Wow. Take everything you knew about this crazy, fascinating world that Andrea Cremer has created and turn it on its head. Add more new characters, all who have great stories, amazing depth and such great interactions with each other. Add everything awesome about Shay and Calla and muliple it by five -- because both are really getting better understanding themselves and their roles in this book. Continue with the heart-wrenching Team Ren/Team Shay debate. And don't forget Andrea's style of writing, which makes it nearly impossible to put a book down, what with the flow and the plot twists. Finally, add the !!!!! cliffhanger. 
 And you get Wolfsbane. 
 Another 5* book!