When the Silent Brothers are murdered and the second of the Mortal Instruments, the Sword of Souls, is stolen, the terrifying Inquisitor is dispatched from Idris to investigate. She clearly harbors a personal grudge against Jace, and she drives a wedge between him and his adoptive family. When Clary's romance with her best friend, Simon, starts to heat up, Jace feels abandoned. But has he, as the Inquisitor accuses, joined up with his father?
Then Simon is turned into a vampire and kidnapped by Valentine, who intends to sacrifice him as part of a bloody ritual that will make the Mortal Instruments his own forever. Jace knows he needs to save Simon's life, for Clary's sake. But what if he's too late? What if Valentine has already made the Mortal Instruments his own?