Now the Professor walked with a distinct limp, while his bare feet
seemed to pick up every sharp pebble in camp, all of which added to
his discomfort.

"I'd make a nice sort of scout," he muttered. "Everybody within a
mile of me would know I was coming even before I got started, I
guess--"

The Professor suddenly cut short his words, and crouched down close to
the ground. He thought he heard something ahead and a little to the
right of him.

"Who's there?" he demanded.

No answer being made to his inquiry, he gripped his gun more firmly
and crawled cautiously toward the spot where he thought he had heard
some one moving. The night was so dark that he could make nothing out
of the shadows about him, being obliged therefore to trust entirely to
his sense of hearing.

Now he was certain that some one was in camp who had no business
there, for the sound of footsteps was plainly borne to his
ears--cautious, catlike steps, as if the intruder were seeking to get
away without attracting attention.

The Professor, determined to capture the intruder, getting down on all
fours to avoid possible detection, made a wide detour so as to come up
behind where the fellow seemed to be at that moment. After much labor
he managed to reach the desired position.