Paul Heitsch did a great job narrating. A real professional.
The idea a space crew returns after a centuries long mission and finds the home world destroyed or knocked back to the stone age isn’t that original. Then the crew killing each other over the possibility of not being rescued, again nothing unique.
I found the story rather predictable. The protagonists weren’t well fleshed out and as a result I felt no sense of fear for them not did I care what happened to them; even though I felt I knew all along.
Dalzelle seems to think evolution happens very quickly. He has humans on Mars and on Earth as being physically evolved over just 800 years. The study of mummies shows us little if anything has changed in humans over the past 5000 years. So I know that tickles the ears of many modern readers, but I don’t expect it.
I do think a major breakdown in society is possible, even somewhat likely, following a major holocaust as portrayed in the book. Dalzelle creates a few unanswered questions that his characters even ask, but we get no answers. A sequel could well be written with a conspiratorial plot. Perhaps it has been and I don’t know about it.
In conclusion, I’d say this book was an ok time-filler, but nothing special.