I always feel like it's a good sign when the sequel is better than the author's first book. This tale is really improving as it goes along. The overall series arc is about the cyborg(show spoiler)
Cinder and her love for the Earthen prince Kai and how they have to defeat the very powerful Queen Levana. But the 4 books in the series have different heroines, each representing a fairy tale character. This time it was Scarlet (Red Riding Hood) and her hero, Wolf, who introduces us to the awful might and ferocity of Queen Levana's army. Gradually all these people band together and become friends and I'm sure will all play a big part in the evil Queen's defeat in the final book, Winter.
I really liked Scarlet's fiery nature at first but she did tend to rush into danger without a lot of thought. Wolf was perfect for her and it is absolutely imperative that you read his short story The Queen's Army before this one. You won't regret it. The author only uses the barest bones of each fairy tale and the story woven around it is full of action, adventure and magic. I LOVE Captain Thorn! And I'm very excited that he will be the love interest of the next heroine,Cress.