Sequel to TMI Gang In School. Clary's son-Jonathan-is now 12 and his younger sister-Tessa-who is now 11 are now ready to train. But Jace and Clary are having difficulties when they discover that Stephen Herondale-Jace's biological father-is really alive and never got killed but was held captive by Valentine. Jonathan-Clay's brother-changed his name to Sebastian because that's who he is really known as. Sebastian was the one who found Stephen locked up, bleeding and at dying point. Izzy and Simon still only have one child-Cecily. Alec and Magnus adopted a baby warlock and named him Malachi Raphael Lightwood-Bane.