Arden decided to try a new method of approach.

“Sim, I wouldn’t mention it if I didn’t want you to stay,” she said. “But you got us into this, even if you meant it all for the best, and even if you do leave, Terry and I will still be campused. There are lots of other things to do besides swimming, and, don’t forget, we have a mystery here that no one dreams about but us.”

“I am sorry about you and Terry, but right now I don’t feel like being a good sport. I’ll go to Tiddy and ask her to let you two off.” Sim hesitated. “But I want to go home, Arden. Don’t ask me to stay.”

“If you feel you must go, Sim, all right. But what I ask you to do is not to mail your letter for a few days. Write another in its place, at least temporarily, and say everything is settled. And then, if you still feel the same way——” Arden shrugged and turned aside.

Sim left her desk and walked slowly to a window. The peacefulness of the scene below, framed by the trees in their bright autumn array, must have had some influence on the perturbed girl. For, after a few moments of silent contemplation, Sim swung around and exclaimed:

“All right, Arden. I’ll think it over. You can hold this letter for three days, and I’ll write another to send home. But it’s only because of my friendship for you both that I’m doing it.”

“That’s great, Sim! You won’t be sorry. We’ll forget about it now and——”

A small shuffling noise stopped Arden in the midst of her exultation. It came from the direction of the door, and, even as the three looked, a bright blue and white envelope was pushed under the portal. Terry picked up the missive and opened it.

“Why!” she exclaimed in delighted surprise, “it’s an invitation for a party tomorrow in the gym. The sophomores are giving it to the freshmen, and we must,” she was rapidly reading the note, “all wear some sort of a costume. Oh, how precious!” She was gleefully excited.

“What fun!” With the suddenness of youth Arden closed her mind to the subject of Sim threatening to go home and she began to plan for the party.