The Chrysalids is a science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 novel by John Wyndham

John Wyndham

John Wyndham Parkes Lucas Beynon Harris was an English science fiction writer who usually used the pen name John Wyndham, although he also used other combinations of his names, such as John Beynon and Lucas Parkes...

, first published in 1955 by Michael Joseph. It is the least typical of Wyndham's major novels, but regarded by some people as his best. An early manuscript was originally entitled Time for a Change.

The novel was adapted for BBC

BBC

The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...

 radio by Barbara Clegg in 1982 and for the theater by playwright David Harrower in 1999.
A few thousand years in the future post-apocalypse rural

Rural

Rural areas or the country or countryside are areas that are not urbanized, though when large areas are described, country towns and smaller cities will be included. They have a low population density, and typically much of the land is devoted to agriculture...

 Labrador

Labrador

Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...

 has become a warmer and more hospitable place than it is at present.