"It startles me a good deal," confessed Edwards, grimly, "to think
what explanation I am to offer my mother."

"Oh, well, it _must_ turn up," replied Dr. Thornton, though vaguely.
"Anyway, Edwards, there has been no theft. The door is locked,
and the only two keys to it are the one carried by the monitor
and a duplicate which is kept locked in my own desk. You'll probably
find it in one of your pockets."

"I have been through every pocket in my clothes at least seven
times, sir," insisted the dismayed Edwards. "And that is a rather
valuable pin," he added; "worth, I believe, something, like fifty
dollars."

"Rest assured that we'll have some good explanation of the mystery
before long," replied the principal as soothingly as he could.

Edwards went away, sore and disheartened, but there was nothing
more to be said or done.

Thursday morning Dr. Thornton carried the investigation further,
but absolutely no light could be shed on the missing pin.

But at recess it was Frank Thompson who came upstairs breathless.

"Dr. Thornton," he cried, excitedly, "it's my own fault, of course,
but I'm afraid I've seen the last of my watch. It's one that
father carried for a good many years, and at last gave me. The
works are not very expensive, but the case was a gold one."