Louis Trevelyn, a wealthy and respected Englishman, marries the poor, but spirited, Emily. They live happily together for about a year, and have a son. Emily begins to accept regular visits from Colonel Osborne, an old friend of her father’s, who claims to visit Emily only as a family friend. However, his age sits lightly on him and he has a reputation for breaking happy homes.

Louis, in a jealous rage, instructs his wife to refuse all further visits from Osborne. Emily believes that he is accusing her of infidelity and is extraordinarily angry. She insists that Osborne is simply a friend. Neither partner will apologize. Eventually, Louis can no longer live with his wife. He sells the house, sends Emily and Louis, Jr. to live in the country and sets himself up in a squalid boarding house.

Emily does not wish to be separated from her husband and grows less prideful. She will gladly obey Louis’ command to no longer see Osborne, but she will not apologize for having seen him, as she believes it would be tantamount to confessing adultery. Louis, meanwhile, grows increasingly obsessed with her "disobedience" and hires a private detective to keep an eye on his wife. The detective finds that Osborne insisted on a visit to Emily--  visit that was public and lasted ten minutes, but that nevertheless leads Louis to steal his son and flee to Italy.

Louis’s obsession makes him mentally and physically ill. When Emily and her family track him down in Europe, he is deathly thin and seems mad, convinced that his wife, his friends, and even the private detective are against him. This wretched marriage is contrasted to several other relationships that develop in the course of the novel. These are based on mutual respect and love rather than self-pride and so flourish. These happy couples also physically and mentally change, but for the better.