"The whole blamed mountain's afire!" That, of course, was exaggeration, but Jack was scared.
Out again on the rock, he swept the slope beneath him with his telescope.

He could not see anything of the girl, and the swirling smoke filled him with a horror too great for any clear thought.

He climbed down and began running down the pack trail like one gone mad, never stopping to wonder what he could do to save her; never thinking that he would simply be sharing her fate, if what he feared was true--if the flames swept over that slope.
He stumbled over a root and fell headlong, picked himself up and went on again, taking great leaps, like a scared deer.

She was down there.
And when the fire struck that manzanita it would just go _swoosh_ in every direction at once....

And so he, brave, impulsive young fool that he was, rushed down into it as though he were indeed a god and could hold back the flames until she was safe away from the place..