But Warren gave him no heed. The next minute Tim was almost at his side. "I belave we're riding faster than the spalpeens," he added, glancing for the twentieth time to the rear, where the Sioux were forcing their horses to the utmost. They did not fire for some time after the opening volley, giving their whole attention to this run for life. That the capacities of the pursuing ponies varied was quickly apparent. Several began dropping to the rear, but more than half maintained their places near each other. It was hard to tell whether they were holding their own or gradually drifting back from the fugitives. The one hopeful fact was that as yet they were not gaining. Whether they would do so or lose ground must quickly appear. Tim Brophy now performed a deed as reckless as it was daring. He watched the rear more than did Warren, and was in the act of drawing up beside the latter, when he discovered that one of the Sioux was leading all the rest. He was fully a rod in advance, and what was more alarming than everything else, he was gaining, beyond question, on the fugitives. His horse had developed a burst of speed that no one anticipated. Rising to the sitting posture in the saddle, Tim brought his gun to his shoulder. "Don't do that!" admonished Warren. "You have no chance to hit him, and will cause Billy to lose ground." The Irishman made no reply; he was too much occupied with the act he had in mind. Furthermore, he noted that the buck whom he held in such fear was making ready to fire. But Tim was ahead of him, and, by one of those strange accidents which sometimes happen, he hit him so fair and hard that, with the invariable cry of his race when mortally hurt, he reeled sideways and fell to the ground, his horse, with a snort of alarm, circling off over the prairie far from his companions. [Illustration: TIM'S FORTUNATE SHOT.] Warren glanced around at the moment the gun was discharged and could hardly believe his own eyes. He knew the success was accidental, and hoped it would not encourage Tim to repeat the attempt. It was expected that the shot would serve as a check to the rest, and ordinarily it would have done so, but it produced not the slightest effect in that direction. Back of the fallen warrior, whose body rolled over and over in the snow, as it struck with a rebound, were more than half a dozen, with the others streaming after them. They gave no heed to their fallen leader, neither uttering any outcry nor firing in return, but pressing their ponies to the highest possible point. They were resolved upon capturing those fugitives and subjecting them to a punishment beside which shooting would be a mercy.