Andrea Marcocci (Pietro Germi) is a world-weary railroad engineer with several decades on the job. His wife (Luisa Della Noce) feels neglected, and his older son (Renato Speziali) and daughter (Sylva Koscina) have grudges against him. Only Andrea's young son, Sandro (Edoardo Nevola), remains devoted to his father. After Andrea almost causes a collision, his career takes a downturn, and the family crisis ramps up. Then a neighborhood Christmas celebration offers a chance at salvation.