I'm pretty invested in this series as I am with anything Oz related. 
 The main problem I had was that it had been so long since Wicked Will Rise came out that I forgot most of the characters and finer plot details. It would have been nice if the author had some more refresher's in the book. ...You know, where the narrator quickly recaps things from previous stories that relate to the current situation. I don't really think there were many here. Would have been helped a lot. 
 Also, I really thought this series was supposed to be a trilogy but obviously it isn't considering the ending. With a cliffhanger that big, there must be another book coming. This really felt more like a filler book to set up the finale. I don't exactly know how to put it into words but I just don't feel really fulfilled after reading this like I was with Dorothy Must Die and Wicked Will Rise. 
 Hopefully it will all be worth it for the finale. Which I hope comes out sooner rather than later so I don't forget this book entirely.