in was a clear, sunny day, and they lost no time in throwing every door and window wide open, so that they might have the full benefit of the light and fresh air.
"Here is the room in which he moved around the most," remarked Roger, gazing around earnestly. "But I can't say that I see anything unusual, do you?"
They were all searching around, and after a few minutes had passed Ben uttered a low cry and held up a small object, almost covered with dust and dirt.
"A class pin!" cried Dave. "We must see if we can find any more of them."
It was not long before Phil came upon two pins sticking on a board of a closet. Then Roger ran into the next room and, after a short hunt, uncovered a flat pasteboard box with several more of the class pins, each a bit tarnished by the dampness, but otherwise uninjured.
"He must have come for the pins," said Ben. "That solves the mystery of how they disappeared from Mr. Dale's possession."
"Here is a postage stamp!" ejaculated Phil, and held it up. "It's an old Gdrman issue," he added. "And here are half a dozen others, all evidently torn from a sheet. Boys, Shadow must have taken the doctor's collection!"
Dave said nothing to this, for he had discovered
