There was an awful lot of filler in this book. I don't know whether Mead had a word quota or something, but I'm pretty sure that had this book been pruned, it would have been only 200 pages but it would have been an excellent read. There was too much lead up to the important parts. 
 The characters are incredibly dense at times, ignoring clues or little bits of information about Rose's strange powers that are right under their noses only to get the light going off in their heads much later. Surely at least one of them would have thought of these things before they got that far. Rose keeps too much to herself, too many secrets, but expects others to spill all of theirs to her - this really frustrates me about her. She's not a character that I can ever really see myself liking. 
 As I said, I didn't like the first part of the book very much at all, but the last part - all the action - was excellent. I even found myself rushing to read those bits. It was a rollercoaster of emotions - it was the series at its strongest. The ending certainly opens up a lot of possibilities for the next book. 
 As in the first two books, the style is very colloquial, but this is understandable considering the narrator. Again, I didn't feel that it had been edited as well as it should have been. Read comes up with some very convoluted sentences and it plays havoc with her syntax. She should opt for shorter ones where she isn't liable to end up with her prepositions all over the place. 
 The first half of the book was, frankly, boring. It was all filler. The second half of the book was the best the series has been so far (after having finished the series, it was the best part of the series). In the second half, Read was shining - she went through love, fear, heartbreak and determination. I was really feeling Rose's joys and pains as I hadn't before. But the mediocre first half lets it down. 2 star first half, 4 star ending - I'll meet in the middle. 3 stars.