I will start by saying that I have been very highly anticipating the release of this book. I Absolutely loved Clockwork Angel (the first book in the Infernal Devices series) and was left needing to know what happens next. This book was just so amazing. It was full of unexpected plot twists, and heart-breaking emotions. I did not want to could not put this book down. This book brings us back into the wonderful Shadowhunter world set in London, and as with the first book in the Infernal Devices series, I was completely lost in it and didn't want to come back out.This book really gets into the story that was developing in Clockwork Angel, and we really get to know the characters more. I loved getting to know Henry and Charlotte better, and seeing more of who Sophie truly is underneath. As always I loved reading about Jem, Will, and Tessa. Jem is really a lot more present in this book, and we really get to know Will. And for all of you Magnus fans, (I know there's millions of you out there) we get more Magnus in this one too. We also get introduced to some new characters. I really liked Woolsey Scott. The character interactions, as always are written so well, that you really can feel all of their emotions. I love reading from the different character perspectives because it really gives you the depth of them and you can really get into their head more, as well as all the different parts of the story you would otherwise miss. Of course we all know that there is confusion with how Tessa feels about Will and Jem. I can't really say much without being spoilery. I will just say that Cassie is so amazing in how she has written the whole thing. I have never felt so broken apart. I love both Jem and Will. This is truly a love triangle that absolutely ripped my heart into a million pieces, and I am still trying to pick them up and put them back together. It's really, really emotional to read. I will say I needed some tissues. I can only imagine that the next and final book is going to break my heart more, but hopefully restore it all to one piece by the end. I am very curious to see how it all ends up, but also nervous at the same time. I don't know if it is possible to not be broken at any outcome really.This is one of my favorite books I have read. Cassie just gets better and better with each book. She knows just what to do to pull you in, keep you completely engaged, and leave you needing more. Clockwork Prince is a whole range of emotions. I laughed, cried, got angry, frustrated, swooned, even got embarrassed with the characters. I felt like I left parts of my heart behind on some pages, that I don't know if I can ever get back. I will be nursing the ache in my chest until the final book, Clockwork Princess comes out. Do yourself a favor and read this book. (read Clockwork Angel first) If I could give this book a million stars I would. I love it!