Mrs. Foster is an elderly woman who has lived in quiet obedience to her husband for decades. She possesses a nearly pathological fear of being late for trains and planes, an anxiety that physically manifests as a prominent eye twitch when she is delayed. Beneath her dutiful exterior, she harbors a deep loneliness and a quiet yearning to live in France near her grandchildren.

Mr. Foster is a 70-year-old, affluent man who lives with his wife in a large New York home. He maintains an outwardly polite and unhurried demeanor that masks a cruel, controlling nature. He consistently leverages his wife's fear of lateness against her, analyzing her resulting physical distress with quiet satisfaction.

Walker is the butler in the Fosters' New York home. He manages the household logistics and discreetly attempts to assist Mrs. Foster with her departure, stepping in to prompt Mr. Foster when Mrs. Foster is too frightened to do so herself.

The Irish Chauffeur is hired to transport the Fosters to the airport for Mrs. Foster's flight. He observes the tense dynamic between the couple from the driver's seat and becomes the sole witness to Mrs. Foster's sudden shift in behavior on their second attempt to reach the airport.

The Fosters' adult daughter lives in Paris with her husband and three children. She communicates with her mother through letters and photographs, providing Mrs. Foster's only source of joy and motivation for her transatlantic journey.