City Of Heavenly Fire

The Mortal Instruments Book 6. 

Darkness has descended on the Shadowhunter world. Chaos and destruction overwhelm the Nephilim as Clary, Jace, Simon, and their friends band together to fight the greatest evil they have ever faced: Clary's own brother.

Nothing in this world can defeat Sebastian but if they journey to the realm of demons, they just might have a chance. Read all the sensational books in The Shadowhunter Chronicles: The Mortal Instruments, The Infernal Devices, Tales from the Shadowhunter Academy, The Bane Chronicles and The Shadowhunter's Codex.