I think I'm being stingy on my stars.... 
 Love the premise, but I'll sign up for a dystopian YA with a supernatural twist almost any day, so I'm an unreliable source. 
 The plot moved quickly, which I appreciated, but it's the characters that make you care. I loved the characters. The author did an excellent job of walking through each character's struggles and burdens and making you care immensely for even ancillary characters. 
 I will say that as fast as the plot moved, I felt there were some redundancies in the dialogue or train of thought, particularly for Ruby. That, along with the glaring holes in the plot, lessened the value of the read for me. I needed more backstory and explanations on different entities in the book. I will continue on with the series, eventually, but it's not something I'm dying to pick up tomorrow. Super fast read, though!