demand on the horses was no
longer in evidence. He lost no time, but he did not hasten. His
course wound between low cinder dunes which limited their view of the
surrounding country. These dunes finally sank down to a black floor as
hard as flint with tongues of lava to the left, and to the right the
slow descent into the cactus plain. Yaqui was now traveling due west.
It was Gale's idea that the Indian was skirting the first sharp-toothed
slope of a vast volcanic plateau which formed the western half of the
Sonora Desert and extended to the Gulf of California. Travel was slow,
but not exhausting for rider or beast. A little sand and meager grass
gave a grayish tinge to the strip of black ground between lava and
plain.

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 waterhole,
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.

The day broke rosy, glorious, cold as ice. Action was necessary