Tavi of Calderon, now recognized as Princeps Gaius Octavian and heir to the crown, has achieved a fragile alliance with Alera's oldest foes, the savage Canim. But when Tavi and his legions guide the Canim to their lands, his worst fears are realized. The dreaded Vord--the enemy of Aleran and Canim alike--have laid waste to the Canim homeland. And the Alerans find themselves trapped alongside their former enemies.

Meanwhile, war-torn Alera rebuilds while politicians and nobles vie for power. But from the south comes the news: the Vord have come to Alera. For a thousand years, Alera and her furies have withstood every enemy, and survived every foe. But the thousand years are over...