Adapted from Fannie Hurst's novel, a woman becomes the mistress of an ambitious banker with a family.
In Cincinnati in 1900 the gas buggy of Curt Stanton (Richard Carlson) fails to work, and pretty Rae Smith (Margaret Sullavan) declines to marry him. Salesman Ed Porter (Frank McHugh) asks Rae to go to Dayton, and she slaps him. At the train Rae meets Walter Saxel (Charles Boyer), who takes her to dinner. They talk for hours, and he stays in town. Rae learns that Curt sold his bicycle shop and is going to Detroit. Walter tells Rae he is leaving and has a fiancé in Louisville. Walter calls Rae to the boat; but masher Harry Niles (Frank Jenks) takes her away. Walter plans to wed her but learns she went out with a man, and Rae misses the boat.
Five years later in New York Walter works for banker Felix Darren (Samuel S. Hinds) and has a wife and son. Walter and Rae meet on the street and have dinner. Walter tells her he had arranged to wed her on the boat. Rae is evicted, and with Walter she rents a place as Mrs. Smith. Walter asks Rae if she wants him to divorce, and she says he would lose too much. Ed learns of Rae's situation and advises her against it. Felix and friends take Walter out on New Year's while Rae waits alone. Felix asks Walter to go to Europe for six months with his wife. Walter wakes Rae at 3 a.m. and tells her she can't go with him.
Rae gets postcards. After the summer Curt finds Rae and shows her his car. Curt's car wins a race, and he asks her to marry with a letter. Rae finds Walter in her place and learns he has been back five days and has a daughter. Rae tells Walter she means too little to him. Rae wires Curt she is going back to Cincinnati. Rae tells Ed she is marrying Curt. At the train they meet Walter, and Rae goes back to him.
In 1928 Walter boards a boat and answers reporters. Rae boards alone and is seen by Walter's son Richard Saxel (Tim Holt) and his daughter. Rae tells Walter his speech is good. She gambles, and Richard stares at her. In her room Richard warns her to leave them alone, because his sister is marrying. He offers her money. Walter comes in and tells Richard their story. Richard calls them both rotten. Rae reads that Walter had a stroke. Walter asks Richard to call Rae. Walter tries to talk and dies. Richard gives Rae a steamship ticket and goes for a doctor. Rae imagines what would have happened if she had not missed his boat and then dies.
Sexual harassment causes Rae to miss the opportunity
to marry the love of her life, profoundly altering her fate in
this romantic tragedy that offers an object lesson. Unable to
give him up, she becomes a lonely part-time mistress instead of
the wife of another man.