Three friends - Tomás, Hubert and Jozka - are boys growing up in a little town. Tomás lives with his aunt Apolena and uncle Václav. Tomás is a boy with lots of ideas that often end up getting him into trouble not only with his teachers and aunt, but with the other inhabitants of the town as well. He has a crush on his schoolmate Blanka and for her sake he decides to try to get the prize for the best pupil in the school.

A trespassing gang of boys encounter a ghost in the ruins of a castle. When they rescue the ghost who is caught in a trapset, they become allies in a fight to prevent ruins from being turned into mushroom farm by the city authorities.

Children from the village Bystrá are awaiting a nice and thrilling weekend. On Saturday they will play the championship football match with the nonresident boys from the village Skuhrov, on Sunday there will be the funfair with merry-go-round, swings and stalls with dainties. The members of the family of the merry-go-round man are brother and sister Janek and Zaneta Mareks whom the children have known since the last year. At that time Zaneta made friends with girls and Janek, an excellent football player, has been a welcome support of the football club.

Ten-year-old Frantisek is traveling to Leipzig to visit his German friend Egon. On the train, he shares the compartment with three men. One of them, the bearded, hefty Blasius is polite but at times acts very confused. At the end station the two boys meet, but they must first of all get rid of Blasius, who lifts them up together with their luggage and carries them away. Leipzig is packed with tourists who have gathered for the famous Fair. The eccentric bearded fellow deals effectively with the traffic jam in front of the station. Blasius's fellow travelers from the train - inventors Prantl and Pirwitz, are at the fairground, boasting of their new invention and claiming it to be the greatest surprise of the entire Fair.

The town is waking up. The bus driver Josef Král is saying goodbye to his wife Vera who is in a state of advanced pregnancy. At the rolling mill, the master craftsman Mares is preparing for retirement, which is now only two days away. Elderly Simon who grows and sells vegetables at the market has problems with his wife. Their little home has to give way to a new development but the wife Simonka refuses to move out. The chairman of the workers' council has troubles with the miner Adam, who has started drinking. He doesn't know that Adam is getting divorced and fears he may lose his young son to his wife.