As Miss Thompson concluded, she looked over the roomful of girls who sat watching her with serious faces.  Which one of them was guilty?  Time alone would tell.

At recess that morning the subject of the play was for once forgotten in the excitement occasioned by the principal’s recent disclosure.  Groups of girls indignantly denied even the thought of such mischief.

“I don’t believe Miss Thompson would ever suspect us of any such thing,” remarked Jessica to her friends.

“Of course not, goose,” replied Grace.  “She knows us too well for that.”

But it was with a peculiar apprehension of something unpleasant that Grace answered a summons to the principal’s office just before school closed for the day.

“Grace,” she said, as the young girl entered the office, “were you in my office yesterday afternoon between half past one and a quarter of two?”

“Why, yes, Miss Thompson.  I came to ask permission to use the gymnasium, but you were out, so I came back and asked you just before school closed.”

“Yes, I remember that you did,” replied the principal.  “However, I want you to read this.”

Grace took the paper, looking rather perplexed, and read: 

“Ask Miss Harlowe what she was doing in your
office between half past one and a quarter of two
yesterday.”

“A passerby.”

“Why—­why——­” stammered Grace, her eyes growing large with wonder.  “I don’t understand.  I came here at that time, for I looked at the clock as I came in, but I was only here for a second.”

Then the truth dawned upon her.  “Why, Miss Thompson,” she cried, “you surely don’t think I tore up your essay?”

“No, Grace, I don’t,” replied the principal.  “But I believe that the one who wrote this note is the one who did do it, and evidently wishes to fasten the guilt upon you.  It looks to me as though we had a common enemy.  Do you recognize either the paper or the writing?”

“No,” replied Grace slowly, shaking her head.  “Vertical writing all looks alike.  The paper is peculiar.  It is note paper, but different from any I ever saw before.  It looks like——­”

She stopped suddenly, a shocked look creeping into her eyes.

“What is it, Grace?” said Miss Thompson, who had been closely watching her.

“I—­just—­had a queer idea,” faltered Grace.

“If you suspect any one, Grace, it is your duty to tell me,” said the principal.  “I cannot pass lightly over such a piece of wanton destruction.  To clear up this mystery, should be a matter of vital interest to you, too, as this letter is really an insinuation against you.”

Grace was silent.

“I am waiting for you, Grace,” said the principal.  “Will you do as I wish?”

The tears rushed to Grace’s eyes.  “Forgive me, Miss Thompson,” she said tremulously, “but I can tell you nothing.”

“You are doing wrong, Grace, in withholding your knowledge,” said the older woman rather sternly, “and I am greatly displeased at your stubbornness.  Ordinarily I would not ask you to betray any of your schoolmates, but in this instance I am justified, and you are making a serious mistake in sacrificing your duty upon the altar of school-girl honor.”