To save Jocelyn(Clary’s mom), Clary has to go to the city of Glass(Idris). Shadowhunters would be breaking the law by going in there without permission and breaking a law equals death. Simon is in prison and Jace doesn’t want her there, so that makes matters even worse. Clary learns more about her family’s past, and finds Sebastian. Valentine is powerful enough to destroy Shadowhunters forever, there is only one option. The question is that can Downworlders and Shawdowhunters work together, despite their differences to kill Valentine and Glass city? SPOILER ALERT: Jace isn’t Jonathan Christopher Morgnstern.