Brief as was the halt, it wrought a complete change of situation.

Whereas Fred had been in the greatest danger, Jack was now thus placed, because the grizzly was closer to him.
Not only that, but, ignoring the younger lad, he gave his whole attention to Jack.
Events were going with such a rush that the boys were almost overwhelmed before they could help themselves.

Fred supposed the bear was at his heels until, having run a couple of rods, he glanced over his shoulder and saw the imminent peril of Jack.

Then, with a thrill of alarm, he in his turn checked his flight, and bringing his Winchester to a level drove a bullet into the immense head of the brute, which by that time had received a respectable amount of lead in his carcass.
But "old Ephraim" seemed to have determined to dispose of the fugitives in the reverse order of their ages; that is to say, having changed his attentions to Jack Dudley, he did not mean to be diverted therefrom, even though the younger lad was showing disagreeable interest in him.
This peculiar turn of affairs gave Fred his favorable chance; and, standing motionless, he continued his miniature bombardment as fast as he could shove the cartridges into the chamber of his weapon, aim, and fire.

Surely the bullets, all of which found a lodgment somewhere in the anatomy of the monster, must have produced an effect, but they could not divert him from his main purpose.