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.