There was a masterpiece buried in this book somewhere. I hate rating these kinds of books, because I'm torn between "look how much better this could have been" and "eh, this was pretty good already." In the end this ended up being just another YA dystopia, hitting basically the same beats as Sanderson's Skyward but without the redeeming qualities of M-bot or

actually dealing with the world-ending threat

, which was by far my biggest problem with the book. On the plus side, this did help me realize what makes a book feel YA to me, which is basically a young, naïve, brainwashed protagonist in a cult-like environment, i.e. where there is a (likely mysterious) Government ruling their entire world, which is either the only world we know about as readers or the only "safe" place in a wider world that is only talked about in hushed whispers. See The Giver, Hunger Games, Divergent, etc.

As for my issues with this book...

There's an extremely obvious solution to the problems of both timelines we experience: send Kyr back to the orbital defense platform again, where she kills Jole and jumps the planet-buster away. As soon as that's accomplished, Wisdom destroys itself. It seems extremely likely that the fascist Terran empire falls apart without Jole and the broken Wisdom. What's that? You're afraid Earth will just develop its own Wisdom? a) it took millennia for the Wisdom to develop into a godlike reality-manipulator, and a lot can change in millennia; b) sorry, you don't get to genocide a planet because you're afraid they're going to become fascist overlords, who as far as I could tell weren't actually committing any genocide themselves until Jole was driven over the edge. (Not that genocide-less fascism is ok, but it's better than fascism-less genocide, at least in my and many authors' opinions, being that there are whole genres about this out there.) Still don't like that solution? Time is literally not a problem. Spend a few decades Groundhog Day-ing scenarios where you push different levers just right until you find a future without immediate fascism or genocide, then Wisdom destroys itself. (It's impossible to solve all the problems of the past and future, but both of those are immediate and relatively straightforward.) You want to highlight the value of cross-cultural understanding and cooperation? Yiso and Kyr work together to do this, crafting a future where there's a chance at happiness for everyone.

Which brings me to the next part of my rant... Val's timeline was so much more interesting than Kyr's, and in the end it felt like Jole's genocide was just to have an excuse to put Kyr back in the box of Gaea, where, great, she saves everyone in the cult (totally unrealistic, by the way), but hardly thinks about the wider world at all, beyond wanting to save Chrysothemis from Jole (this part, possibly realistic—hard to break out of a small perspective when it's all you've ever known). I've seen the suggestion to alternate Val and Kyr perspectives instead of having them linear, which already would have made the cult timeline much more interesting.

Overall, disappointing for a Hugo nominee, not as good as Greenhollow (but also very different), fine for what it was.