First Lord's Fury (Codex Alera 6) by Jim Butcher
For Gaius Octavian, life has been one long battle. Now, the end of all he fought for is close at hand. The brutal, dreaded Vord are on the march against Alera. And perhaps for the final time, Gaius Octavian and his legions must stand against the enemies of his people. And it will take all his intelligence, ingenuity, and furycraft to save their world from eternal darkness.