That day, as the manner rather than the purpose of the Yaqui changed, so there seemed to be subtle differences in the others of the party. Gale himself lost a certain sickening dread, which had not been for himself, but for Mercedes and Nell, and Thorne and the rangers. Jim, good-natured again, might have been patrolling the boundary line. Ladd lost his taciturnity and his gloom changed to a cool, careless air. A mood that was almost defiance began to be manifested in Thorne. It was in Mercedes, however, that Gale marked the most significant change. Her collapse the preceding day might never have been. She was lame and sore; she rode her saddle sidewise, and often she had to be rested and helped; but she had found a reserve fund of strength, and her mental condition was not the same that it had been. Her burden of fear had been lifted. Gale saw in her the difference he always felt in himself after a few days in the desert. Already Mercedes and he, and all of them, had begun to respond to the desert spirit. Moreover, Yaqui's strange influence must have been a call to the primitive.

Thirty miles of easy stages brought the fugitives to another waterhold, a little round pocket under the heaved-up edge of lava. There was spare, short, bleached grass for the horses, but no wood for a fire. This night there was question and reply, conjecture, doubt, opinion, and conviction expressed by the men of the party. But the Indian, who alone could have told where they were, where they were going, what chance they had to escape, maintained his stoical silence. Gale took the early watch, Ladd the midnight one, and Lash that of the morning.

They day broke rosy, glorious, cold as ice. Action was necessary to make useful benumbed hands and feet. Mercedes was fed while yet wrapped in blankets. Then, while the packs were being put on and horses saddled, she walked up and down, slapping her hands, warming her ears. The rose color of the dawn was in her cheeks, and the wonderful clearness of desert light in her eyes. Thorne's eyes sought her constantly. The rangers watched her. The Yaqui bent his glance upon her only seldom; but when he did look it seemed that his strange, fixed, and inscrutable face was about to break into a smile. Yet that never happened. Gale himself was surprised to find how often his own glance found the slender, dark, beautiful Spaniard. Was this because of her beauty? he wondered. He thought not altogether. Mercedes was a woman. She represented something in life that men of all races for thousands of years had loved to see and own, to revere and debase, to fight and die for.

It was a significant index to the day's travel that Yaqui should keep a blanket from the pack and tear it into strips to bind the legs of the horses. It meant the dreaded choya and the knife-edged lava. That Yaqui did not mount Diablo was still more significant. Mercedes must ride; but the others must walk.

The Indian led off into one of the gray notches between the tumbled streams of lava. These streams were about thirty feet high, a rotting mass of splintered lava, rougher than any other kind of roughness in the world. At the apex of the notch, where two streams met, a narrow gully wound and ascended. Gale caught sight of the dim, pale shadow of a one-time trail. Near at hand it was invisible; he had to look far ahead to catch the faint tracery. Yaqui led Diablo into it, and then began the most laborious and vexatious and painful of all slow travel.

Once up on top of that lava bed, Gale saw stretching away, breaking into millions of crests and ruts, a vast, red-black field sweeping onward and upward, with ragged, low ridges and mounds and spurs leading higher and higher to a great, split escarpment wall, above which dim peaks shone hazily blue in the distance.

He looked no more in that direction. To keep his foothold, to save his horse, cost him all energy and attention. The course was marked out for him in the tracks of the other horses. He had only to follow. But nothing could have been more difficult. The disintegrating surface of a lava bed was at once the roughest, the hardest, the meanest, the cruelest, the most deceitful kind of ground to travel.

It was rotten, yet it had corners as hard and sharp as pikes. It was rough, yet as slippery as ice. If there was a foot of level surface, that space would be one to break through under a horse's hoofs. It was seamed, lined, cracked, ridged, knotted iron. This lava bed resembled a tremendously magnified clinker. It had been a running sea of molten flint, boiling, bubbling, spouting, and it had burst its surface into a million sharp facets as it hardened. The color was dull, dark, angry red, like no other red, inflaming to the eye. The millions of minute crevices were dominated by deep fissures and holes, ragged and rough beyond all comparison.