City of bones, by Cassandra Clare

15 year old Clary and her friend Simon are in a New York club when Clary witnesses a murder committed by three teens covered with strange tatoos and using bizarre weapons. But she is the only one who can see the 3 murderers, and the body disappears. Clary soom finds herself deeply involved in a clan of Shadowhunters - warriors dedicated to hunting and killing demons who stalk the earth. And the Shadowhunters are interested in finding out why Clary has the sight that allows her to see them and the demons. Clary soon finds that her life up to now has been a falsehood, and almost everyone she knows is not who she thought they were. Her friend Simon is her only constant friend, tho she is soon drawn to a handsome Shadowhunter named Jacy, who is equally drawn to her. There are plots and counterplots, twists and turns on every page. Fantasy readers won't want to miss this one and it's sequels.