To help get answers to what Valentine may be planning, Isabelle and Clary are sent on a mission to visit the Iron Sisters. Once there, more truths may be revealed than Izzy and Clary planned. On a mission of their own, Simon and Maia are determined to find Luke who is still missing after the demon attack at the Institute. Meanwhile, Magnus and Alec finally go on their first date.
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.