This must be one of the best debut novels. It is so much more than just a gory, apocalyptic end-of-world novel (though it successfully achieves that too). It is (very) dark and genuinely scary, but in places full of the blackest humour and some actual laugh out loud moments (when our heroine finds one other survivor after the complete annihilation of the population, it really shouldn't be funny, but honestly I laughed out loud). The story follows our female survivor partly in real time and partly in a series of flashbacks to explain her complex back stories, relationships and problematic behaviours. It is all handled very sympathetically and is crucial to understanding her personal challenges and developments.
This review won't use spoilers to mar the plot but we follow our survivor through some amazing, and disgusting (be warned) physical challenges, but equally important emotional and psychological challenges as she comes to grips with the possibility that she may be the only personal alive.
The end-of- the world sub genre is well established and until recently has often focused on nuclear armageddon (think Morrow's superb This is the Way the World Ends). But here, post Covid, the really scary aspect is that the imagined reality for mankind's potential demise is entirely feasible.
So, this is a wonderful mix of horror, science fiction, alternative history, but also a moral fable about personal development and atonement. I didn't get at all one review which said the survivor was not a likeable character. I thought she was strong, emotional and full of humanity. And as for the only other surviving character, Lucky the dog, well you will need a heart of stone not to love him. Do they all pull through? You will need to get to the very clever ending. I read the entire book in 4 days. I hope you love it as much as I did.