“I’ll go to the mine if you say so,” put in Felix Cottle. “I’m better acquainted around the place than any of you.”

“All right; go,” said the sheriff; and at once the guide turned back on the trail.

He soon came upon the boys, to whom he explained the situation. Gus wanted to return with him, but Oliver was for following Mr. Whyland; and so they went on, leaving Felix Cottle to ride on to the Aurora mine alone.

“If we hurry we can catch up with Mr. Whyland,” said Oliver. “Come, Gus; remember the chase is not likely to last long.”

“I’ll do my best!” cried the stout youth. “Look-out, Oliver!” he went on suddenly.

He dropped down on his horse’s back, and instinctively Oliver did the same. There were two reports, and a clipping through the leaves of the trees followed.

“My gracious, he’s firing on us!” gasped Gus. “We must try to keep out of sight.” And he shuddered so greatly that he almost fell from his saddle.

“To the left—where the bushes are thicker!” exclaimed Oliver.

He led the way; and hanging low behind his horse’s neck, Gus followed. Soon they were once again well screened.