From amazon.com:

Narashtovik has been saved—but Dante and Blays' friendship has been destroyed.

Blaming the Gaskan king for the loss of his love, Lira, Blays infiltrates the enemy nobility. There, he schemes to bankrupt Gask and drive its ruler from the throne. But Dante's been waiting for Blays' return. If he finds and exposes him, Blays will be executed as a spy.

As they squabble, strange lights shine in the east. Harbingers of a long-forgotten threat. If the signs go ignored, Narashtovik will be annihilated by an enemy it never knew it had.