Ten

I tried so hard to come up with a flaw that this book had. Ever since I saw the blurb I was SO excited to read this, and so, naturally, I half-expected it to be awful, or at least have some major problem that would ruin my excitement and enjoyment.
SO not the case.
I'll admit, this book does start slow. You have a handful of chapters of somewhat annoying exposition, with the main character, Meg, being a little whiny and a little annoying, and all the other characters being VERY annoying. You have the standard love triangle with a twist (the twist being one side of this love triangle is kind of insane). Then you have hints towards past events that aren't fully explained, which make the reader go "wait, did I just miss...no, okay, they're not going to tell us what that means yet."
Once you get past this beginning, however, the book begins to pick up. People start to die. (That isn't a spoiler, the blurb clearly states it.) And then, once you hit the halfway point or so of the book, it TAKES. OFF. My reaction on just about every page of the second half was "OHMYGOODNESS, really?" "THAT happened?!?!" "Are THEY the killer?" "No, it has to be THEM." "OMG NO HOW COULD IT BE....WAIT WHAT."
In addition to the fast pace and the legitimately fright inducing writing, this book had a real plot. And it was a FANTASTIC plot. And I was freaking out the whole time trying to figure it out. Maybe I'm just stupid, but I do watch/read a lot of murder mysteries, and I totally didn't figure this one out. The author sufficiently twisted my brain around and kept me from seeing what was right in front of me, and it's safe to say I didn't know exactly how this would turn out until the ending. Once I saw it laid out, it made perfect sense, and I was SO HAPPY. The entire book I was terrified the ending was going to be stupid, and it was anything but.
Another major plus to this book: It has a message. It's a somewhat hidden, underlying message about the potentially tragic effects of bullying, and the consequences of your actions, and the author never chooses to hit her readers over the head by reiterating it, but it's there nonetheless. And, besides being a great and poignant message, it also serves to make this book modern, relevant, and relatable to YA readers.
If you like murder mysteries or horror stories and you haven't read this yet, you really need to fix that. If you're trying to get into the genre with something creepy but not gut-wrenching, I definitely recommend this as well. Even if neither of these categories applies to you and you just want to read a really good book, I would still give this a try. In a nutshell: READ THIS BOOK. You won't regret it.