One young woman realizes how dark the city can really be when she learns the truth about her past.

With the knowledge that Valentine is alive and on the hunt for The Mortal Cup, the Institute is on high alert. Not wasting any time, Jace jumps into action and figures Clary’s memories are the key to finding Jocelyn and The Mortal Cup. Unfortunately, Clary’s memories were wiped leaving her without any recollection of this other life that could help her and the team. With only one other option remaining, Jace, Isabelle and a very reluctant Alec take Clary to the City of Bones to face the powerful Silent Brothers.

Meanwhile, Luke continues his search for Clary, and Simon tries to come to terms with his best friend’s new life.

The hunt is on for Jace Wayland, and Alec and Isabelle hope to reach him before the rest of the Shadowhunters do. With orders from the Clave of “shoot to kill,” the Lightwood siblings must act fast. Also on his own search, Simon turns to Magnus for help when he finds himself at odds with both Raphael and Aldertree. Meanwhile, Clary struggles to find where she belongs since she doesn’t seem to fit into the Shadowhunter world, yet can’t go back to her mundane life.

Clary continues to struggle with the new Shadowhunter order as Jace is being held in The City of Bones with an unknown fate, and all suspicion in the Shadowhunter world continues to rest on Valentine’s daughter. When duty calls, Clary gets a little reprieve from the family drama as she helps Alec and Isabelle hunt down a powerful demon. But what starts out as a routine mission quickly puts the Institute on high alert, and what happens next will change everything for the Shadowhunters and their Downworlder friends. Meanwhile, Jocelyn has a proposition for Clary as Raphael and Simon ramp up their hunt for Camille.

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.

The New York Institute is under attack as Valentine’s plan for The Soul Sword is getting dangerously close to coming to fruition. The Shadowhunters must act fast to save their loved ones and the rest of the Downworld. Meanwhile, some of the Downworlders have their own plan to stop Valentine and their target is Clary.