Wildfire had sunk deep before reaching the edge.  Manifestly he had lunged the last few feet.  Slone found a better place, and waded in, urging Nagger.  The big horse plunged, almost going under, and began to swim.  Slone kept up-stream beside him.  He found, presently, that the water was thick and made him tired, so it was necessary to grasp a stirrup and be towed.  The river appeared only a few hundred feet wide, but probably it was wider than it looked.  Nagger labored heavily near the opposite shore; still, he landed safely upon a rocky bank.  There were patches of sand in which Wildfire’s tracks showed so fresh that the water had not yet dried out of them.

Slone rested his horse before attempting to climb out of that split in the rock.  However, Wildfire had found an easy ascent.  On this side of the canyon the bare rock did not predominate.  A clear trail led up a dusty, gravelly slope, upon which scant greasewood and cactus appeared.  Half an hour’s climbing brought Slone to where he could see that he was entering a vast valley, sloping up and narrowing to a notch in the dark cliffs, above which towered the great red wall and about that the slopes of cedar and the yellow rim-rock.

And scarcely a mile distant, bright in the westering sunlight, shone the red stallion, moving slowly.

Slone pressed on steadily.  Just before dark he came to an ideal spot to camp.  The valley had closed up, so that the lofty walls cast shadows that met.  A clump of cottonwoods surrounding a spring, abundance of rich grass, willows and flowers lining the banks, formed an oasis in the bare valley.  Slone was tired out from the day of ceaseless toil down and up, and he could scarcely keep his eyes open.  But he tried to stay awake.  The dead silence of the valley, the dry fragrance, the dreaming walls, the advent of night low down, when up on the ramparts the last red rays of the sun lingered, the strange loneliness—­these were sweet and comforting to him.

And that night’s sleep was as a moment.  He opened his eyes to see the crags and towers and peaks and domes, and the lofty walls of that vast, broken chaos of canyons across the river.  They were now emerging from the misty gray of dawn, growing pink and lilac and purple under the rising sun.

He arose and set about his few tasks, which, being soon finished, allowed him an early start.

Wildfire had grazed along no more than a mile in the lead.  Slone looked eagerly up the narrowing canyon, but he was not rewarded by a sight of the stallion.  As he progressed up a gradually ascending trail he became aware of the fact that the notch he had long looked up to was where the great red walls closed in and almost met.  And the trail zigzagged up this narrow vent, so steep that only a few steps could be taken without rest.  Slone toiled up for an hour—­an age—­till he was wet, burning, choked, with a great weight on his chest.  Yet still he was only half-way up that awful break