Humanity has been brought to the brink of extinction. Each night, the world is overrun by demons—bloodthirsty creatures of nightmare that have been hunting the surface for over 300 years. A scant few hamlets and half-starved city-states are all that remain of a once proud civilization, and it is only by hiding behind wards, ancient symbols with the power to repel the demons, that they survive. A handful of Messengers brave the night to keep the lines of communication open between the increasingly isolated populace.

Briar Damaj is a boy of six in the small village of Bogton. Half Krasian, the village children call him Mudboy for his dark skin. When tragedy strikes, Briar decides the town is better off without him, fleeing into the bog with nothing but his wits and a bit of herb lore to protect him.

After twenty years, Ragen Messenger has agreed to retire and pass on his route to his protégé, Arlen Bales. But for all that he's earned the rest, he has no idea what to do with the rest of his life. When he learns Briar, the son of an old friend, is missing, Ragen is willing to risk any danger to bring him safely home.