Two score of men, at least, Caswell could send out, and from the heights they could surely detect the coming of Barry and plant themselves in his way.

An ambush, a volley, would end this famous ride.
The hills came up on them swiftly, now, and if the men of Caswell failed in their duty it meant safety for the fugitive, because two miles beyond were the willows of the marshes and the fords across the Asper River.
There could only be two alternatives, since not a man showed on the hills.

Either they waited in ambush, or else they had mistaken the route along which Barry would come, and the latter was hardly possible.

With his glasses Mark Retherton scanned the hills anxiously and it was then that he saw the dark form of the wolf-dog skulking on before the outlaw.

He had watched Black Bart before this, of course, but never with suspicion until he noted the peculiar manner in which the animal skirted here and there through the rough ground, pausing on high places, weaving back and forth across the course of his master.
"Like a scout," thought Retherton.