The sombre story of a group of people in their fifties who face the fact that there is no younger generation coming to replace them; instead nature is rushing back to obliterate the disaster they have brought on themselves.This story presents a picture of an Earth where humanity has become sterile because of radiation from atomic testing in space, and an increasingly decrepit ageing population lives out its days amongst a burgeoning nature, reclaiming towns in a riot of vegetation and new animal life.