Lady Sarah Baines was devoted to her mother and her family home, Chavensworth. Douglas Eston was devoted to making a fortune and inventing. The two of them are married when Lady Sarah's father proposes the match and threatens to send Lady Sarah's ill mother to Scotland if she protests.
Douglas finds himself the victim of love at first sight, while Sarah thinks her husband is much too, well, earthy for her tastes. Marriage is simply something she had to do to ensure her mother's well-being, and even when her mother dies in the next week, it's not a sacrifice she regrets.
She cannot, however, simply write her mother's relatives and inform them of her death. She convinces Douglas - an ex pat Scot - to return to Scotland with her, to a place called Kilmarin. At Kilmarin, she is given the Tulloch Sgàthán, the Tulloch mirror. Legend stated that a woman who looked into the mirror saw her true fate.
Douglas and Sarah begin to appreciate the other, and through passion, Douglas is able to express his true feelings for his wife. But once they return to England and Douglas disappears and is presumed dead, Sarah has to face her own feelings for the man she's come to respect and admire.