Sisif, a railwayman, saves a young girl named Norma orphaned by a train crash and raises her as his own daughter alongside his son, Elie. As she becomes an adult, Sisif grapples with whether to tell Norma the truth about her parentage.
Returning by train to the French port of Le Havre, Jacques Lantier, a tormented railwayman, meets by chance the impulsive stationmaster Roubard and Séverine, his wife.