The Chrysalids (United States title: Re-Birth) is a science fiction novel by British writer John Wyndham, first published in 1955 by Michael Joseph.

[8] The inhabitants of post-apocalypse Labrador have vague knowledge of the "Old People", a technologically advanced civilization they believe was destroyed when God sent "Tribulation" to the world to punish their forebears' sins.

The inhabitants practise a form of fundamentalist Christianity; they believe that to follow God's word and prevent another Tribulation, they must preserve absolute normality among the surviving humans, plants and animals, and therefore practice eugenics.

The government's position is considered both cynical and heretical by many of the orthodox frontier community, and it is suggested that they support the usage of these animals for the sole purpose of their greater efficiency.

The inland rural settlement of Waknuk is a frontier farming community, populated with hardy and pious individuals, and is where the story mainly takes place.

Later, Sophie's family attempts to escape from the reprisals (ceremonies in which blasphemies are sterilized) when her wet footprints are seen and reported by a local boy.

Though the nature of "Tribulation" is not explicitly stated, it is implied that it was a nuclear holocaust, both by the mutations and by the stories of sailors who report blackened, glassy wastes to the south-west where the ruins of faintly glowing cities can be seen (presumably the east coast of the US).

Rigo (Rigolet) is the capital of Labrador and the fictional government in the book, a fairly large river town near the east coast.

Later, the existence of geographic areas far less affected by the nuclear exchange and fallout are established, particularly Sealand (New Zealand), which is home to a socially and technologically advanced society where telepathy not only is the norm, but is encouraged and developed as a survival advantage.

"[13] Galaxy reviewer Groff Conklin praised the novel as "so skillfully done that the fact that it's not a shiny new idea makes absolutely no difference".

[15] Writing in Astounding, P. Schuyler Miller reported that Wyndham "has made the Mutant theme believable in a way that Odd John, Slan and the stories of the Baldies never quite were".

BBC Radio 4 Woman's Hour presented an unabridged reading by Geoffrey Wheeler of the novel in ten 15-minute episodes, broadcast daily between 17 and 28 August 1970.

The novel was adapted by Barbara Clegg as a single 90-minute drama for BBC Radio 4, directed by Michael Bartlett, and first broadcast on 24 April 1981.