The Professor straightened up to listen. He must be close upon the
other by this time. But what was his chagrin to hear those same
footsteps on the opposite side of the camp. Professor Zepplin by much
effort had just come from the other side himself.

"Stupid!" he muttered. "I'll take no roundabout way this time. I'll
go straight ahead and be as quiet about it as I can."

He did so. He moved straight across the camp ground, not forgetting
the saddle which he carefully avoided, but narrowly missing falling
over it a second time.

By the time he had crossed to his former position, the intruder had
done likewise. Professor Zepplin dodged behind a tree.

By this time the scientist was beginning to feel a little worried. He
could not understand what the other fellow's object might be. If it
were robbery, the fellow certainly would desire to get away as quickly
as possible, rather than remain when he knew that efforts were being
made to capture him. If not plunder, what could be his purpose?

With suddenly formed determination, Professor Zepplin strode out from
his hiding place, starting for the other side on a run.

The other man did the same, and the only result of the move was that
their positions were exchanged.

Once more the Professor decided to try strategy and see if he could
not come up behind his opponent.