The horses were restive. Nagger snorted a welcome. Evidently they had passed an uneasy night. Slone found lion tracks at the spring and in sandy places. Presently he was on his way up to the notch between the great wall and the plateau. A growth of thick scrub oak made travel difficult. It had not appeared far up to that saddle, but it was far. There were straggling pine trees and huge rocks that obstructed his gaze. But once up he saw that the saddle was only a narrow ridge, curved to slope up on both sides.
Straight before Slone and under him opened the cañon, blazing and glorious along the peaks and ramparts, where the rising sun struck, misty and smoky and shadowy down in those mysterious depths.
It took an effort not to keep on gazing. But Slone turned to the grim business of his pursuit. The trail he saw leading down had been made by Indians. It was used probably once a year by them; and also by wild animals, and it was exceedingly steep and rough. Wildfire had paced to and fro along the narrow ridge of that saddle, making many tracks, before he had headed down again. Slone imagined that the great stallion had been daunted by the tremendous chasm, but had finally faced it, meaning to put this obstacle between him and his pursuers. It never occurred to Slone to attribute less intelligence to Wildfire than that. So, dismounting, Slone took Nagger's bridle and started down. The mustang with the pack was reluctant. He snorted and whistled and pawed the earth. But he would not be left alone, so he followed.
The trail led down under cedars that fringed a precipice. Slone was aware of this without looking. He attended only to the trail and to his horse. Only an Indian could have picked out that course, and it was cruel to put a horse to it. But Nagger was powerful, sure-footed, and he would go anywhere that Slone led him. Gradually Slone worked down and away from the bulging rim wall. It was hard, rough work, and risky because it could not be accomplished slowly. Brush and rocks, loose shale and weathered slope, long, dusty inclines of yellow earth, and jumbles of stone—these made bad going for miles of slow, zigzag trail down out of the cedars. Then the trail entered what appeared to be a ravine.
That ravine became a cañon. At its head it was a dry wash, full of gravel and rocks. It began to cut deep into the bowels of the earth. It shut out sight of the surrounding walls and peaks. Water appeared from under a cliff and, augmented by other springs, became a brook. Hot, dry, and barren at its beginning, this cleft became cool and shady and luxuriant with grass and flowers and amber moss with silver blossoms. The rocks had changed color from yellow to deep red. Four hours of turning and twisting, endlessly down and down, over bowlders and banks and every conceivable roughness of earth and rock, finished the pack mustang; and Slone mercifully left him in a long reach of cañon where grass and water never failed. In this place Slone halted for the noon hour, letting Nagger have his fill of the rich grazing. Nagger's three days in grassy upland, despite the continuous travel by day, had improved him. He looked fat, and Slone had not yet caught the horse resting. Nagger was iron to endure. Here Slone left all the outfit except what was on his saddle, and the sack containing the few pounds of meat and supplies, and the two utensils. This sack he tied on the back of his saddle, and resumed his journey.
Presently he came to a place where Wildfire had doubled on his trail and had turned up a side cañon. The climb out was hard on Slone, if not on Nagger. Once up, Slone found himself upon a wide, barren plateau of glaring red rock and clumps of greasewood and cactus. The plateau was miles wide, shut in by great walls and mesas of colored rock. The afternoon sun beat down fiercely. A blast of wind, as if from a furnace, swept across the plateau, and it was laden with red dust. Slone walked here, where he could have ridden. And he made several miles of up-and-down progress over this rough plateau. The great walls of the opposite side of the cañon loomed appreciably closer. What, Slone wondered, was at the bottom of this rent in the earth? The great desert river was down there, of course, but he knew nothing of it. Would that turn back Wildfire? Slone thought grimly how he had always claimed Nagger to be part fish and part bird. Wildfire was not going to escape.
By and by only isolated mescal plants with long, yellow-plumed spears broke the bare monotony of the plateau. And Slone passed from red sand and gravel to a red, soft shale, and from that to hard, red rock. Here Wildfire's tracks were lost, the first time in seven weeks. But Slone had his direction down that plateau with the cleavage lines of cañons to right and left. At times Slone found a vestige of the old Indian trail, and this made him doubly sure of being right. He did not need to have Wildfire's tracks. He let Nagger pick the way, and the horse made no mistake in finding the line of least resistance. But that grew harder and harder. This bare rock, like a file, would soon wear Wildfire's hoofs thin. And Slone rejoiced. Perhaps somewhere down in this awful chasm he and Nagger would have if out with the stallion. Slone began to look far ahead, beginning to believe that he might see Wildfire. Twice he had seen Wildfire, but only at a distance. Then he had resembled a running streak of fire, whence his name, which Slone had given him.
This bare region of rock began to be cut up into gullies. It was necessary to head them or to climb in and out. Miles of travel really meant little progress straight ahead. But Slone kept on. He was hot and Nagger was hot, and that made hard work easier. Sometimes on the wind came a low thunder. Was it a storm or an avalanche slipping or falling water? He could not tell. The sound was significant and haunting.
Of one thing he was sure—that he could not have found his back trail. But he divined he was never to retrace his steps on this journey. The stretch of broken plateau before him grew wilder and bolder of outline, darker in color, weirder in aspect and progress across it grew slower, more dangerous. There were many places Nagger should not have been put to—where a slip meant a broken leg. But Slone could not turn back. And something besides an indomitable spirit kept him going. Again the sound resembling thunder assailed his ears, louder this time. The plateau appeared to be ending in a series of great capes or promontories. Slone feared he would soon come out upon a promontory from which he might see the impossibility of further travel. He felt relieved down in the gullies, where he could not see far. He climbed out of one, presently, from which there extended a narrow ledge with a slant too perilous for any horse. He stepped out upon that with far less confidence than Nagger. To the right was a bulge of low wall, and a few feet to the left a dark precipice. The trail here was faintly outlined, and it was six inches wide and slanting as well. It seemed endless to Slone, that ledge. He looked only down at his feet and listened to Nagger's steps. The big horse trod carefully, but naturally, and he did not slip. That ledge extended in a long curve, turning slowly away from the precipice, and ascending a little at the further end. Slone drew a deep breath of relief when he led Nagger up on level rock.
Suddenly a strange yet familiar sound halted Slone, as if he had been struck. The wild, shrill, high-pitched, piercing whistle of a stallion! Nagger neighed a blast in reply and pounded the rock with his iron-shod hoofs. With a thrill Slone looked ahead.