Flame-haired Irish lass Mara Despencer embarks upon a plan to take back her family's castle, Kulhaven, after it was confiscated by the English government under Oliver Cromwell's brutal Protectorate. She will lure the castle's new master, the scandalous Hadrian Ross, the Bastard Earl of St. Aubyn, into a marriage that will allow her to become mistress of Kulhaven once again. She thinks to avenge the wrong done to her family, but she soon learns not everything is as it seems with her new husband. In a maze of danger, secrets and intrigue, Mara and Hadrian will have to find a way to work together in a plot that could change the course of history, and see a "merry" prince restored to his throne.