ll six were frantically digging, hoeing, chopping,
beating in a frenzy against the spread of the flames. In some manner the
fire had jumped the line. It might have been that early in the fight a
spark had lodged. As long as the darkness of night held down the
temperature, this spark merely smouldered. When, however, the rays of
the sun gathered heat, it had burst into flame.

This sun made all the difference in the world. Where, in the cool of the
night, the flames had crept slowly, now they leaped forward with a
fierce crackling; green brush that would ordinarily have resisted for a
long time, now sprang into fire at a touch. The conflagration spread
from a single point in all directions, running swiftly, roaring in a
sheet of fire, licking up all before it.

The work was fierce in its intensity. Bob, in common with the others,
had given up trying--or indeed caring--to protect himself. His clothes
smoked, his face smarted and burned, his skin burned and blistered. He
breathed the hot air in gasps. Strangely enough, he did not feel in the
least tired.

He did not need to be told what to do. The only possible defence was
across a rock outcrop. To right and left of him the other men were
working desperately to tear out the brush. He grubbed away trying to
clear the pine needles and little bushes that would carry the fire
through the rocks like so many powder fuses.

He had no time to see how the others were getting on; he worked on
faith. His own efforts were becoming successful. The fire, trying, one
after another, various leads through the rocks, ran out of fuel and
died. The infernal roaring furnace below, however, leaped ever to new
trial.

Then all at once Bob found himself temporarily out of the game. In
trying to roll a boulder out of the way, he caught his hand. A sharp,
lightning pain shot up his arm and into the middle of his chest. When he
had succeeded in extricating himself, he found that his middle finger
was squarely broken.

VI

Bob stood still for a moment, looking at the injured member. Charley
Morton touched him on the shoulder. When he looked up, the ranger
motioned him back. Casting a look of regret at his half-completed
defences, he obeyed. To his surprise he found the other four already
gathered together. Evidently his being called off the work had nothing
to do with his broken finger, as he had at first supposed.

"Well, I guess we'll have to fall back," said Morton composedly. "I