun dial’s example and record none but sunny hours yourself.”

“Ruth!” called Hugh, coming around from the other side of the porch with Peter Dillon. “Well, here you are, at last! It is not fair for you two girls to run off together like this. Harriet has disappeared, and Mrs. Wilson is hiding somewhere. Do you remember, Ruth, you promised to go with me to see the old Washington deer park. It has just been restocked with deer. Won’t you come, too, Bab?”

Barbara shook her head as Hugh and Ruth walked off together. Bab felt sure that Hugh would like to have a chance to talk with Ruth alone, for they had never ceased to be intimate friends since the early days at Newport.

Peter Dillon stood looking out at the river, whistling softly, “Kathleen Mavourneen.” It was the song Barbara had first heard him whistle in the drawing-room of Mr. Hamlin’s house. The young man said nothing, for a few moments, even when he and Bab were alone. But when Bab came over toward him, Peter smiled. He had his hat off and he had run his hands through his dark auburn hair.

“I say, Miss Thurston, why can’t you make up your mind to like me?” he questioned. “Surely you don’t suspect me of dark designs, do you? You American people are so strange. Just because I am half a Russian you think I have some sinister purpose in my mind. I am not an anarchist, and I don’t want to go about trampling on the poor. I wish you could meet the Russian ambassador. He is about the most splendid-looking man you ever saw. I know him, well, you see, because my mother was a distant cousin of his.”

Barbara laughed good-humoredly. “You seem to be a kind of connecting link between three or four nations ­Russia, America, China. What are your real duties at your legation?”

Barbara looked at her companion with a real question in her brown eyes ­a question she truly desired to have answered. She was interested to know what duties an attache performed for his embassy. Peter, in spite of his frivolities, claimed to be a hard worker.

“You have not seen the loveliest part of Mt. Vernon yet, Miss Thurston,” Peter Dillon interposed just at this instant. “I want to show you the old garden, and we must hurry before the gates are closed. Yes; I know I did not answer your question. An attache just makes himself generally useful to his chief. But if you really want to know what my ambition is, and how I work to achieve it, why some day I will tell you.” Peter looked at Bab so seriously that she answered quickly:

“Yes, I should dearly love to see the garden.”

Bab and Peter Dillon wandered together through the paths formed by the box hedges planted in Martha Washington’s garden more than a century ago.

Neither seemed to feel like talking. The young man had seen the gardener as they entered the enclosure, and had persuaded him to allow them to go through the lovely spot alone.

Bab’s vivid imagination brought to life the old colonial ladies who had once wandered in this famous garden. She saw their white wigs, their powder and patches and full skirts. So Bab forgot all about her companion.

Suddenly she heard Peter give a slight exclamation. They had both come to the end of the garden walk. There before them stood a great rose tree. Blooming in the unusually warm sunshine were two rose-buds, gently tipped with frost.

“Ah, Miss Thurston, how glad I am we found the garden first!” Peter cried. “This is the famous Mary Washington rose, which Washington planted here in his garden, and named in honor of his mother. Wait here until I find the gardener. I am going to make him let us have these two tiny rose-buds.”

“How nice Peter Dillon really is,” Bab thought. “Ruth was mistaken in warning me against him. Of course, he does not show on the surface what he actually feels. But perhaps I shall find out he is a finer fellow than we think he is. Mr. Hamlin says Harriet is wrong in believing Peter is never in earnest about anything.”

“It’s all right, Miss Thurston,” called Peter, returning in a few minutes with his eyes shining. “The gardener says we may have the roses.” The young fellow dropped down on his knees before the rose bush without a bit of affectation or self-consciousness. He skilfully cut the two half faded rose-buds from the stalk and handed one to Barbara.

“Keep this, Miss Thurston,” he said earnestly. “And if ever you should wish me to do you a favor, just send the flower to me and I shall perform whatever task you set me to do to the best of my skill.” Peter looked at his own rose. “May I keep my rose-bud for the same purpose?” he begged quietly. “Perhaps I shall send my flower to you some day and ask you to do me a service. Will you do it for me?”

“Yes, Mr. Dillon, I will do you any favor that I can,” Bab returned steadily. “But I don’t make rash promises in the dark. And I have very little opportunity to do people favors. You make me think of the newspaper girl, Marjorie Moore. She tried to force me into a promise without letting me know what she wanted, the first day I saw her. Does everyone try to get some one to do something for him in Washington?”

At the mention of Marjorie Moore’s name the change in Peter Dillon’s face was so startling that Barbara was startled. Just now he did not look in the least like an Irishman. His lips tightened into a fine, cruel line, his eyes grew almost black and had a queer, Chinese slant to them. It suddenly dawned on Barbara, that Russians have Asiatic blood in their veins and are often more like Oriental people than they are like those of the western world.

But Peter only said carelessly, after he had regained control of his face: “Miss Moore doesn’t like me; and frankly, I don’t like her. She told you she did society work for her newspaper. She does a great deal more. She is constantly watching at the legations to see if she can spy on any of their secret information. It is not good form to warn one girl against another. But if I were you, Miss Thurston, I would take with a grain of salt any information that Miss Moore might give you.”

Barbara answered quietly: “Oh, I don’t suppose Miss Moore will tell me any of her secrets. She does not come to Mr. Hamlin’s except on business. Harriet does not like her.”

“Good for Harriet!” Peter muttered to himself. “It may be Harriet, after all!”

“Barbara Thurston, you and Peter come along this minute,” Harriet ordered unexpectedly. “Don’t you know we shall be locked up in Mt. Vernon if we stay here much longer. Ruth’s automobile is already filled and she is waiting to start. You and Peter are to get into Mr. Meyers’ car with me. We have another hour before sunset. We are going to motor along the river and have our supper at an inn a few miles from here.”

As Peter Dillon ran ahead to join Harriet Hamlin, a small piece of paper fell out of his pocket. Barbara picked it up and slipped it inside her coat, intending to hand it back to Mr. Dillon as soon as she had an opportunity. But there were other things that seemed of more importance to absorb her attention for the rest of the evening. And Barbara was not to remember the paper until some time later.