The odor grew stronger, but so interested was he in his labor that he did not at once understand the significance of his discovery.
"W-h-o-o-e-e!"
It was a long-drawn, warning shout.
"It's a signal!" exclaimed the lad, straightening up. "I wonder what's the matter?"
As he looked toward the camp a great wall of flame seemed to leap from the ground between him and his companions. There it poised for one brief instant, then, with a roar swooped down into the tall bunch grass, rushing roaring and crackling toward him.
For an instant he stood unbelieving, then the truth dawned upon him.
"The prairie's on fire!" cried Tad.
CHAPTER XII
THE DASH FOR LIFE
The shouts of the Pony Rider Boys and of the guide were swallowed up in the roar of the flames.