I liked this book and it definitely kept my interest. I can't wait to read the rest of this series and hope it gets even better. I like both characters enough, although I probably like Day even more than June. 
 My only issues were with Day and June's ability to figure out everything in like five seconds, yet the easiest conspiracies were above their heads when I was able to figure out all the predictable twists. I would have liked for June especially to have to take time to figure things out then maybe certain clues wouldn't have slipped past her. 
 Nonetheless I really enjoyed this book. I'd definitely recommend it to young readers. Marie Lu is excellent.