This is the beginning of a very good young adult series. It features a good romance and good characters.
I love the character of Jace. I'm a total sucker for the dashing bad boy. The world that the story is set in is pretty awesome. The whole idea of Shadowhunters and fantastic creatures and places blending in with our world is perhaps my favorite part of the book/series.
Least Favorite Bits:
My only real issue with the book is the (and here is the spoilery bit) icky brother/sister ending. All I could think about was Luke and Leia in Star Wars. Having read the next two books and knowing that I had to deal with the ickiness for two more books doesn't make it any easier to swallow. Surely there was another way to keep the two romantic leads apart. Just...ick.