Oh. My. This book was so good. I don’t know that I’ve ever come across a time traveling story I like as much, and I love time travel as a trope. Holy crap. This book seemed to have about six endings - around the halfway mark was a huge climax that had me wondering how it could go on, and then it did, and it was so much action and suspense and really exciting writing all the way through the end.
Lately I’ve been frustrated with the inclusion of random romance/relationship plots, but this book nails the reason you’d include one - it makes every “ending” feel so much heavier and more important and more terrifying.