In less than an hour, though the time seemed only a few moments to the excited Slone, Wildfire had been driven down toward the narrowing neck of the valley, and he had begun to run, to and fro, back and forth.

Any moment, then, Slone expected him to grow terrorized and to come tearing up toward the pass.
Wildfire showed evidence of terror, but he did not attempt to make the pass.

Instead he went at the right-hand slope of the valley and began to climb.

The slope was steep and soft, yet the stallion climbed up and up.

The dust flew in clouds; the gravel rolled down, and the sand followed in long streams.