On the eve of World War I, a reclusive English aristocrat takes in the niece--and near twin--of his fiancée who died just before their wedding. But the same young woman who reawakens the man's heart now threatens to break it again in Smilin' Through. Since Sir John Carteret's (Leslie Howard--Gone with the Wind) fiancée, Moonyean Clare (Academy Award winner Norma Shearer--The Women) died protecting Carteret from a jealous suitor, the aristocrat has led a lonely, reclusive life. But when Moonyean's niece, Kathleen (also Shearer), comes to England, Sir John brightens and starts to live life again. But Kathleen falls in love with Kenneth Wayne (Academy Award winner Fredric March--The Best Years of Your Lives), the son of the man who murdered Sir John's love--and Sir John will do almost anything to quash the love growing between Kathleen and Kenneth.