“The world is on fire, I tell you!” Jimmie cried, presently. “That’s what Ned is shiftin’ about for. If the blaze wasn’t high up on the mountains we couldn’t see the columns of smoke over the rim of the valley.”

“Well,” Pat observed, “the fire can’t get in here. Nothing to burn.”

“It can fill the cup with hot air and scorch us to death,” Frank said, uneasily. “I think we’d better be looking about for a place to crawl into.”

“Wait until Ned comes,” Jimmie suggested. “He’ll know what to do.”

The aeroplane acted badly in the currents caused by the burning forest, but Ned finally managed to bring it down in the valley. The boys gathered about him, all excitement, and the steak à la brigand was for the moment forgotten in the joy at the return of the patrol leader and the anxiety to learn something of conditions out in the woods.

“It’s going to be a great conflagration,” Ned said, “but I think the aeroplane will be safe here. The whole slope is on fire.”

“I wouldn’t take chances on leaving it here,” Frank advised. “I’d jump over the divide with it.”

“I have been in the air three hours now,” Ned replied, “and must have a rest. Besides, we must remain where we can, if necessary, help head off the flames. That is what we are here for, remember.”

“Not to fight fires,” corrected Frank, “but to find out who sets them.”

“Anyhow,” Ned replied, “we must fight the fire, if it gives us a chance, now that we are here. Now, what do you think that is?” he added, as a chorus of howls and cries came up from the slope on the west.