In a world where tall ships have led to expansive conquests, people are saying a masked man is leading a resistance against the imperial occupiers. Able Houser, a scholar struggling with a stalled career, is both skeptical of the stories yet hopeful that they could be hiding the trail of the insurgents his father was helping when he vanished twelve years ago. After turning up hints of a government cover-up, Able sails across the sea to investigate further and becomes entangled not only in the conflict between the imperial enforcers and the native people but also in a long-standing conspiracy.