I really, really like the way Lauren Oliver writes, and her worldbuilding is honestly fantastic. In this book, though, it sort of overtook the story. I guess that's because the story was supposed to lead up to the reveal, which I didn't actually see coming but it sort of just...confused me. Like, I get it. I get what happened. But it was just weird. It didn't click with me as an "oh, that's why that happened!" It was just..."oh." 
 Also, Oliver really has a formula for her teen relationships. It still strikes a cord the third time I've read it, but far less so. And floppy boy hair isn't really a thing anymore. That stopped in like 2011. 
 I still liked it. So I'll give it a 3.5 stars. But like many people, the ending was a bit of a letdown.