I have mixed feelings about this book. I think I would have enjoyed it more if I haven't read The Mortal Instruments series before. The plot and the characters felt too familiar and predictable for me to be truly engaged in the story. 
 Will is basically a carbon copy of Jace. I have a little problem with that, because I don't want Cassie Clare to announce in City of Heavenly Fire that Jace is Will reincarnated. 
 Tessa is a more reasonable and level-headed version of Clary. 
 Jem is an odd mix of Alec and Simon. 
 Nate is (view spoiler)[Sebastian (hide spoiler)] 
 Magnus is... well, Magnus, but somehow he was more funny and interesting in TMI. I definitely like him more with Alec than with Camille. 
 As for Axel Mortmain (view spoiler)[one could see from a mile away that something was wrong about this guy. It is easy enough to guess that someone named like that would end up either dead or a villain. And again, I liked Valentine as a villain better. (hide spoiler)] 
 Jessamine. Hmm, I saw many people compare her to Isabelle, and maybe I thought so too in the very beginning, but as I read on, it became clear that the two are nothing alike. Jessamine is just a rude and hateful prissy missy, I don't like her at all. Maybe the next books are going to reveal that she has a heart of gold hidden somewhere deep inside, but I honestly doubt that. 
 So because of all those similarities this book didn't keep me on the edge of my seat. But despite everything, I still wanted to know what was going to happen next, enough to pick the next book Clockwork Prince right away. Yeah, I'm a sucker for Cassie Clare's Shadowhunter world.