underhand work at this
school. Now I want you cadets to do me a favor. I want you to act
exactly as if nothing out of the ordinary had occurred. I want you to
tell all of the others to keep quiet about this. I want to set a trap,
and if possible catch those rascals in the midst of their work. Do you
understand?"

"Yes, sir," came from both of the cadets.

"Then that is all."

Allowed to leave the office, Randy and Fred lost no time in hunting up
the others, who had gone upstairs to the Rover boys' rooms. On the way,
they met Walt, Spouter and Gif, and told these cadets to come along.
Then they closed the door to the hallway.

"It's to be kept a secret," announced Randy.

In subdued voices, so that no one passing in the hallway might hear
them, the Rovers and their chums discussed the situation. They were in
the midst of this when they suddenly heard a wild cry of alarm. Then
came a rush of footsteps, and less than a minute later the loud clanging
of a bell.

"Hello! what's that?" exclaimed Jack.

"Something is wrong--that's sure!" announced Randy.

"What's the bell ringing for?" queried Fred. "It isn't time for parade
yet."

"That isn't the parade bell!" ejaculated Gif. "That's the fire bell!
There must be a fire!"

The boys flung open the doors, and ran hastily into the hallway. Cadets
were pouring forth from every quarter, and there was a tremendous
excitement.

"Is the building on fire?"

"Take it easy, boys! Take it easy!" yelled Major Ralph Mason, as he
appeared at the head of one of the stairways. "There is no fire in this
building. Don't get excited."

"Where is the fire?" queried a dozen voices in chorus.

"It's down at the gym! The upper floor is in flames!"

CHAPTER XVI

PUTTING OUT THE FLAMES

"What do you know about that! The gym is on fire!" gasped Fred, and
clutched Randy by the arm. He looked at his cousin knowingly.

"I know what you're thinking, Fred. Those cigarettes that Slugger, Nappy
and Codfish were smoking----"

"That's it! They threw them down recklessly, and also threw down the
matches they had lighted."

"If the gym burns down Colonel Colby will hold them responsible for the
loss," put in Jack, who had heard what was said.

While this talk was taking place, all of the cadets were rushing down
the stairs. Soon they were out on the campus and headed through the
fast-falling snow in the direction of the gymnasium building.

A heavy smoke was pouring from a b