ally, he could hardly blame Thad for asking such a question, because
at first it was next to impossible to determine whether it was a
four-footed creature, or a human being who, for some good reason, was
trying to make himself appear as small as possible.

But as Hugh continued to look he saw the other raise himself to his
full height, as though to take a cautious survey of his surroundings.
Then he knew that it was no canine prowling around to discover scraps
thrown aside by the carpenters working on the board fence, as they ate
their noon lunch.

"It's a human being all right, Thad," Hugh whispered, in such a low
tone that even the sharpest pair of ears going could never have caught
the sound ten feet away.

"Man, or boy, Hugh?" asked Thad, copying the example set by the other,
and even bending his head so that his lips might come closer to Hugh's
right ear.

"Can't make that out," he was told.

"But what in the wide world is he trying to do?" pursued Thad, his
curiosity now fully aroused, as the unknown again started to move
forward, pursuing the same strange cautious tactics as before.

"That's what we ought to find out," Hugh told him. "I don't like the
way he's sneaking around here. It looks as if he might be up to some
game."

"Oh! perhaps it's a tramp," suggested Thad, as the idea dawned upon his
brain.

"He may be meaning to break into the building, to sleep there to-night.
I wouldn't put it past a hobo to steal anything he could find left in
the lockers. Hugh, it's up to us to put a kink in his rope. Let's
chase after him before he disappears."

CHAPTER VII

CAUGHT IN THE ACT

"Hold on, Thad," continued Hugh, as he put a restraining hand on the
shoulder of his more impulsive chum, "we've got to be careful, or else
he'll learn how we're meaning to spy on him. Bend over, and do the
grand sneak act."

"He's headed straight for the building, Hugh!" breathed the other, as
he complied with the directions given by the one whom he was accustomed
to look upon in the light of a leader.

"That's right, and I guess he's meaning to crawl inside, if only he can
find a window that's been left unfastened. Steady now, Thad; he's
stopped under one right now!"

They continued to crouch there and watch what went on, their eyes glued
upon the dimly seen figure of the unknown. Greatly to the surprise of
Thad, the party stepped to one side, and seemed to be dragging back a
heavy plank, not of any v