Samuel and Mary are thriving as privateers on the Winter Seas, forging a better way to live under the sails of Hart. Thrust into a mission of intrigue and infiltration, they seek to break into the most secure prison on the Mereish Coast. But as they sail deep into enemy territory, they find themselves hunted by a cunning and mysterious new foe, an enemy who seems to know their every secret, and who will kill to keep their own.