In this breathtaking finale to The Mortal Instruments series, Clary and her friends fight their greatest opponent yet: Clary's own brother, Sebastian Morgenstern. Possessing the Infernal Cup, Sebastian now has the power to transform Shadowhunters into creatures out of nightmare, tearing apart families and allies as he swells the ranks of his Endarkened army. The embattled Shadowhunters withdraw to their stronghold of Idris, but not even its demon towers can keep Sebastian at bay. But with the Shadowhunters trapped in Idris, who will guard the world against demons? Then an act of shocking betrayal sends Clary, Jace, Isabelle, Simon, and Alec fleeing from Idris into the horrific demon realms, where no Shadowhunter has set before, and from which no human being has ever returned! Your teens will be breathless at the non-stop action, adventure, romance, and magic in this final volume of her best-selling Mortal Instruments series, carried along spellbound by the epic battle for the fate of the world. Ages 14-up. 725pp.