Pretty much a triumphant conclusion to the series as the empire sets out to invade the Peninsula one final time and the fragile alliance of the three kingdoms struggle to make their people work together to drive them off. There are setbacks and betrayals and trials and losses, and some of the worst perils turn out not to be on the battlefield, but more or less in the soul of the Thief who is also High King. And as usual we see it all through the eyes of an unlikely narrator who has hidden strengths only the Thief is perceptive enough to spot first. 

Although the novel itself lacks the usual mythical tale the rest of the books have always included, there is a short stry at the end that elegantly braids myth and reality - misleading terms because the gods in this world are real, and the it's a fantasy land not a real one, but you know what I mean.