Besides, he had had a few minutes' start.

After all, he might have been at the rapid and have hurried back in order to deceive the man who had disturbed him.
Moreover, he had learned who the man was.
This, however, did not take Thirlwell far and he resumed his walk, wondering what Driscoll had been doing and why he feared to be disturbed.

It was plain that he had taken some trouble to put Thirlwell off the track and might have succeeded had not the hoarseness of his voice given the latter a hint.

Thirlwell felt puzzled, but could find no clue, and deciding that the matter was not important presently dismissed it.

For all that, he resolved to watch Driscoll, but saw nothing to excite his suspicions for the next week or two.