The four men, heavily armed, and equipped for winter service, rode up the bank of the ravine to the irregularity of plain beyond. The trail, leading directly south into the solitudes, was easily followed, and Wasson, slightly in advance of the others, made no attempt to check his horse, content to lean forward, his keen eyes marking every sign. Scarcely a word was exchanged, since Hamlin had explained what had occurred as they crossed the river. Hardly less interested than the Sergeant, the sober-faced scout concentrated every energy on the pursuit, both men realizing the necessity of haste. Not only would the trail be difficult to follow after they attained the sand belt, but, if snow fell, would be utterly blotted out. And the dull, murky sky threatened snow, the sharp wind having already veered to the northwest. All about stretched a dull, dead picture of desolation, a dun-colored plain, unrelieved by vegetation, matching the skies above, extending in every direction through weary leagues of dismal loneliness. The searching eye caught no relief from desolate sameness, drear monotony. Nowhere was there movement, or, any semblance of life. Behind, the land was broken by ravines, but in every other direction it stretched level to the horizon, except that far off southward arose irregular ridges of sand, barren, ugly blotches, colorless, and forever changing formation under the beating of a ceaseless wind. It was desert, across which not even a snake crawled, and no wing of migrating bird beat the leaden sky above.