15-year-old Clary Fray, goes to New York City’s Pandemonium Club with her best friend, Simon Lewis.
When she observes a group of strange yet attractive teenagers sneakily enter a storeroom, she hardly expected to witness a murder. However, no one else seemed to notice anything out of the ordinary - and when the body disappeared into thin air, it was near impossible for her to report a murder which left no traces behind.
Later, Clary is at a poetry reading where she sees one of the teens she saw at Pandemonium, named Jace. He tells Clary in confidence about demon-hunters, also called shadowhunters or Nephilim, and explains that the murder she witnessed was one of them. Jace also claims that Clary is not a regular, mortal human, because no mundane form can see beings like him. Meanwhile, Clary answers her mother’s frantic call, which turns out to be a warning for her not to come home, and the call ends abruptly. Suddenly, Clary is thrown into Jace’s supernatural world - her mother has disappeared, and she herself is attacked by a demon.