One class of school children from a small village make the trip to Zagreb. One of the boys gets sick and the class is forced to go home. During their journey the train gets stuck in a snowstorm.
The Prague Grand Orchestra travels by train to a music festival in Yugoslavia. Only the singer Sona Klánová missed the departure. In the meantime, she managed to buy a ticket to Belgrade at the air-terminal from Mrs Navrátilová, who couldn't make the trip. In the meantime, the orchestra conductor is beside himself with despair. He phoned to Prague from the border, and when he realized that Sona had left her house in a taxi, he thought that she would catch up with them by the road. The orchestra delayed the train's departure with an improvised concert for the custom officers and the passengers.
