With word getting out that Clary is a key part of Valentine's plan, the Downworlders are at odds on how to handle the issue. But when Iris activates her blood oath, Clary has more to worry about than hiding from Valentine and the Downworlders. Meanwhile, Isabelle and Raphael get closer as Alec tries to figure out what's going on with his sister.
18 year old Clary Fray, finds out on her birthday that she is not who she thinks she is, but rather comes from a long line of Shadowhunters - human-angel hybrids who hunt down demons.
When her mother Jocelyn is kidnapped, Clary is thrown into the world of demon hunting with mysterious Shadowhunter Jace and her best friend, Simon. Now living among faeries, warlocks, vampires and werewolves, Clary begins a journey of self-discovery as she learns more about her past and what her future may hold.