Jace, Clary, Sebastion! Isabelle, Simon, Jordan, Maia! Alec and Magnus!!! Intense, Intense, Intense!
Again I am not going to go too much into the plot as it just wouldn't make sense without reading the first books. SO JUST GO AND READ THEM!!!
Oh, and P.S. The final book came out yesterday. I started reading it last night! I don't want to give away spoilers, but hory clappers!!! INTENSE AND SO FREAKING GOOD!!
Recommended if: You want to live!