I really enjoyed this book, but I couldn't help comparing it to the Harry Potter series. The villains Valentine and Voldemort both formed a band of loyal followers years ago (the Circle and the Death Eaters). They both disappeared either soon after or right before the main character was born. Both Valentine and Voldemort want to get rid of those who aren't pure bloods, either half demons or half muggles. Also there is a scene at the end where Jace has a piece of the portal mirror and he is looking in it, angling it to see Idris, where Harry keeps a piece of a mirror which he can see Dumbledore's brother in. Harry had no idea he was a wizard until he was 10, and Clary had no idea she had Shadowhunter blood until she was 15. There were a few too many similarities for my taste. This book was not nearly as original as I thought it was when I started reading it.
I also really hated Jace, I think he is way too egotistical and arrogant. I did not find myself attracted to his character in the slightest. I just found myself rolling my eyes and wanting him to get over himself.
I think that this story was really well written, filled with lots of interesting supernatural creatures. There were a lot of twists in this book that I was really not expecting, which I always love in a book. I think out of everyone Isabelle is my favorite character and I hope she plays a bigger role in the next book. Regardless of the many similarities to Harry Potter and my hatred for Jace I still loved this book and I will be reading the rest of the series.