The story is set in the English countryside and revolves around the lives of two sisters, Lady Ingleby and Lady Mildred, who are both in love with the same man, Sir Beverley Shenstone. The book explores themes of love, loyalty, and sacrifice as the two sisters navigate their feelings for Sir Beverley and the challenges that come with their respective social statuses. The story is told through the eyes of Lady Ingleby, who is the mistress of Shenstone and is torn between her love for Sir Beverley and her loyalty to her sister. The novel is a classic romance that is full of drama, suspense, and unexpected twists and turns.