Pick of the paperbacks; The Breaking of Northwall, by Paul O. Williams. New York: Ballantine Books. $2 .25.

Hundreds of years after World War III the survivors' descendents live in small fierce tribes along what used to be the Mississippi River. Jestak the Pelbar is a man without a country, exiled from Pelbarigan society to spend a year doing menial labor in distant Northwall. But Jestak has a secret and a dream: to unite a broken world.

Blind suppression by one tribe and attacks by another could destroy the delicate balance of life that remains. But ecounters with Jestak change the view that the different tribes have of themselves and their land and, consequently, the course of their tiny world.

Williams has created a world of unique vision that carries the reader along in this fastpaced, enjoyable adventu re story.