At the party, Magnus informs Will and Tessa about some plans for a demonic clockwork army found in the library, but they are forced to join the other vampires in another room before they can discuss the matter further. The room is set up to host one of de Quincey's 'performances' but as the human is revealed to be Nate, Tessa blows her cover in an attempt to save her brother. Will summons the other Shadowhunters, who fight and kill the vampires.