This was my favorite John Wyndham story until The Midwich Cuckoos. The Chrysalids is a story set in a dystopian future around a coastal area of Canada (I think) The people struggle to live in a post apocalyptic world. They have regressed back in time and live like the old Pilgrim Fathers of America. They farm and ride about on horses and are deeply religious. The society is of an extreme christian and fundamental belief. They indoctrinate all that God sent tribulation because the old people were evil and made atomic bombs and machines - things that were abominations.
When babies are born, they are strictly examined to make sure there is no mutation upon the infant's anatomy. If there is, the child is taken to the fringes away from the Good lands. Here the mutant infant, if it survives, is brought up by the Outcast mutants.
Into this fundamental Christian society, a group of infants slip through the net. They are not normal but have no physical defects. Yet they are telepathic. It is something they must keep secret or risk being outcast and sent to the Fringes among the mutants where the girls are wickedly sterilised before being sent away.
It is a moving and very clever story with some great and very tense moments. I can't think why it has never been made into a film.