City of Bones, the first book in Cassandra Clare's bestselling Mortal Instruments series, is an urban fantasy novel about 15-year-old Clary Fray. Clary's life is upended when she witnesses a murder at a New York City club, committed by tattooed teens with strange weapons. The body vanishes, and only Clary can see the murderers, who identify themselves as Shadowhunters, a secret group of demon-fighting warriors.