For three days they went their way grimly into the parched sands, husbanding every particle of strength, within plain sight of each other, always at the same unvarying walk.  At night they slept by fits and starts, with an ear trained for the slightest hostile sound.  Then they cast aside their saddles, their rifles, and superfluous clothing, in a vain effort to save their mounts.

The horses, heaving and staggering, crawled over the yielding sands like silhouettes drawn by a thread.  In the sky not a cloud appeared; below, the yellow monotony extended as flat as a dish.  Above them a lazy buzzard, wheeling in languid circles, followed with patient conviction.

On the fourth morning Frawley’s horse stopped, shuddered, and went down in a heap.  Greenfield halted and surveyed his discomfiture grimly, without a sign of elation.

“That’s bad, very bad,” Frawley said judicially.  “I ought to have sent word to the department.  Still, it’s not over yet—­his horse won’t last long.  Well, I mustn’t carry much.”

He abandoned his revolver, a knife, $200 in gold, and continued on foot, preserving only the water-bag with its precious mouthful.  Greenfield, who had waited immovably, allowed him to approach within a quarter of a mile before putting his horse in motion.

“He’s going to make sure I stay here,” said Frawley to himself, seeing that Greenfield made no attempt to increase the lead.  “Well, we’ll see.”

Twelve hours later Greenfield’s horse gave out.  Frawley uttered a cry of joy, but the handicap of half a day was a serious one; he was exhausted, famished, and in the bag there remained only sufficient water to moisten his lips.

The fifth day broke with an angry sun and no sign on the horizon to relieve the eternal monotony.  Only the buzzard at the same distance aloft bided his time.  Hunter and hunted, united perforce by their common suffering, plodded on with the weary, hopeless straining of human beings harnessed to a plow, covering scarcely a mile an hour.  From time to time, by common consent, they sat down, gaunt, exhausted figures, eyeing each other with the instinct of beasts, their elbows on their bony knees.  Whether from a fear of losing energy, whether under the spell of the frightful stillness, neither had uttered a word.

Frawley was afire with thirst.  The desert entered his body with its dry mortal heat, and ran its consuming dryness through his veins; his eyes started from his face as the sun above him hung out of the parched sky.  He began to talk to himself, to sing.  Under his feet the sand sifted like the soft protest of autumn leaves.  He imagined himself back in the forest, marking the rustle of leafy branches and the intermittent dropping of acorns and twigs.  All at once his legs refused to move.  He stood still, his gaze concentrated on the figure of Greenfield a long moment, then his body crumpled under him and he sank without volition to the ground.