I read this book about a year ago so I'm reviewing it from what i remember sorry for the vagueness
I think this should have been the last one in the series. I feel it tied everything together. The specials show a harder side of tally and the cruelty of society they live in. Tally has become a special. The surgery has made her scary and mean. She is used as weapon for the people in control. This book ties in the changes and hard ships from the rest and madeeveryone in the series who they become in this book. personally i wish she stayed with David i liked him the best but oh well lol.
I recommend this book from the series to close it up I feel like the extras (the book that follows is exactly that)