Whilst a number of the stories in this series of three books have an installment in each volume, there are some solo stories, and this is one, although it has a feel for one story in a sequence.
Enid is on what she thinks will be her last case, in a landscape in which the big cities are distant, fading ruins, and rural communities are living together and off the land, paying close attention to sustainability, especially with reference to earning the right to have children. And it’s a transgression of this nature that Enid and her tyro assistant Bert (I kept wanting to read Bert and Ernie, rather than Bert and Enid) have to set out to investigation in their official role.
As such there isn’t much drama, a few conversations take place, and there is a resolution, but the story is about setting out one potential way for a small minority to re-establish humanity (and sfnally could easily have been set on a planet being settled, or in a generation starship with limited resources). The story ends in a way that suggests that End is will continue (and if this story had been in volume one, clearly sequels in volumes two and three would have been forthcoming).