His mount was a beautiful black mustang with three white feet, a white spot on his nose, and a mane that swept to his knees.  “His name’s Nack-yal,” Withers had said.  “It means two bits, or twenty-five cents.  He ain’t worth more.”  To look at Nack-yal had pleased Shefford very much indeed, but, once upon his back, he grew dubious.  The mustang acted queer.  He actually looked back at Shefford, and it was a look of speculation and disdain.  Shefford took exception to Nack-yal’s manner and to his reluctance to go, and especially to a habit the mustang had of turning off the trail to the left.  Shefford had managed some rather spirited horses back in Illinois; and though he was willing and eager to learn all over again, he did not enjoy the prospect of Lake and Withers seeing this black mustang make a novice of him.  And he guessed that was just what Nack-yal intended to do.  However, once up over the hill, with Kayenta out of sight, Nack-yal trotted along fairly well, needing only now and then to be pulled back from his strange swinging to the left off the trail.

The pack-train traveled steadily and soon crossed the upland plain to descend into the valley again.  Shefford saw the jagged red peaks with an emotion he could not name.  The canyon between them were purple in the shadows, the great walls and slopes brightened to red, and the tips were gold in the sun.  Shefford forgot all about his mustang and the trail.

Suddenly with a pound of hoofs Nack-yal seemed to rise.  He leaped sidewise out of the trail, came down stiff-legged.  Then Shefford shot out of the saddle.  He landed so hard that he was stunned for an instant.  Sitting up, he saw the mustang bent down, eyes and ears showing fight, and his forefeet spread.  He appeared to be looking at something in the trail.  Shefford got up and soon saw what had been the trouble.  A long, crooked stick, rather thick and black and yellow, lay in the trail, and any mustang looking for an excuse to jump might have mistaken it for a rattlesnake.  Nack-yal appeared disposed to be satisfied, and gave Shefford no trouble in mounting.  The incident increased Shefford’s dubiousness.  These Arizona mustangs were unknown quantities.

Thereafter Shefford had an eye for the trail rather than the scenery, and this continued till the pack-train entered the mouth of the Sagi.  Then those wonderful lofty cliffs, with their peaks and towers and spires, loomed so close and so beautiful that he did not care if Nack-yal did throw him.  Along here, however, the mustang behaved well, and presently Shefford decided that if it had been otherwise he would have walked.  The trail suddenly stood on end and led down into the deep wash, where some days before he had seen the stream of reddish water.  This day there appeared to be less water and it was not so red.  Nack-yal sank deep as he took short and careful steps down.  The burros and other mustangs were drinking, and