The year 1910: When Prince Georg, nephew of the Grand Duke of Baden-Werrach, realizes that an actress he supported and loved was only taking advantage of him, he and his friend, the poet Dr. Richard Hebele, retire to his castle in the Black Forest. On the way to Kaltenau, not far from the castle, he meets Barbara, the postwoman who drives the Black Forest stagecoach. The coach is about to be replaced by a bus, according to the progress of the project.