3.5? The plot was interesting, after the beginning . For me, this book was hard to start. I could've and tried to read this a long time ago but the beginning didn't really pull me in. So long story short, I chose to read this book instead of sit somewhere and be bored, and after the first hundred pages, the book got somewhat better. I tend to avoid books about time travel, because things generally become confusing. But this book explained it in a kind of understandable way. 
 As this book so cleverly pointed out, the thing with Emma was gross. Emma, who was with his freaking grandfather. I guess that when books point things out just like how it did with Emma, it's supposed to justify the fact and makes it okay for it happen in a book? Of all of the weird twists that come with time travel, I never expected something like this to happen.