Isabelle asks the vampires for venom, but they surround her to get blood. Raphael arrives in time to save her. Her body goes through withdrawals and Raphael tells her to stop. She begs and he gives her venom one last time.
Clary and Jace tells Luke about the purpose of the sword and their mysterious vision.
Max and Maryse return to the Institute. Max has passed his last trial and he will get his Rune Ceremony. Alec must throw the party for his brother.
Maryse isn't happy Alec is dating a warlock. Alec asks Magnus for help in throwing the party.
Valentine finds Iris in the park with one of her children. He has his minions surround the child and forces Iris to do anything for him.
Simon texts Clary to meet him so that they can talk. He admits his feelings to her and they kiss.
Alec confronts his mother about her hatred to Magnus and Jace. She claims her trying to kill Jace was because of orders.
Jace admits he knows that Magnus and Alec slept together. He wants to protect his brother. Magnus promises to not hurt Alec.
Maia is working the bar at Max's party. Her and Jace spot Clary and Simon walk in together. The two wish them luck, but Clary looks jealous seeing them be friendly. She follows them to the patio and spots them kissing.
Maryse gives Magnus a gift for helping to throw the party. Magnus reveals the theme is to celebrate Maryse and her husband. She gives him a snide remark.
Clary is upset over the kiss. Simon says Maia kissed him, but he has a connection with her since they're Downworlders. She's about to leave and Magnus stops her.
Isabelle goes back to Raphael to ask for more venom. Raphael declines and tells her to sweat it out. She cuts herself and lures him in with Shadowhunter blood. He bites her.
Magnus gives Max a gift. Max wants to see Magnus's warlock mark and he obliges. Once he does, Max flinches and when Jace tells him to say sorry, he says Jace isn't his brother because his mother said so. Maryse goes to see Jace and tries to kill him.
Raphael tells Isabelle about his past and how Magnus helped him as a new vampire.
Clary sees Simon and Maia flirting again, but Magnus stops her from making a scene. He turns to see Simon and Raj talking. Clary tries to leave and before she does, she condemns Alec for killing her mother.
Magnus revives Maryse and deduces that someone is playing a spell that is playing on their insecurities. Maryse never tried to kill Jace. The group hears noises and sees Alec on a ledge. Clary tries to calm him down but he walks off.
Magnus saves Alec just in time. He reverses the spell that was done against them and as he finishes, his spell book disappears. He places a barrier on the building to stop the intruder.
Iris, hiding in the form as a ginger cat, has stolen the book. Magnus reveals her identity and the two have a magical fight in the apartment. He subdues her. She reveals that Valentine wants his book of counter spells.
Magnus sends Iris to the Clave. However, before he does, Iris claims his blood deal with Clary and demands that Clary save her child from Valentine.
Clary tells the truth about the sun rune to her friends. Magnus reveals that her receiving the rune is because she has some connection to the angel. She has pure angel blood in her and she could be destined to wield the sword.
Simon and Clary work out their issues. The two still stay together.
Max completes his Rune Ceremony and gets his first rune.
Clary apologizes to Alec and says that she doesn't hold him accountable for Jocelyn's death. Maryse apologizes to Jace about what she's said. Maryse reveals that Robert (her husband) has been cheating on her.
Valentine is still holding the child hostage and is waiting for Clary to find them.