I'll not resummarize the plot here, I will however point out a few things that bugged me. 
 1. Cal comes off as a spoiled teenage brat rather than a boy who has been through a lot and lived to tell the tale. The interactions with his brother are snarky, which is fine, but his interactions with others... that's where his immaturity shines, it grates on the nerves after a while. 
 2. Robin Goodfellow - at the end of the book we learn something about Robin that I don't think fits within his already established character. It felt very off to me, and not because of its nature. I do feel like this should have been made apparent at the beginning if it was important enough to mention at the end. It's not important to the plot but, his character's motivation. It's just one of those things that I was like ... well that was useless and now I'm feeling like I don't even know who this guy was supposed to be! 
 3. A lot of the inner voice of Cal, whose POV you follow, seems OBVIOUSLY streched to proove he's a badass, and a MAN. 
 Overall, despite these things, I did find the novel enjoyable, though I figured the ending before it was the ending as the only logical conclusion. 
 I do wish the novel had followed Nik as the POV rather than Cal. He was more mature and I just think it would have been a smoother novel from his prospective. 
 All in all, a good read with an interesting world.