Here the ground opened up again, and they roved on at a free gallop, the black always half a length in front. In all the length of the mountain-desert there was no other picture which could compare with these two in their youth and their pride and their fearlessness.

They rode alert, high-headed like their horses, and there was about them a suggestion of the patience which carries a man endlessly after one purpose, and a suggestion of the eagerness, too, which makes him strike swift and hard and surely when the time for action comes.

Along the ridge of a crest, an almost level stretch of a mile or more, Jack eased the grip on the reins, and the black responded with a sudden lengthening of stride and lowered his head with ears pressed back flat while he fairly flew over the ground.

Nothing could match that speed. The strong mare fell to the rear, fighting gamely, but beaten by that effort of the stallion.

Jack swerved in the saddle and looked back, laughing her triumph. Pierre smiled grimly in response and leaned forward, shifting his weight more over the withers of Mary. He spoke to her, and one of her pricking ears fell back as if to listen to his voice. He spoke again and the other ear fell back, her neck straightened, she gave her whole heart to her work.

First she held the stallion even, then she began to gain. That was the meaning of those round, strong hips, and the breadth of the chest. She needed a half-mile of running to warm her to her work, and now the black came back to her with every leap.

The thunder of the approaching hoofs warned the girl. One more glance she cast in apprehension over her shoulder, and then brought her spurs into play again and again. Still the rush of hoofs behind her grew louder and louder, and now there was a panting at her side and the head of cream-colored Mary drew up and past.

She gave up the battle with a little shout of anger and slowed up her mount with a sharp pull on the reins. It needed only a word from Pierre and his mare drew down to a hand-gallop, twisting her head a little toward the black as if she called for some recognition of her superiority.

"It's always this way," cried Jack, and jerked at the reins with a childish impotence of anger. "I beat you for the first quarter of a mile and then this fool of a horse—I'm going to give him away."

"The black," said Pierre, assuming an air of quiet and superior knowing which always aggravated her most, "is a good second-rate cayuse when some one who knows horses is in the saddle. I'd give you fifty for him on the strength of his looks and keep him for a decoration."