It may be that I'm too distracted by my own writing, but for all this book's strengths, despite the fact that I read it from start to finish, it just didn't grab me.
Fifteen-year-old Clary Fray is your typical high school girl...which naturally means she isn't. One evening, while at The Pandemonium club in New York with her best guy pal, Simon, she sees a beautiful blue-haired boy who is apparently about to get jumped by two other boys. When she tries to rescue him, she learns that pretty boy is actually a demon, and his two assailants are Shadowhunters, part of a force of humans dedicated to keeping earth free of demons and other baddies. Jace, one of the Shadowhunters and his companions is surprised that Cary, a mundane, can see him and his pals.
Soon after, Clary's mother is kidnapped. Clary, returning to her home in the aftermath of the kidnapping, is attacked by a scorpion-demon thing. (Clary's mother, btw, being one of those insufferable Harry Potter-esque adults. As in, even though really bad sh*t is destined to come after her and her daughter, she refuses to tell her child the truth. Fortunately, worst-mom-ever spends most of the book off screen and unconscious.) One thing leads to another, and Clary is now keeping company with Jace and the rest of the Shadowhunters.
I wouldn't call it a spoiler to say that Clary isn't an ordinary human. File that assumption under, "Well, duh." Therein lies much of the story's weakness. It's just so predictable and painfully obvious. Once Clary (and by default, this reader) gets fed a bit of exposition regarding the Shadowhunters and the world of The Mortal Instruments, it's screamingly obvious that a certain big bad is her father; that she's totally not a mundane. The former secret is drawn out forever, even though a blind man can see it coming from space.
But...the novel's world is kind of fun, and the story moves along at a decent pace. Jace, the "hero" of the story is sometimes funny, although his humor often feels a bit forced. Simon, Clary's best friend, is likable, although he gets short shift in the story, and is often delegated to sad comic relief.
Clary, the main POV character, though not a completely hapless heroine, is largely dragged along by the story's events. She's also [another of] the narrative's weaknesses; she pleasant but dull, and consequently, the story's voice is a bit flat.
The book ends with threads undone, which, I admit does make me at least consider reading the next in the series. But so far, I'm not in love with these characters.
(Edited to change Shadow Warriors to Shadowhunters, because I wrote this review under the influence of sleepy.)