Over the years, F. Paul Wilson's “Repairman Jack” series, most of whose early novels focused on their hero's helping crime victims, has increasingly gone back to the horror focus of The Tomb, the very first in the series. A Necessary End, a collaboration with British horror writer Sarah Pinborough not set in the Repairman Jack series, turns entirely to horror.

Horror fiction characteristically works by evoking various primal human fears: corpses, predatory animals, mutilation, rape, curses, and loss of self-command are all examples. The fears in A Necessary End are epidemiological and parasitological — that is, they focus on bodily decay and contagion. The vector of the contagion is portrayed in hard scientific detail; there's nothing obviously supernatural about it.

A further emphasis of this story is the disintegration of human societies under an overwhelming threat. We don't see a sudden total collapse, but a gradual failure of institutions such as the police and the National Health Service (the main setting is the United Kingdom). Most of the population attempts to accommodate itself to the new conditions, trying to minimize exposure to the threat and finding ways to provide for themselves as commerce and government shut down. Some of them have more extreme reactions, from mob violence to religious enthusiasm. There isn't any overt libertarian message to this story; it shows conditions under which any legal and political regime would break down.

The main character, Nigel, represents the effort to function normally. His career as a reporter gives him a view of the plague; after his return to England, he takes up a new story, about a vanished child, which drives much of the remaining plot. He encounters various people who have turned to religion either to protect them or to explain the plague, and responds to them in a rational, skeptical way. This drives the other major conflict, between Nigel and his wife Abby, a devout Catholic who sees God's will all around her — both in her own life and in the breakdown of human civilization — and hopes to bring Nigel to share her faith. An underlying theme of the story is theodicy, or how, in Milton's words, “to justify the ways of God to man.” This is the point at which the supernatural comes in: Not as crude, brute force miracles that overthrow or set aside the laws of nature, but as subtler ones that work within them to produce improbable outcomes.

Or so, at least, Abby believes. One of the strengths of the story is that, at the end, the reader is left to decide if she's right. Is this the story of an apocalypse brought about by divine intervention? Is it the story of a purely natural catastrophe whose survivors attribute it to divine intervention as a way of making sense of the unendurable? Pinborough and Wilson offer carefully balanced evidence for both sides, making the reader a participant in one of the world's oldest philosophical debates.