Survivors: Genesis of a Hero (1977) by John Eyers is the first and only sequel to Terry Nation's novel, Survivors and the only one of the two not based on events from the 1975-1978 BBC serial. It picks up directly where the previous book ended with Peter Grant having murdered his mother, whom he hadn't seen in five years, before he recognises her while stealing a trailer full of supplies.
The plague known as the Death left only a handful of the world's population alive and Britain half a decade later is a a land of overgrown fields and crumbling towns that is rapidly descending into tyranny and barbarism. Ironically, the teen-aged Peter's crime turns him into a cold-hearted killer ideally suited to survive and thrive in this new dark age. Deciding that the best way to remain alive is to join up with the most powerful group, Peter enlists in the army of the National Unity Force; a Communist movement led by former trade union leader Arthur Wormsley, who is bent on conquering the whole of Britain. Luckily, Peter is not only willing to kill anyone who stands in his way, but he is also a master with a throwing knife, a natural leader of men, and a tactical genius, so in short order he rises from recruit to Sergeant to Captain to General. True, he does this by crushing what remains of the independent peoples, but we're assured in the prologue that this is a story of Peter's redemption, so we're asked to be patient.
It's a good thing we have this assurance because that redemption is long in coming. The story keeps up a fair pace as we follow Peter's career, his entanglement in palace intrigues, and his involuntary affair with Lady Sarah Boyer–Wormsley's woman and self-proclaimed queen of England. Eyers presents us with a fairly straightforward story of Peter's rise to power and his increasing vulnerability as his star rises and he makes new, more powerful enemies. A nice touch is how Eyers contrasts this with the fate of Tom Price, the only other main character to carry over from the last book, whose path as a coward and congenital liar leaves him in a deepening state of uncertainty and terror.
Three quarters of the way through the book, Peter is now a general, Wormsley is assassinated, and our hero is on the run to Wales. It's at this point that Eyers throws us a plot twist that's more like falling into a completely different book. Up until now, the rules have been fairly clear, but once Peter passes into Wales, we've gone from science fiction into Tolkien. We discover that within ten years of civilisation's collapse the Welsh have reverted to an idealised Iron Age society complete with homespun clothes, bows and stone-tipped arrows. warrior princesses, mystic dwarfs filled with prophecies, stilted speech habits that include everyone speaking fluent Welsh Gaelic, and all of it coated with an ecumenical form of primitive Christianity that indicates that Eyers felt it was going too far to resurrect the Druids. It does not stop him from saying with a straight face that the Welsh have "eliminated evil".
One wonders what they did in their spare time.
It's also at this point that Eyers seems to have lost interest in his plot because with almost peremptory speed Peter murders Tom Price, manages to regain his soul, learns to fight for a cause rather than himself, defeats the NUF, wins the warrior princess and becomes warlord of Wales. The story doesn't so much end here as pause in expectation of the third novel that never came.
In all, Genesis of a Hero is a fair companion to Survivors. Eyers captures Nation's voice and he remains true to the setting and premises of the first book–at least until Tom Bombadil shows up, but it suffers along with the first novel from the problem of where to take the story next. Either it ends up as some nihilistic Lord of the Flies story where society crumbles and decays until the reader is left with a dark age romance set among the ruins of London or some order returns and it becomes a tale of slow reconstruction. Both are valid paths, but either would have meant ending one story and beginning another. Eyers tries to split the difference and marches off to the Shire. It's a problem, but it does illustrate an important fact; there are some stories that just naturally tend toward an end. If that is the case, then the author must bite the lead sinker and end the story or avoid it and turn the work into "The Adventures of So-and-So in Somewhere" with the story of a depopulated world reduced to a Mad Max backdrop. Or in the case of Eyers, Mad Hobbit.