I ate up the Old Man's War trilogy last year like it was a friggin' breakfast burrito during a hangover. It was my first exposure to John Scalzi, and it was delicious (especially #1). Zoe's Tale is a re-telling of the final book in the OMW trilogy, The Last Colony, from the perspective of the protagonist's daughter, who played a pivotal but largely unseen role in the story. Because I'd enjoyed the original trilogy so much, and because I'd been burned by re-tellings before*, I was a little wary of Zoe's Tale, despite my faith in Scalzi as a storyteller.
*Had a nasty reaction to Ender's Shadow a couple years back. I did end up enjoying the sequels to that story, but I still kind of hate what Orson Scott Card did to the events of Ender's Game by placing so much credit on Bean's "behind the scenes" actions. I liked the Bean backstory, but I thought the "new" events in Ender's Shadow took away some of the magic from the original story. I should stop now or this could will go on for a while.
It is possible to go into Zoe's Tale not having read any of Scalzi's other writing, but I wouldn't recommend it, not only because it would ruin the story if you ever decided to read Old Man's War, but because Zoe's Tale just isn't as good as the other three books. I don't know if I would feel the same way about it if I hadn't read the other three, but I obviously have no way of knowing at this point. The only way I can honestly review this book is in the context of its predecessors. My verdict is largely that it was a fun idea, but I'm not entirely sure it needed to have been written, at least, not as a whole novel. It was sort of fun seeing Scalzi put on the persona of a sixteen year old girl, and it was nice to see things through Zoe's eyes, but all the narrative tension was mostly non-existent for me, because hey, I'd already read the story before in another form. But that's always the danger of re-tellings: you have to find a way to make the story succeed even though the audience knows what's coming, and I'm not sure that Scalzi did that. At least, not for me.
Again, reading this book is a particularly subjective experience, so there could be people out there (and I'm sure there are) who completely disagree with me. This was a fast, fun read, but really there were only two scenes in the entire book that warranted this re-telling: the scene where Zoe saves everyone from the werewolf things (a scene I missed in The Last Colony) and the whole ending sequence, which I imagine was Scalzi's justification for this whole novel in the first place. And it was really awesome. I'm just not entirely convinced he needed to write a whole novel along with it. Of course, there's also the strong possibility that I'm talking out of my ass. This book did make me cry, after all, even though I totally knew what was coming. I give it 3.5 stars, because of the ending, and because I have a strong suspicion that I'm an asshole and need to make up for it a little bit.
ANYWAY, you guys should all read Old Man's War, because it's awesomesauce. Peace out.