The War for the Mortal Instruments is over, and Clary Fray returns home to New York. A lot of new and exciting things await her: she learns to be a Shadowhunter, her mother marries her beloved, the Nephilim and the undead finally live in peace, and most importantly, Clary can now be with Jace. But nothing comes for free. Someone is killing the Shadowhunters hunters who were once members of Valentine's Circle, and plants corpses in the territory of the undead. The provocation threatens a new bloody war. Meanwhile, Jace, for no apparent reason, begins to move away from Clary. She is forced to unravel the mystery, not even suspecting that she will end up facing a terrible nightmare. Without knowing it, Clary has started a chain of events and as a result she risks losing everything that is dear to her. And Jace too. Love. Death. Betrayal. Revenge. The stakes in Cassandra Clare's new novel are higher than ever.