Not 5 stars, 5 hearts! I give this series all the hearts in the world. 
 WARNING: I don't know if the following paragraphs are spoilers, but if you are a bit touchy I recommend not to continue reading. 
 Grim and Blackthorn's relationship grows in this book, a more mature relationship than the ones presented before. Not in the physical sense (although we do have A scene), but in the foundations of their love. In their depth. THIS, my friends, is the love we all crave for when we dream. 
 I want a love just like that... true, faithful, devoted and honest... Of course without requiring torture and rape to get there :P 
 In contrast, the second story line that accompanies Grim and Blackthorn, doesn't have the usual romance or love. It is a mystery between a father and his daughter. Thus, the balance is kept. 
 Grim has changed. He has a lot more confidence in himself and Blackthorn's heart has melted somewhat. I admire how swiftly their secrets and past were revealed, and how their characterization grew with every chapter. I would have loved a chapter with his POV at the ending... or an epilogue to take a look into their future seen through his eyes. 
 Grim and Blackthorn are the most well thought characters I have read this year, hand in hand with Robin Hobb's Fool and Joe Abercombie's Yarvi. 
 All hail the character masters!