It was hot down in the lowland.  The heat struck up, reflected from the sand.  But it was a March sun, and no more than pleasant to Slone.  The wind rose, however, and blew dust and sand in the faces of horse and rider.  Except lizards, Slone did not see any living things.

Miles of low greasewood and sparse yellow sage led to the first almost imperceptible rise of the valley floor on that side.  The distant cedars beckoned to Slone.  He was not patient, because he was on the trail of Wildfire; but, nevertheless, the hours seemed short.

Slone had no past to think about, and the future held nothing except a horse, and so his thoughts revolved the possibilities connected with this chase of Wildfire.  The chase was hopeless in such country as he was traversing, and if Wildfire chose to roam around valleys like this one Slone would fail utterly.  But the stallion had long ago left his band of horses, and then, one by one his favorite consorts, and now he was alone, headed with unerring instinct for wild, untrammeled ranges.  He had been used to the pure, cold water and the succulent grass of the cold desert uplands.  Assuredly he would not tarry in such barren lands as these.

For Slone an ever-present and growing fascination lay in Wildfire’s clear, sharply defined tracks.  It was as if every hoof-mark told him something.  Once, far up the interminable ascent, he found on a ridge-top tracks showing where Wildfire had halted and turned.

“Ha, Nagger!” cried Slone, exultingly.  “Look there!  He’s begun facin’ about.  He’s wonderin’ if we’re still after him.  He’s worried. . . .  But we’ll keep out of sight—­a day behind.”

When Slone reached the cedars the sun was low down in the west.  He looked back across the fifty miles of valley to the colored cliffs and walls.  He seemed to be above them now, and the cool air, with tang of cedar and juniper, strengthened the impression that he had climbed high.

A mile or more ahead of him rose a gray cliff with breaks in it and a line of dark cedars or pinyons on the level rims.  He believed these breaks to be the mouths of canyons, and so it turned out.  Wildfire’s trail led into the mouth of a narrow canyon with very steep and high walls.  Nagger snorted his perception of water, and the mustang whistled.  Wildfire’s tracks led to a point under the wall where a spring gushed forth.  There were mountain-lion and deer tracks also, as well as those of smaller game.

Slone made camp here.  The mustang was tired.  But Nagger, upon taking a long drink, rolled in the grass as if he had just begun the trip.  After eating, Slone took his rifle and went out to look for deer.  But there appeared to be none at hand.  He came across many lion tracks and saw, with apprehension, where one had taken Wildfire’s trail.  Wildfire had grazed up the canyon, keeping on and on, and he was likely to go miles in a night.  Slone reflected that as small as were his own chances of getting Wildfire, they were still better than those of a mountain-lion.  Wildfire was the most cunning of all animals—­a wild stallion; his speed and endurance were incomparable; his scent as keen as those animals that relied wholly upon scent to warn them of danger, and as for sight, it was Slone’s belief that no hoofed creature, except the mountain-sheep used to high altitudes, could see as far as a wild horse.