"Sure," replied his comrade, immediately. "Why, I've been smelling smoke for more'n a whole minute now. And I'm following it up, foot by foot."
"Oh!" murmured Bob, taken aback by this intelligence.
"Don't say a word above your breath, Bob. Whoever it is can't be far away now. We may run in on 'em any minute, you know," and as if to emphasize the need of caution Frank drew his chum close while he whispered these words directly in his ear.
Bob did not make any verbal reply; but he gave the other's sleeve a jerk that was intended to tell Frank he understood, and would be careful. Then they moved along again.
It was no easy task making progress through the darkness, and over such rough grounds, without causing any sound. Bob found that he had almost to get down on his hands and knees and creep, in order to accomplish it. But his chum had not forgotten that he was new to this sort of business, and hence he gave Bob plenty of time.
Then Bob in turn began sniffing, and Frank knew that now he, too, had caught the trail-odor, which was constantly becoming stronger. Thus they were positive that while they moved forward they must be gradually drawing nearer the source of the smoke.
Another tug came at Frank's sleeve, at which signal he bent his head low so that his chum might say what he wanted in his ear.
"Sounds like voices!" whispered the excited Kentucky lad.
Frank gave a little affirmative grunt.
"Rustlers, maybe?" Bob went on.