Clary (Lily Collins) has been living in Brooklyn since she could remember, living a simple and peaceful life with her single mother Jocelyn (Lena Headey). However, she suddenly saw some incredible and strange things, and her mother disappeared after a violent conflict. As she and her best friend Simon (Robert Sheehan) searched for her mother, Clary began to discover the dark secrets and more evil and dangerous forces hidden in the world of shadow hunters. For centuries, shadow hunters with half angel blood have been quietly protecting humans from the invasion of evil forces. The shadow world surrounded by demons, wizards, vampires, werewolves and other supernatural creatures welcomes Clary to join. She and the young shadow hunters Jace (Jamie Campbell Bower), Isabella (Jemima West) and Eric (Kevin Zegers) have found the ancient Holy Grail related to the future of Clary's mother, and work together to protect the Holy Grail from being taken away by bad guys. Young Clary discovered her unprecedented superpowers and courage, and proved with practical actions that she is a powerful new fighting force against dangerous enemies...