"In what direction?"

"It cuts the prairie from east to west."

"Well done, Frank, and who are these Indians?"

"As well as I can make out, they are Comanches."

The captain reflected a moment.

"Oh! it is some detachment of hunters," he said.

"Very likely," Frank replied.

The two men mounted.

"Frank and you, Kennedy," said the captain, at the expiration of a minute, "will go to the passage of the Buffalo, and encamp in the grotto which is there; carefully watching the movements of the Mexicans, but in such a manner as not to be discovered."

"Be satisfied of that, captain."