For some moments his ascent through the wet snow was slow and difficult, but as he advanced, he felt a change of temperature corresponding to that he had experienced that afternoon on the wagon coming down.  The air grew keener, the snow drier and finer.  He kept a sharp lookout for the moving figures, and scanned the horizon for some indication of the prospector’s deserted hut.  Suddenly the line of figures he was watching seemed to be broken, and then gathered together as a group.  Had they detected him?  Evidently they had, for, as he had expected, one of them had been detached, and was now moving at right angles from the party towards the right.  With a thrill of excitement he urged his horse forward; the group was far to the left, and he was nearing the solitary figure.  But to his astonishment, as he approached the top of the slope he now observed another figure, as far to the left of the group as he was to the right, and that figure he could see, even at that distance, was not a Chinaman.  He halted for a better observation; for an instant he thought it might be the fugitive himself, but as quickly he recognized it was another man—­the deputy.  It was he whom the Chinaman had discovered; it was he who had caused the diversion and the dispatch of the vedette to warn the fugitive.  His own figure had evidently not yet been detected.  His heart beat high with hope; he again dashed forward after the flying messenger, who was undoubtedly seeking the prospector’s ruined hut and—­Trixit.

But it was no easy matter.  At this elevation the snow had formed a crust, over which the single Chinaman—­a lithe young figure—­skimmed like a skater, while Masterton’s horse crashed though it into unexpected depths.  Again, the runner could deviate by a shorter cut, while the horseman was condemned to the one half obliterated trail.  The only thing in Masterton’s favor, however, was that he was steadily increasing his distance from the group and the deputy sheriff, and so cutting off their connection with the messenger.  But the trail grew more and more indistinct as it neared the summit, until at last it utterly vanished.  Still he kept up his speed toward the active little figure—­which now seemed to be that of a mere boy—­skimming over the frozen snow.  Twice a stumble and flounder of the mustang through the broken crust ought to have warned him of his recklessness, but now a distinct glimpse of a low, blackened shanty, the prospector’s ruined hut, toward which the messenger was making, made him forget all else.  The distance was lessening between them; he could see the long pigtail of the fugitive standing out from his bent head, when suddenly his horse plunged forward and downward.  In an awful instant of suspense and twilight, such as he might have seen in a dream, he felt himself pitched headlong into suffocating depths, followed by a shock, the crushing weight and steaming flank of his horse across his shoulder, utter darkness, and—­merciful unconsciousness.