"No, of course, I'm not so silly! But it's often better to let well alone."
"Mrs. Trevellyan is still away, so Miss Birks couldn't ask her to have the bars taken down now," volunteered Betty Scott.
"So she is," exclaimed Gerda, with an air of relief.
"Ah! You're afraid of the ghost," repeated Rhoda. "I'm more inclined towards the burglar theory. In the circumstances, I think Miss Birks would be quite justified in making an investigation, even without Mrs. Trevellyan's permission."
"I shouldn't wonder myself if Miss Birks called in the police," said Betty Scott.
The girls were in a ferment of excitement over the affair. Deirdre and Dulcie felt that in view of yesterday's discovery they had a strong clue to the mystery. They hesitated as to whether they ought at once to tell Miss Harding, but, as Miss Birks was expected home within an hour or two, they decided it was better to wait till they could deliver their news at head-quarters.
Gerda, during the whole day, had been very abstracted and peculiar in her manner. She was nervous, starting at every sound, and seemed so preoccupied with her own thoughts that she often took no notice when spoken to.
"What's wrong with the Sphinx?" commented Deirdre. "She's absolutely obsessed."
"Yes, I can't make her out. She's disturbed in her mind. That's easy enough to see. There's something queer going on in this school. I hope she's not mixed up in it."
"We'd decidedly better watch her. After all that's happened before, one can't trust her in the least. Until Miss Birks is safely back in the house I feel we oughtn't to let Gerda out of our sight. Who knows what she may be going to do, or whom she's in league with?"