Ashes: Or A twist on zombies that almost works

There are a lot of things I really liked about this book. The overall craft of character and setting is quite good. There are scenes toward the beginning of this book that will stick with me for years. Truly vivid stuff, and damn creepy too. And the characters are round and engaging. The mix of wilderness survival and zombie tropes makes for a fast fun read. All of this is good stuff. Unfortunately this book had a couple elements I just couldn't get past.
The first thing, and by far the most damning, is the science behind the events that shape this apocalyptic setting. And here is where I'm actually going to break my usual spoiler free review tendencies, because I can't talk about this book without doing so. Ready? Okay.
[spoiler]
Apparently the reason everyone between the ages of puberty and old age drops dead, and teenagers turn into feral cannibals, is a massive EMP burst. When this idea is first posited I was alright with it because it was a random theory pulled out of the air. But when it is later revealed that, yes, it was an EMP I was deeply annoyed. No. Just no. This isn't how EMPs work. Even taking the weirdness with people and animals out of the equation, the way this effects electronics in the book isn't even accurate. It's Hollywood bad, and fifteen minutes of research would have done this book a world of good. This bad science made it hard for me to proceed through the story, because it broke my suspension of disbelief so severely. The author could have told the same story, in the same way, and simply made the cause a mystery, and I would have been onboard. Alas.
[/spoiler]
Okay. Moving on.
The second strike against this book is the slow down in the second half of the book. The main character ends up mired down in a single setting, and the tone of the story shifts from adventure yarn to slow claustrophobic setting piece. And when the story ended on a cliff hanger I found myself groaning. I was curious enough to try the second book, but that's another review. ;)
Overall I'd say this book was so close to being great, but it ends up falling short due to pacing and lack of research. I can't help but feel that an amazing and honest editor would have really helped this book succeed.