He turned and started back down the gulch, and then stopped suddenly.

He heard it again--shrill, prolonged, a call from somewhere; where, he could not determine because of the piled masses of earth and rock that flung the sound riotously here and there and confused him as to direction.
Then his own horse turned his head and looked toward the left, and answered the call.

From far off the strange horse made shrill reply.
Andy got down and began climbing the left-hand ridge on the run, tired as he was.

Not many horses ranged down in here--and he did not believe, anyway, that this was any range horse.

It did not sound like Silver, but it might be the pigeon-toed horse of Miss Allen.