A desperate orphan turned pirate and a rebellious imperial daughter find a connection on the high seas in a world divided by colonialism and threaded with magic. Aboard the pirate ship Dove, Flora the girl takes on the identity of Florian the man to earn the respect and protection of the crew. The brutal life of a pirate is about survival: don't trust, don't stick out, don't feel. When the pirates prepare to sell their unsuspecting passengers into slavery, Flora is drawn to the Lady Evelyn Hasegawa, who is en route to a dreaded arranged marriage with her own casket in tow. The pair set into motion a wild escape that will free a captured mermaid (coveted for her blood, which causes men to have visions and lose memories) and involve the mysterious Pirate Supreme, an opportunistic witch, and the all-encompassing Sea itself.