He much preferred that they should all take care of themselves by giving their animals the rein and permitting the Apaches to make no nearer approach. But the scouts were obstinate and remained as motionless as statues. The tramping of myriad feet came nearer and nearer, until the sound partook of one general, thunderous undertone of the most trying character to the lad. It seemed to him so much like suicide--this waiting for a terrible danger as it steadily approached--that he was strongly tempted to start his horse away on his own account. "Look!" called out Morris, pointing toward the southwest. Following the direction indicated, the lad saw what appeared to be a heavy cloud lying low down in the horizon, but creeping slowly upward, like the sulphurous vapor that sometimes hovers over a battle field. "What is it?" he asked, terrified, knowing that it was not the presage of a storm such as sometimes sweeps over the prairies. There was something strange and unnatural in its appearance, accompanied, as it was, by the tremulous, thunderous rumbling. By and by, as this uproar came nearer and nearer, a still more curious sight presented itself. The prairie seemed agitated, trembling and quivering with a peculiar, wave-like motion, such as the ocean shows when it is subsiding after a severe storm. There was a sea, a living sea, spreading tumultuously over the plain. Dark, heaving masses were constantly verging nearer, as they moved rapidly toward the northeast. Suddenly light broke in upon the mind of Ned Chadmund. "I know what it is!" he exclaimed. "They are buffaloes." "Correct," assented Tom, with a laugh. "They are passing pretty close, but we're out of their way." The buffaloes surged so near to where the three horsemen stood that more than once Ned started with a fear that they would be overwhelmed; but the hunters showed such calmness and self-possession that he was reassured. All at once a furious trampling was heard, and two of the animals that had become separated from the others in some way, dashed directly by the horsemen and out upon the prairie. "Now, Ned," called out Tom; "there's your chance! Take that head one! He will make you a good supper if you can fetch him down!" The lad and his animal were seized with a sudden inspiration seemingly at the same time. Just as the heart of the young hunter swelled with a wild desire to bring down the noble game, the mustang bounded away in pursuit of the very buffalo which had been indicated by the trapper. As the rider saw himself drawing rapidly near the huge body, lumbering awkwardly but rapidly along, he was seized with a fluttering which, perhaps was natural, but which, unless overcome, was fatal to any hopes of procuring any supper. The mustang drew steadily nearer, Ned's agitation increasing every minute, until pursuer and pursued were running side by side.