It's a really interesting book, a mundane girl who can suddenly see demons and shadow hunters. And there are some really interesting ideas, like the stele, and using runes to fight and all. But that was really underdeveloped, since I wasn't quite sure what a stele was at the end of the book. And the runes thing was fully explained either. The characters were okay, and Clary was likeable enough...but I didn't find them particularly interesting. There was something about them that fell a little flat for me. 
 The Jace and Clary are siblings storyline was a bit obvious, and his father turning out to be the evil Valentine was also a little obvious. It was also reminiscent of Star Wars. "Luke, I am your father." Sorry, I just had to go there. The big revelations weren't that surprising. 
 The writing was just okay. It was fast-paced, and the action starts right off the bat. There were times when I wished Clare had slowed down the pace and explained a few things a little more. They might be explained in the other books in the series, but if they weren't, I would not be surprised. 
 I did like the history of the Shadowhunters, and how they came to be. Clare clearly put some thought into it, and I liked the world she created. It's interesting, and there are all kinds of creatures and groups. It was hard to keep track of them, though, and who was good and bad. But still, the idea that there's a whole world that "regular" people, or mundanes as they're called in the book, don't know about. People that they can't see, and a country that they don't know exists. 
 I enjoyed the book, but I don't know if I want to finish the series. I have a lot of other books I'd like to read, so it's not high up on my priority list. 
 I give it a 3 out of 5.