The Ends of the Circle, by Paul O. Williams, copyright 1981; Del Rey/Ballantine Books, April 1981; ISBN 0-345-29551-X. Book Two of The Pelbar Cycle
This was the book in the series that I read first, many years ago. I'm in the process of rereading the series in order for the first time.
Random musings on books, code, and tabletop games.