"I am afraid, Roger, that in such a case our hope of escape will be very small," said my uncle in a grave tone.  "Unless we can find water in some hollow in which it will be possible to conceal ourselves, at the return of day, the Indians are sure to see us.  Should they cross our track, they are equally certain to come upon us before long.  We must, however, hope for the best.  Go forward as you propose, and may Heaven protect you, my boy."