the next algebra test. Sluper, we've a thief right
here in Rally Hall."

"I'd be sorry to think that, sir," said the dismayed janitor. "I can't
think of any of the boys who might do such a thing."

"But some one of them did, just the same," replied the professor. "See
here," and he showed the janitor the shaving of wax.

"That proves that it was all planned beforehand," he said. "An outside
thief would have had a skeleton key, or simply pried it open with a
jimmy. But somebody has taken a wax impression of the lock and had a key
made to fit.

"Keep this thing perfectly quiet for a time," the teacher cautioned. "Be
on the watch for anything suspicious you may see or hear among the boys.
And I want you to go down town to Kelly's, the locksmith. Get into a
talk with him, and bring the conversation round to the subject of
duplicate keys, and how they're made. If he's done anything of that kind
lately, he may drop a hint of it. He'd have no reason to keep quiet, for
he's an honest man and wouldn't do a crooked thing. If he's made such a
key, the thief has given him some plausible reason for getting it made.
Find out anything you can, and let me know at once. But, above all
things, don't let the matter get out."

The janitor, badly confused, went away on his mission, while Professor
Raymond sought out Dr. Rally to lay the matter before him. If it had
been an ordinary case, he would have acted on his own discretion. But
this was altogether too serious, involving as it did the good name of
one of the scholars, and, to a certain extent, the reputation of the
school itself.

He found the doctor in his office, and laid the matter before him,
giving him all the details that he knew himself and telling of his
instructions to the janitor.

Dr. Rally was white hot with amazement and indignation.

"The rascal shall suffer for it if we catch him!" he announced, with a
grimness that would have delighted Aaron Rushton and confirmed him in
his admiration for the doctor's sternness. "I'll dismiss him. I'll
disgrace him. I'll make such an example of him that nothing of the kind
will ever happen in this school again."

His eyes flashed under his shaggy brows, and the fist he brought down on
the desk clenched till the knuckles showed white.

"But what could have been the motive?" he asked, as he grew more
composed. "Of course, we can understand why some one might want to know
the questions that were going to be asked. But why did t