"Sure it was!" replied George. "A blue serge! I noticed it
particularly because it wasn't much of a fit."

"Well, these are blue serge threads!" commented Will.

"That's right, too," admitted Sandy.

While the boys still stood at the second level they heard some one
moving down from the top. Will rushed around to the ladder and looked
up.

He could not see the face of the man who was climbing down, but he
could see that he did not wear a blue serge suit.

In a moment he called out to him, asking some trivial question
regarding the action of the pumps. When the man looked down he saw
that it was Canfield. The caretaker seemed surprised at finding the
boys at the second level. He kept on descending.

"Wait!" Will called. "Stop where you are!"

"But I've got to find out what's the matter with the machinery at the
bottom," the caretaker called out. "There's something wrong there!"

"Then you'd better take long steps," replied Will, "for if you put any
weight on those rungs, you're likely to land at the bottom of the
shaft. The rungs have been cut!"

"I can't believe that!" replied Canfield.