3.5 starsI went into this with high expectations, considering all the love I've been seeing all over Goodreads. This book seems well-poised to be The Next Big Thing. I can see it happening. But alas, though it was enjoyable enough, this book isn't my Next Big Thing, personally.The book follows Em and Finn as they race to go back in time to kill a bad guy before he invents time travel and uses it to make the world a really shitty place. The complications: The bad guy is their former best friend, and their past selves, who have no idea that he's going to turn out evil, are naturally going to do everything in their power to protect him. We also follow Marina (Em of the past) and past!Finn as they cope with tragedy and crushes and figuring out who to trust. A fast-paced time travel thriller, this book might appeal to fans of [b:Divergent|13335037|Divergent (Divergent, #1)|Veronica Roth|http://d202m5krfqbpi5.cloudfront.net/books/1328559506s/13335037.jpg|13155899] or [b:Unraveling|12157365|Unraveling (Unraveling, #1)|Elizabeth Norris|http://d202m5krfqbpi5.cloudfront.net/books/1337474732s/12157365.jpg|17128227].I actually almost DNFed this halfway through. I was bored. I felt like I'd read this story before. I think I only kept going because of all the glowing reviews I'd read. I figured there had to be something more than what was there in the beginning.I'm actually glad I continued. I really enjoyed the second half of the book, once the past and future versions of Marina, Finn, and James (best friend/bad guy/crush) started interacting. The pace picked up, there were more cards on the table, and shit got complicated.In the end, this book was solid but not amazing. I'll keep it in mind to recommend to the teens who want to read The Next Big Thing after Divergent--they'll probably enjoy it more than I did.Note: Thanks to NetGalley and Disney Hyperion for providing me with an advance copy of this title.