At last he stumbled, and stopped to keep himself from falling forward on his face.  He could go no further; his breath was spent; he was dripping with perspiration; his legs were trembling under him; there was a roaring in his ears; round red disks of the sun were scattered everywhere around him like spots of blood.  To the right of the trail there seemed to be a slight mound where he could rest awhile, and yet keep his watchful survey of the horizon.  But on reaching it he found that it was only a tangle of taller mesquite grass, into which he sank with his burden.  Nevertheless, if useless as a point of vantage, it offered a soft couch for Susy, who seemed to have fallen quite naturally into her usual afternoon siesta, and in a measure it shielded her from a cold breeze that had sprung up from the west.  Utterly exhausted himself, but not daring to yield to the torpor that seemed to be creeping over him, Clarence half sat, half knelt down beside her, supporting himself with one hand, and, partly hidden in the long grass, kept his straining eyes fixed on the lonely track.

The red disk was sinking lower.  It seemed to have already crumbled away a part of the distance with its eating fires.  As it sank still lower, it shot out long, luminous rays, diverging fan-like across the plain, as if, in the boy’s excited fancy, it too were searching for the lost estrays.  And as one long beam seemed to linger over his hiding-place, he even thought that it might serve as a guide to Silsbee and the other seekers, and was constrained to stagger to his feet, erect in its light.  But it soon sank, and with it Clarence dropped back again to his crouching watch.  Yet he knew that the daylight was still good for an hour, and with the withdrawal of that mystic sunset glory objects became even more distinct and sharply defined than at any other time.  And with the merciful sheathing of that flaming sword which seemed to have swayed between him and the vanished train, his eyes already felt a blessed relief.

CHAPTER III

With the setting of the sun an ominous silence fell.  He could hear the low breathing of Susy, and even fancied he could hear the beating of his own heart in that oppressive hush of all nature.  For the day’s march had always been accompanied by the monotonous creaking of wheels and axles, and even the quiet of the night encampment had been always more or less broken by the movement of unquiet sleepers on the wagon beds, or the breathing of the cattle.  But here there was neither sound nor motion.  Susy’s prattle, and even the sound of his own voice, would have broken the benumbing spell, but it was a part of his growing self-denial now that he refrained from waking her even by a whisper.  She would awaken soon enough to thirst and hunger, perhaps, and then what was he to do?  If that looked-for help would only come now—­while she still slept.  For it was part of his boyish