A woman accepts life in the shadows as the price for her affair with a married man.

In Cincinnati at the turn of the century, aspiring automobile manufacturer Curt Stanton leads a parade to introduce the city to his new horseless carriage. Although Curt had hoped to gain financial backers, the car breaks down directly in front of a bank. Curt, now a laughingstock, pushes the car back to his bicycle shop, where his passenger, shop girl Ray Smith, tries to comfort him. Curt proposes to Ray, but is turned down as usual. Later that evening, Ray visits with her traveling salesmen friends, including Ed Porter. Ray then takes Ed to the railway station, where she meets investment banker Walter Saxel. Walter and Ray immediately fall in love, causing Walter to postpone his trip to New Orleans. Ray's dreams of marriage are shattered, however, when Walter admits that he is engaged to his boss's niece and breaking the engagement would ruin him socially and professionally. Walter leaves to catch his boat but has a change of heart, calling Ray and begging her to meet him. He then arranges two passages and hires a justice of the peace. Ray misses the boat, however, after salesman Harry Niles abducts her and she is forced to walk back to town for refusing to submit to his desires. Ray then watches brokenheartedly from the docks as Walter's boat sails away. Five years later in New York City, Walter runs into Ray on the street. Despite his marriage and young son, Walter and Ray immediately fall back in love and Ray becomes Walter's mistress. Thrown out of her apartment because of the affair, Ray moves into another apartment, where Walter is accepted as "Mr. Smith." After two years, Ed finds Ray and, when he learns of her arrangement with Walter, begs her to leave, offering her a job as a clothing designer. Ray refuses and continues as Walter's mistress. Walter is forced by his uncle to take a prolonged business trip to Europe with his wife, and Ray waits endlessly for his return. Curt, now a great success in the automotive field, arrives at their apartment and takes Ray out for her first night on the town in years. Curt proclaims his love, but rather than proposing in person, offers to write her of his desires. Returning to her apartment, Ray finds Walter waiting, but her joy is shortlived when she learns that Walter's wife bore him a daughter during the trip. Ray then decides to leave Walter and returns to Cincinnati. Ed arrives in town and learns that Ray is going to Detroit that night to marry Curt. At the railway station, Ray and Ed are confronted by Walter, and she once again goes back to the banker. Years later, in 1928, Walter and his family board a boat to Europe, where Walter will head an American banking commission in Geneva. Also boarding the ship is Ray, whose relationship to Walter is now common knowledge. With Walter away at the conference, Ray is confronted at their Paris apartment by Richard, Walter's grown son. Walter returns unexpectedly and tells his son of their longtime love, but Richard is not moved and proclaims his disgust with his father. After Richard leaves, Ray learns that Walter has been removed from the commission due to their relationship, and the weary Walter leaves, promising to see her the next day. When Ray opens the newspaper the next day, however, she learns that Walter has had a "paralytic stroke." On his deathbed, Walter calls Ray and dies as she listens on the phone. Days later, Richard visits the heartbroken Ray at her apartment. Ray proclaims her love for Walter, speaks of what would have happened if she had not missed the boat years ago, and dies with Walter's picture in her arms.