There were a lot of changes going on in this book. Alec's insecurities and his quest to live forever beside Magnus had some very disturbing results. We get a glimpse into the way he thinks.
Simon is forever growing as a person. Even when he's losing or gaining powers, his heart is always in the right place. He starting to come into his own.
We get to see Isabelle's vulnerable side which is still rough around the edges, but at least she tried. Isabelle and her brother don't seem as close as they were previously portrayed.
Clary is determined to get Jace, the real Jace, back from the control of her brother, Sebastian. Sometimes it can be a little too much, but I suppose that's a teenage thing.
I don't know if it's just me or not, but I'd really like to get the whole idea of a brother liking a sister out of my head, but these books won't allow it.
I enjoyed this book even as I wished there was more fighting and less interaction with Sebastian.