It was evident the Blackfeet had not anticipated hot pursuit, and so they had made little or no effort to hide their trail after passing across an arm of the lake.
The trail grew hotter and hotter, but night came on swiftly, and Old Rocks was forced to bend low and keep his eyes on the ground.
"Watch out ahead, boy," he directed. "I've got all I kin' tend ter in follerin' ther trail. Don't let us run plump onter ther varmints, fer they might take a notion ter wipe us out."
So Frank followed the guide, keeping his eyes to the front, and watching for danger.
Darker and darker it became. Rocks was forced to proceed more slowly, as there was danger of losing the trail entirely.
Finally he found it necessary to stop now and then and examine the ground thoroughly.
"We shall not overtake them before dark, shall we?" asked Frank, anxiously.
"Hard tellin'. Watch out. May run onter 'em any time."
When they halted again, Frank suddenly uttered a low cry of warning, caught hold of the man, and exclaimed:
"Look there!"