Based on the best-selling book series, a seemingly ordinary teenager, Clary Fray (Lily Collins), discovers she is the descendant of a line of Shadowhunters, a secret cadre of young half-angel warriors locked in an ancient battle to protect our world from demons. After the disappearance of her mother (Lena Headey), Clary must join forces with a group of Shadowhunters who introduce her to a dangerous alternate New York called Downworld filled with demons, warlocks, vampires, werewolves and other deadly creatures.