3.5 
 There were a lot of things I liked about this book, but a few flaws as well. Like, I really enjoyed how EVERYONE knew about time travel, it was a part of their lives, but I feel like the rules and exceptions should've been explained more because there were some parts that definitely left me really confused. I also feel like poor Mike was wiped out of existence for like, half the plot. I mean, yeah I know his twin played a bigger role, but he was a character too and shouldn't have been tossed aside so often like he was. 
 So, yes, this book was decent...but could've definitely used some more fleshening-out.