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.  “It’s got away from us.”

Without further comment he shouldered his implements and took his way up the hill.  Bob handed his hoe and rake to Jack Pollock.

“Carry ’em a minute,” he explained.  “I hurt my hand a little.”

As he walked along he bound the finger roughly to its neighbour, and on both tied a rude splint.

“What’s up?” he muttered to Jack, as he worked at this.

“I reckon we must be goin’ to start a fire line back of the next cross-bridge somewheres,” Jack ventured his opinion.

Bob stopped short.

“Then we’ve abandoned the old one!” he exclaimed.

“Complete,” spoke up Ware, who overheard.

“And all the work we’ve done there is useless?”

“Absolutely.”