Cecile has been raised to a life of privilege at Polruan House by her widowed father and aunt. Now she's of age they are determined that she make a proper match but Cecile's heart belongs to their coachman Sam. When Sam turns to his friend smuggler Zach Carver for help eloping with Cecile Zach tells of a recent encounter with Lise a beautiful but poor girl in St Ives who is the mirror image of Cecile. And so a plan is born to briefly swap the girls. But bringing Cecile and Lise together will uncover an astonishing family secret of a bold escape from a loveless marriage a treacherous shipwreck and a sister thought lost to the sea long ago . . .