This book is the first novel by American author Willa Cather.
Bartley Alexander is a construction engineer and world-renowned builder of bridges going through what's known today (but not in 1912) as a mid-life crisis. Although married to his wife Winifred, Bartley resumes his acquaintance with a former lover, Hilda Burgoyne, in London. The affair proves to gnaw at Bartley's sense of propriety and honor.
Professor Wilson arrives at the Alexanders' house in Boston, after Mr Alexander has talked him into attending a Congress of Psychologists there. He is greeted by Mrs Alexander; later her husband comes home and they have a talk; his wife plays the piano for them. The next day, she tells him how she met her husband through her aunt.
In London, Bartley Alexander meets with Maurice Mainhall to see a play starring Hilda Burgoyne, an erstwhile lover of his. Back in his hotel room, he thinks back to how he broke up with her in a letter after he met Winifred in Canada. Later, he walks to her house to see where she lives and reminisces about his youth. At a party at Lady Warford's, he talks to her after many years apart and she says she has been reading in the newspapers about his success with bridges in Japan and Canada. Later, he goes to another party also held by Lady Warford. The following Thursday, he takes Hilda to dinner and they reminisce about Madame Anger and Angel, and a beggar they had seen in the street once. He asks her to sing for him and she asks if he will let her love him.
On Christmas Eve, the Alexanders are getting ready for the Christmas dinner, and Bartley tells Wilson he is in trouble with the bridge in Canada. Later, he gives his wife pearl earrings. On New Year's Day, Alexander is getting ready to leave for London again. Later, on the ship, he battles with sharp gales and goes into a bar, where he gambles at bridge. Once in London, Bartley visits Hilda and tells her he cannot go on having two relationships; she must forget about him and leave him alone. She is distressed. The day before he is due to return to America however, he takes her out to dinner.
Later, Hugh MacConnell walks Hilda back to her house on a foggy day, and she says she isn't attracted to him because they are just close friends. Back in her house, she receives a letter from Bartley, saying he is going mad away from her. This prompts her to visit him in America to tell him she will marry another man and thence be bound to someone else; he doesn't like the idea. They spend one last evening together.
Soon after, Bartley is called to Canada by Philip Horton to inspect the bridge. Bartley discovers that one of the lower chords of the bridge was failing, compromising the structural integrity of the entire bridge. Horton was afraid to halt construction, but had first attempted to contact Bartley even earlier - the very day Bartley was with Hilda. As Bartley is on the bridge stopping the work crews, the bridge collapses, killing many of the workers. Bartley's body is recovered the next day and taken to Horton's house. Winifred comes back to look after the dead body. Finally, Wilson visits Hilda. The latter expresses her jealousy over Winifred, but Wilson reminds her that she will not live again, she will be haunted by her husband's death. Hilda concludes that she will be too.