** spoiler alert ** 
 I would have given this three stars, but the last forty pages are so bad that when it came time to rate it I was still pissed off. 
 Overall, this book is a mess. Some sections are really good. There's definitely some good tension and a creepy air of mystery throughout the first two-thirds. Other sections really needed some more time with the editor; there were many spots where it wasn't clear who was speaking. 
 Finally, the characters I loved so much in the first book really pissed me off in this one. Decker is completely mentally abusive to Delaney throughout the entire thing, AND SHE LETS HIM. Even when she "calls him out", the next scene it's back to the old routine. He's a completely toxic asshole for a large part of the book, even when he's being "nice", and it feels like the author wasn't even aware. He slut-shames Delaney for her Halloween costume while they're broken up, and this leads directly to them getting back together (WTF). The entire book is Decker getting a pass on being a dick and running around playing detective and shaming people for not living up to his standards. It's awful. Several (all?) female characters are painted with some really ugly, tired stereotypes (slut, dumb slut, unworthy girlfriend, cute sweet girl-next-door who will forgive anything, etc). I guess one could argue that it's because this book is told from a high school senior boy's perspective, but that just adds to my argument that Decker is a fucking asshole, and it definitely makes the book less than it could have been. 
 As far as the actual mystery goes, there's one part that you'll probably have figured out pages and pages before the rest of the characters, one red herring that really jars with the rest of the story and ends up being what I felt was a loose end that never got tied up, and the rest you'll never be able to figure out ahead of time because characters are behaving so non-sensically that there's no way you would guess it was them, or understand why anyone does what they do. The storytelling and logic is so flimsy in spots that it's hard to believe an editor ever even looked at this. It's extremely frustrating. 
 Rating: 2.5/5, docked an extra .5 for that abysmal final act. Not a worthy sequel.