The Iron Sisters are testing our seraph blades. The leader sounds the alarm after the City of Bones was attacked.
Clary and Jace try to determine the rune she drew on her hand. He warns her not to tell anyone.
Simon calls Raphael for help after his mom saw him feed. He offers to help, but there will be consequences.
Clary is forgiven for stabbing Isabelle. Isabelle explains that the Iron Sisters are a group of powerful Shadowhunters who create their weapons.
Isabelle gets a refill of medicine from Victor Aldertree. She requests Clary to join the visit to the Iron Sisters, but he will only grant the order if Isabelle reports Clary's behavior during the visit. The Clave fears Clary was experimented on by Valentine when she was in the womb.
Simon visits the restaurant in search of Luke; unfortunately, he's not there. Luke is in the woods and transforms into a wolf.
Magnus invites Alec over because he's worried about him. He convinces him to do something for himself.
Maia and Simon team up to find Luke. Simon figures Luke is near the campgrounds where he used to camp.
Clary and Isabelle visit the Iron Sisters for answers, but they're ambushed and surrounded by the fighters. Luke's sister is one of the Iron Sisters. They force Clary and Isabelle to perform a cleansing ritual to see if they are truly good or evil.
Alec and Magnus head to a bar for their first date. They play pool. but Magnus is clearly winning.
Maia and Simon bond over the fact they're Downworlders. She reveals a story about how she transformed and woke up naked at school. He reveals his story about feeding on a rat.
Alec lets slip that he's never been in a relationship before, not including his arranged marriage to Lydia.
Clary performs the cleansing ritual. She is cleared of any impurities, but the water starts shifting once Isabelle enters. The Iron Sisters won't let her through. The medicine she has been taking is actually vampire venom. The venom doesn't actually heal her.
A flashback reveals how Maia and Luke met after one of her changes/attacks. Luke promised to protect and be there for Maia.
Alec and Magnus have a serious chat about their past relationships. Magnus had 17,000 relationships in his life. The date is becoming awkward.
Aldertree makes Jace shine the seraph blades in the Institute. Jace declines, but Aldertree blackmails him to leave by threatening to show the video from the City of Bones interrogation.
Luke transforms into the wolf and is about to attack unsuspecting campers, but Simon stops him.
The Iron Sisters give Clary a warning of what the Mortal Sword can do. If wielded by an angelic being and struck by lightning, it could cause devastation. Clary shows the leader the mysterious rune that emits sunlight.
Alec kisses Magnus after initially feeling they were too different. Before they get closer, Jace walks in and ruins the mood.
Isabelle accuses Aldertree of not telling the truth of the demon medicine. He's about to throw it away, but she changes her mind. He asks her to tell him if there's anything else about Clary, which she says no.
Sister Cleophas stabs one of the Iron Sisters and make a break for it from the compound.