Frances Waring, eighteen, lives with her father in Bordighera Italy. He has never told her about his past, not even what county he is from; and she assumes her mother is dead. It is a shock when a young woman arrives announcing she is Frances's twin sister Constance; and even more of a shock to discover that she has a mother, Lady Markham, and a half-brother, Lord Markham, living in England. Connie has run away from her mother's plans to push her into an arranged marriage.
Frances's world is turned upside down when she is sent to London to live with her mother. She finds "society", as her mother and siblings know it, to be artificial and insincere. Things become much worse when Captain Gaunt, a man she is drawn to, arrives in London and is taken up by Connie and Lord Markham.
This novel is marginally related to A Country Gentleman, but might be better enjoyed as a stand-alone novel.
See "2 Related Story Lines" below.
Biographical and other notes
The novel's title stems from the New Testament: "And if a house be divided against itself, that house cannot stand." (Mark 3:25)