This is the least typical of Wyndham’s novels in that it is set in the far future and not in middle England.
This is a tale of a small agricultural community on the island of Labrador in a far future post-apocalyptic world. Their historical documents refer to the people of old who were destroyed by “tribulation”, punishment from God for their sins.
Based on small-town America of the old west and religious values that we might identify today as fundamentalist, these people are fiercely insular and intolerant of difference. This rigid adherence to purity leads them every year to destroy a good proportion of their food crop. People who are different are killed or sterilised and banished into the wilderness.
When young David starts to have vivid dreams of big cities and horseless carriages and a group of his friends realise they are telepathic, they conspire to keep their abilities secret. Eventually they are discovered and flee to the fringes where they make contact with a far off civilisation.
It is not made explicitly clear what the Tribulation was but tales of blackened glass in affected areas, illness that sounds like radiation poisoning amongst those who go there and the presence of mutation suggests nuclear holocaust (a theme present in several other Wyndam novels).
The message about humanity is mixed. Throughout the community of Waknuk is portrayed negatively: ignorant, barbaric and by destroying their food supply, self-destructing. Yet at the end the new arrival from Sealand who comes to Labrador in what sounds like a helicopter, states in no uncertain terms that the people of Labrador would never tolerate her people and that her people could never tolerate the intolerance of the people of Labrador. A poignant message for our time.
If we are not prepared to defend a tolerant society against the onslaught of the intolerant, then the tolerant will be destroyed, and tolerance with them – Karl Popper