City of Heavenly Fire is the dazzling and long-awaited conclusion to the acclaimed Mortal Instruments series. As the narrative unfolds, Clary and her friends are pitted against the greatest evil they have ever faced: Clary's own brother, Sebastian Morgenstern.

Sebastian is on a ruthless quest, systematically turning Shadowhunter against Shadowhunter. Wielding the Infernal Cup, he transforms them into creatures straight from a nightmare, shattering families and lovers as the numbers of his Endarkened army grow. The besieged Shadowhunters retreat to Idris, but even the legendary demon towers of Alicante are no match for Sebastian's onslaught.

With the Nephilim trapped in Idris, the question arises: who will protect the world from demons? As a staggering betrayal comes to light, Clary, Jace, Isabelle, Simon, and Alec are forced to escape—even if it means venturing deep into the demon realms, a place where no Shadowhunter has dared to go and from which no human has ever returned.

In this thrilling final installment, sacrifices will be made, lives will be lost, and the fate of the world will hang in the balance.