In the not too distant future, a very smoggy and overpopulated Earth government makes it illegal to have children for a generation. One couple, unsatisfied with their substitute robot baby, breaks the rules and gets in a lot of trouble. (Z.P.G. stands for Zero Population Growth).
Reddleman Diggory Venn drives slowly across the heath, carrying a hidden passenger in the back of his van. When darkness falls, the country folk light bonfires on the hills, emphasizing the pagan spirit of the heath and its denizens.