who left us so strangely before the close of the semester."

"Oh, Miss Cullam!"

"Foolish, am I?" laughed the teacher. "Well, I suppose so. You know all
about Maggie, do you?"

"No!" gasped Ruth.

Eagerly she explained to the mathematics teacher how the strange girl
had appeared at the Red Mill and why she had remained there. Miss Cullam
was no less excited than Ruth when she heard these particulars.

"I must tell Dr. Milroth this," Miss Cullam declared. "Say nothing about
it, Ruth Fielding. And she says her name is 'Maggie'? Of course!
Margaret Rolff. I believe that is who she is."

"But to go out to housework," Ruth said doubtfully.

"That doesn't matter. We must learn more about this Maggie. Say nothing
until I have spoken to Dr. Milroth again."

But if this was a clue to the identity and where-abouts of the girl who
had left Ardmore so abruptly the year before, Ruth learned something the
very next day that, unfortunately, put it quite beyond her ability to
discover further details in the matter.

A letter arrived from Aunt Alvirah and after reading it once through
Ruth hurried away to Miss Cullam with the surprising news it contained.

Maggie had left the Red Mill. Without any explanation save that she had
been sent for and must go, the strange girl had left Aunt Alvirah and
Uncle Jabez, and they did not know her destination. Ben, the hired man,
had driven her to the Cheslow railway station and she had taken an
eastbound train. Otherwise, nothing was known of the strange girl's
movements.

"Oh, my dear!" cried Miss Cullam. "I am certain, then, that she is
Margaret Rolff. Even Dr. Milroth has come to agree that it may be that
strange girl. I hoped there was a chance of learning what really became
of those missing examination papers--and, of course, the vase. But how
can we discover what became of them if the girl has disappeared again?"

"Well, it's a very strange thing, I am sure," Ruth admitted. "Of course,
I'll write the folks at the Red Mill that if Maggie--or whatever her
real name is--ever turns up there again, they must let me know at once."

"Yes, do," begged the teacher. "Now that the subject has come up again I
feel more disturbed than ever over those papers. _Were_ they lost, or
weren't they? My dear Ruth! you don't know how I feel about that
mystery. All these girls whom I think so highly of, are still under
suspicion."

"I hope nothing like that will happen this year, dear Miss Cullam,"