I bought this book after reading the prequel novella that is available on Audible plus. The novella was very good in setting up an apocalyptic scenario that led to the emergence of a dystopian society.
This story picks up maybe 20 years later, well after the apocalypse and major social changes have occurred. It's the story of a man who hunts degenerates - those whose brains have been largely destroyed by a virus infection - after they have been deemed violent by the government. Degenerates are not quite zombies, and not necessarily violent, but the story is zombie-adjacent. The basic synopsis is that the main character and his partner make a serious mistake when killing degenerates, and find themselves in serious trouble. Most of the book is about them working to cover up their crime.
While I really enjoyed the novella prequel, I found this full-length book to be much weaker. It is exciting, and thus a fun read. But the worldbuilding is much weaker than I'd expect from a full-length novel developing a setting (fortunately, I read the novella first), the antagonists are such over-the-top bad guys, and the story relies on the main characters making pretty bad decisions at various points. And the twist at the end, which I won't spill, is so remarkably terrible (and completely nonsensical) that it ruined the book for me. Until that ending I'd have probably bought and read a sequel to this book, but after that ending I have no interest in reading any follow-up to this story (though no such sequel has been published yet).
Summary: The setting for the story is excellent but underdeveloped, I liked the main character, and the pace is quick and exciting, but the actual story is pretty shallow and the ending was rubbish.
I give this a 3 out of 5, enjoyed reading it enough to finish but not enough to recommend to others. I did the audiobook, and the reader is very good, a solid 4 or even 4.5 out of 5.
My personal rating scale: 5 (best of the genre, highly recommended); 4 (good book, recommend to others who like similar types of books); 3 (decent book, enjoyed reading it but not enough to recommend to others); 2 (has merit, but I didn't enjoy it much, and possibly didn't finish it); 1 (trash that shouldn't have been published).