In letzter Minute (1939)

A retired rail official and his wife Amalie purchase a disused railroad wagon to convert it into a villa in the countryside. One day, Amalie discovers 25,000 Marks hidden behind a picture in the rail car. The money was put there by a Dutch couple, who tried to smuggle the money across the border during the train’s last journey. Sorely tempted to keep the money, Amalie turns it over to the authorities. The smugglers, who finally find the rail car after a long search, will be turned over to the cops, too.