Tavi is ostensibly serving as a page but secretly training to become a spy. When the first lord falls to a sorcerous attack, Tavi and his closest friends and teachers must conceal the lord's condition lest the realm fall into civil war. In the Calderon Valley, a long--forgotten horror awakens and heads for the heart of Alera, while Tavi's closest relative, the newly appointed Steadholder Isana, faces at least two sets of assassins.

The savage Vord are on the march, and Gaius Octavian, first lord of Alera, must lead his legions to the Calderon Valley to stand against them--using all of his intelligence, ingenuity, and fury craft to save their world from eternal darkness.

"For a thousand years, the people of Alera have united against the agressive and threatening races that inhabit the world, using their unique bonds with the furies--elementals of earth, air, fire, water, wood, and metal. But in the remote Calderon Valley, the boy Tavi struggles with his lack of furycrafting. At fifteen, he has no wind fury to help him fly, no fire fury to light his lamps. Yet as the Alerans' most savage enemy--the Marat horde--returns...