It was rough work for them; it was terrible work for the horses. Blanco Diablo refused to answer to the power of the Yaqui. He balked, he plunged, he bit and kicked. He had to be pulled and beaten over many places. Mercedes's horse almost threw her, and she was put upon Blanco Sol. The white charger snorted a protest, then, obedient to Gale's stern call, patiently lowered his noble head and pawed the lava for a footing that would hold.

The lava caused Gale toil and worry and pain, but he hated the choyas. As the travel progressed this species of cactus increased in number of plants and in size. Everywhere the red lava was spotted with little round patches of glistening frosty white. And under every bunch of choya, along and in the trail, were the discarded joints, like little frosty pine cones covered with spines. It was utterly impossible always to be on the lookout for these, and when Gale stepped on one, often as not the steel-like thorns pierced leather and flesh. Gale came almost to believe what he had heard claimed by desert travelers--that the choya was alive and leaped at man or beast. Certain it was when Gale passed one, if he did not put all attention to avoiding it, he was hooked through his chaps and held by barbed thorns. The pain was almost unendurable. It was like no other. It burned, stung, beat--almost seemed to freeze. It made useless arm or leg. It made him bite his tongue to keep from crying out. It made the sweat roll off him. It made him sick.

Moreover, bad as the choya was for man, it was infinitely worse for beast. A jagged stab from this poisoned cactus was the only thing Blanco Sol could not stand. Many times that day, before he carried Mercedes, he had wildly snorted, and then stood trembling while Gale picked broken thorns from the muscular legs. But after Mercedes had been put upon Sol Gale made sure no choya touched him.

The afternoon passed like the morning, in ceaseless winding and twisting and climbing along this abandoned trail. Gale saw many waterholes, mostly dry, some containing water, all of them catch-basins, full only after rainy season. Little ugly bunched bushes, that Gale scarcely recognized as mesquites, grew near these holes; also stunted greasewood and prickly pear. There was no grass, and the choya alone flourished in that hard soil.

Darkness overtook the party as they unpacked beside a pool of water deep under an overhanging shelf of lava. It had been a hard day. The horses drank their fill, and then stood patiently with drooping heads. Hunger and thirst appeased, and a warm fire cheered the weary and foot-sore fugitives. Yaqui said, "Sleep." And so another night passed.

Upon the following morning, ten miles or more up the slow-ascending lava slope, Gale's attention was called from his somber search for the less rough places in the trail.

"Dick, why does Yaqui look back?" asked Mercedes.

"Every little while," replied Mercedes.