Alec asks Magnus to hold his little brother Max's Rune Party at his loft, Magnus agrees. Simon confesses his love for Clary and they start dating. Isabelle is now getting her yin fen fix straight from the source by letting Raphael feed on her.
Max's party is in full swing when things take a turn for the worse, and guests begin seeing their fears and insecurities manifest. Magnus determines that they have all been be-spelled by a hostile warlock and undoes the curse. He then identifies the culprit as Iris Rouse, captures her and sends her to Idris.
However, Iris invokes the blood oath Clary swore her and instructs her to find the warlock child Madzie who has been kidnapped by Valentine. Jace and Clary tell their friends what they have learned of the Soul Sword and of Clary's runic abilities, which Magnus identifies marks her as angel-blooded, and thus able to activate the Soul Sword herself. Maryse tells Alec and Jace their father has been cheating on her.
- Talking Down the Suicidal: Clary attempts this with Alec when he is standing on the balcony ledge, but Iris' spell means he only hears her goading him.