Both he and Jessup were conscious of a growing excitement as they neared the goal from which circumstances had held them back so long. Were they going to find out something definite at last? Or would fate thrust another unexpected obstacle in their way? Above all, if fortune proved kind, what would be the character of their discovery? Immensely intrigued and curious, Bud chattered constantly throughout the ride, suggesting all sorts of solutions of the problem, some of which were rather far-fetched. Gold was his favorite--as it has been the favorite lure for adventurers all down the ages--and he drew an entrancing picture of desert sands sprinkled with the yellow dust. He thought of other precious metals, too, and even gave a passing consideration to a deposit of diamonds or some other precious or semi-precious stones. Once he switched off oddly on the subject of prehistoric remains, and Stratton's surprised inquiry revealed the fact that three years ago he had worked for a party of scientific excavators in Montana. "Them bones and skeletons as big as houses bring a pile of money, believe me!" he assured his companion. "The country up there ain't a mite different from this, neither." Buck himself was unusually silent and abstracted. During the last ten days of enforced idleness he had considered the subject for hours at a time and from every conceivable angle, with the result that a certain possibility occurred to him and persisted in lingering in his mind, in spite of its seeming improbability. It was so vague and unlikely that he said nothing about it to Bud; but now, mounting the steep trail, the thought of it came back with gathering strength, and he wondered whether it could possibly be true. Advancing with every possible precaution, they gained the summit and passed on down the other side. Before them lay the desert, glittering and glowing in the morning sun, without a sign of alien presence. Keeping a sharp lookout, they reached the little, half-circular recess in the cliffs that formed the end of the trail, and paused. No rain had fallen in the last ten days and the print of motor-tires was almost as clear and unmistakable as the day it had been made. They could make out easily where the car had been driven in, the footprints about it, and the marks left by its turning; and with equal lack of difficulty they picked out the track made as it departed. The latter headed north, but Stratton was not interested in it. Without hesitation he selected the incoming trail, and the two followed it out into the desert. For a few hundred yards they rode almost due east. Then the wheel-marks turned abruptly to the south, and a little further on Buck noted the prints of a galloping horse beside them. "Lynch, I reckon," he commented, pointing them out to his companion. "When he saw me up on the cliffs down yonder, he must have hustled to catch up with the car."