It's the mid-1800s. Dr. Moira Kelly has completed her schooling at the New York School of Medicine and is looking to return home to London, and her fiancé, Henry. Three years away from home has garnered Moira an independence she never thought possible, and she wonders if this new independence will go over well with her beloved fiancé. Aboard The Persephone, the only ship that will take her on as passenger, Moira befriends the handsome and dashing young sea captain Morgan McKenzie with his eye-patch, piercing green eye, and neatly trimmed moustache. Moira's captivation with Morgan turns to shock when McKenzie reveals he is, in actuality, a woman. Will Moira be able to return home to marry Henry and live the life her parents have planned for her in London? Or will she find her heart spirited away to the depths of the sea?