A net of shadows begins to tighten around the Shadowhunters of the London Institute. Mortmain plans to use his Infernal Devices, an army of pitiless automatons, to destroy the Shadowhunters. He needs only one last item to complete his plan: he needs Tessa Gray.
Danger intensifies for the Shadowhunters as the New York Times bestselling Infernal Devices trilogy comes to a close. If the only way to save the world was to destroy what you loved most, would you do it? The clock is ticking. Everyone must choose. Passion. Power. Secrets. Enchantment. Danger closes in around the Shadowhunters in the final installment of the bestselling Infernal Devices trilogy.