Miss Helen Campbell was laid low with a sick headache the day after the orange grove party.

“A little too much juice of the fruit, my dear,” she explained to Billie, who had tiptoed into her room to see if there was anything she could do. “But you mustn’t stay with me. I shall be all right as soon as my head stops throbbing. Only never show me another orange as long as I live. Get Edward to look after you and go for a ride in the Comet. You mustn’t miss a moment of this beautiful visit on my account.”

“Do you think there would be anything out of the way in our going over to see Virginia, Cousin Helen? She is not working here any longer the housekeeper says, and I suppose we shall find her at home. We could take her for a motor ride and bring her back to luncheon.”

“Certainly, child, if she will come. Ask her brother’s opinion. He ought to know better than any one else. But whatever you do, be sure and be back to lunch or I shall be very uneasy.”

Billie wished to see Virginia very much. She also wished to find Edward, and the plan of the morning she hoped would bring both of these things about. She felt worried, and anxious to disburden her soul of its secret.

Her three friends had noticed at breakfast how quiet Billie was, for her frank and honest face had never been able to conceal any emotion which saddened or brightened it.

“Aren’t you feeling well to-day, dear?” Mary asked, as they hurried down the hotel walk to look for Edward, who they had been told was probably at the boat landing.

“Quite well,” replied Billie.

“Wilhelmina,” said Nancy sternly, “you know something and you won’t tell. Now, get it out of your system right off, or it will be making you ill.”

Elinor said nothing at all. It was impossible for her to explain her feelings just then even to herself. She was hurt with Billie for no good reason, and she was angry and ashamed of herself for permitting this ugly little bitterness to enter her mind.

“Do tell us, Billie,” pleaded Nancy, whose curiosity when with her three intimate friends was insatiable.

“But it isn’t mine to tell,” answered Billie desperately.

“Ha! She admits she has a secret,” cried Nancy dramatically.

“The only way for you to learn this secret,” said Billie, cornered at last by her own confession, “is to find it out for yourselves. I can’t tell because I promised not to. For some reason, which I don’t know any more than you do, it’s very important for the secret to remain a secret, and everything depends on its being kept a secret. That’s all I can tell you, because, except for the actual thing itself, that’s all I know.”

“Heavens, how mysterious!” cried Nancy. “I feel I shall burst in a minute if I don’t find out.”

“I’m afraid you’ll have to burst then, you inquisitive child,” laughed Billie, giving her a friendly shake.

It was really something of a relief to talk about it, even in this vague and unsatisfactory manner.

Edward was nowhere to be seen at the boat landing.

“Perhaps he’s in the Firefly,” suggested Mary.

The motor-boat was the last of a row of launches moored to the landing, and as they approached they heard a clear, boyish voice, singing:

“Onthyfairbosom,silverlake,
Thewildswanspreadshissnowysail,
Androundhisbreasttheripplesbreak,
Asdownhebearsbeforethegale.”

Nancy and Mary, who were already half down the flight of steps leading to the boats, paused to listen. Billie also lingered on the platform, when suddenly Elinor, who had lagged behind, busy with her own thoughts, ran up to her friend and seized her by the shoulders with a little low cry that was half a laugh and half a sob.

“Billie Campbell,” she whispered, “I know the secret. They’ve changed places. But why did they do it?”

“For fun, at first,” replied Billie. “And now I don’t understand. Something has happened because Edward l’Estrange is not coming back.”

The two girls looked at each other a moment in silence.

“You mean he’s left the other Edward to take his place here?” Elinor whispered.

Billie nodded.

“But that isn’t fair.”

“I’m sure it is,” said Billie stoutly. “Because—because——,” she went on lamely, “he couldn’t do anything that wasn’t fair.”

“But think what it will mean to him,” Elinor persisted. “He will have plenty of money and he can go to school and travel——”

“I know,” said Billie, “but he told me he was coming back and I believe him.”

“And Edward Paxton, what will he be doing? He will have to work for a living.”

“It will do him good.”

“You are not fussing, I trust,” called Mary, who had run back up the steps to look for them.

“No, no, only arguing,” replied Elinor.

Edward Paxton now appeared, his hands in his pockets, whistling the same air he had been singing only a moment before. His eyes met Elinor’s and he stopped in the middle of a bar. This double identity was awfully mixing. He was always forgetting that as engineer of the boat, Firefly, he was not supposed to know about music.

“What are your orders this morning, Miss Campbell?” he asked, with just a suspicion of mockery in his voice.

“Get the Comet, please, Edward,” she said, flushing. “We are going to motor out to see Virginia. Can you go with us?”

“At your service,” replied the boy, smiling broadly.

He really seemed so happy that Billie thought, after all, the news she had to tell him would not be so unwelcome.

“How do you like the life?” she asked him presently, following him to the garage, while the other three girls returned to the hotel for mail, motor veils and a last word to Miss Campbell.

“Wonderful,” he replied with enthusiasm. “If I only had a piano it would be perfect. I have just finished composing a song and I want to try it.”

“You don’t mind the work, then?”

“Not specially. You see I don’t do very much. I’ve got it down to the Firefly and the Comet, and let everything else slide.”

“But——” began Billie with a tone of protest in her voice. “After all,” she thought, “it isn’t any of my business.”

“But what?” he asked.

“I have something to tell you, Edward. What would you say if you really had to work for a living for awhile?”

“Is that what you had to tell me?” he asked smiling. “I should say I would rather study music.”

“But you aren’t studying music,” said Billie. “You’re just lying around making up pretty tunes and neglecting the work you promised to do. I’m afraid you can’t neglect it any longer, Edward. You’ve got to look alive and earn some money.”

Then Billie gave him the message she had received over the long distance telephone.

Edward was too amazed to answer at first. His lips formed the word “scoundrel,” but he seemed to have no voice. At last he burst out indignantly:

“And I thought I could trust him, Billie, when I let him have that money in advance.”

“But you can. He will be back, of course.”

“What earthly reason could he have for staying away, except to take my place? Don’t you think it’s a good deal easier life to live with a rich old grandmother, even if she is a scold, than to slave down here as an engineer and a porter and anything else that happens to come along and take insults from people?”

“But I thought you liked it?”

“I did, but not forever. Of course, I shall telegraph Grandmamma or Clarence at once and let them know he is an impostor.”

“No, you won’t,” cried Billie so suddenly that she surprised herself. “No, no, Edward, you couldn’t do that. That wouldn’t be honest. You gave him your promise, didn’t you, to look after his work until he came back. I am sure you would regret it very, very much if you didn’t. If he had not meant to come back, he would never have called me up on the telephone. You see, it wasn’t necessary. They expected to stay several days, didn’t they? But he knew I was going to be at Mr. Duffy’s lodge that afternoon, and although he seemed in a tremendous hurry, he called me up to ask me to give you that message. You are to represent him,” she repeated, “as you promised. I am sure he meant every word he said. Please, Edward, do wait until you get word from him. How can you distrust any one who looks so exactly like you? It would be like disbelieving in one’s self.”

Edward did not reply. With an angry, impatient gesture he left her, to bring the car out of the garage. Presently she climbed in beside him.

“It won’t hurt you to do something for some one else,” she went on. “I don’t want to preach, of course, but I’d just like to ask you if you ever have, that you can remember, really made a sacrifice for any one?”

“I can’t say I have,” said Edward. “Perhaps I’ve never had the opportunity.”

“Do you remember that night when we didn’t find the dead man, you told me you had been afraid all your life of daylight and dark and draughts and people and poverty? This is such a splendid chance to show you are not afraid of anything in the world, even of keeping your promise, Edward.”

“But,” he exclaimed, “I have no money, Billie.”

“Take out sailing parties and launch parties and carry baggage and do the things Edward did. Papa always said the proudest moment of his life was the first time he earned five dollars.”

“By Jove, it would be rather nice,” he said after a pause. “Grandmamma has always treated me like an infant, you know. When she finds out I can earn a living, perhaps she’ll have a little more respect for me.”

“I’m sure of it,” said Billie, climbing into the back seat as they drew up in front of the hotel. “It’s a dangerous thing,” she said to herself as she sank down upon the cushions, “to wish for a thing unless you really want it, because if your wish comes true, you are just as apt as not to unwish it, and then things are in a muddle.”