This is a very good sci fi book coming out in the cold war era (1972). In a post-nuclear-world-war world, some children start exhibiting mutations including extra fingers and toes, and, most recently, ESP. To the survivors, any such changes are a damnation and a manifestation of evil, which must be purged (purged 'with extreme prejudice'). The ESP children communicate with each other but keep everything very secret since their 'deformities' aren't obvious, until they believe they find a chance of escape to a new land where they can be free to be themselves. There are others like them on the other side of the blast zone. It turns out they can be as brutal as their captors. ( )