Sixth-year student Eva Martenová falls in love with the new young professor Jiří Hron. She cannot concentrate in his lessons, even though she is as well prepared as ever for teaching. On a school trip, Professor Bruncvíková tries to win Hron over, but the professor dances with Eva at a party. At school, Eva's thoughts are elsewhere again and she refuses to give Bruncvíková Hron's portrait. She goes to Hron's office crying and he tries to calm her down. His friendly gesture is seen by Professor Bernard, who had previously had reservations about Hron's modern teaching methods. He informs the principal that Hron was holding student Martenová in his arms. When Eva learns that Hron is facing disciplinary proceedings because of her, she attempts suicide. However, her friend Martina's brother, Dr. Pavel Haler, saves her. In the hospital, Eva is visited by a vindicated Hron and confesses his love for her.

Irča Miňovská, the daughter of a car factory director, meets mechanic Lexa Hora by chance. They fall in love, but Irča's father does not want his daughter's unequal relationship and decides to send Irča to a boarding school so that she cannot see Lexa. Lexa leaves the plans for her new engine with her boyfriend Harry Peters at the factory, resigns, and leaves to forget about Irča. Director Miňovský would like to produce a new type of engine, but Lexa is nowhere to be found...

The wealthy factory owner Osten has achieved his position thanks to his energy and diligence. However, he has one weakness - he cannot admit that he too must grow old one day. What scares him most is the thought of becoming a grandfather. To prevent this, he is willing to become a rival in love with his own son. One day, Jiří has ​​had enough of his father's actions and decides to leave his house and his comfortable life. He even changes his name and starts working in a competing factory as an ordinary worker to prove to his father that he too is capable of working his way up from scratch. That is when Jiří meets the energetic seamstress Tonička, who is studying in the evenings to become an office worker. The young people are happy together, but the factory owner Osten comes between them. He offers Tonička a position as a secretary and is ready to win her over...

An old peasant from Chodský, Záhor, claims to the young Podestát that he returned three hundred gold pieces to his father before the old Podestát died. Out of greed, Záhor even decides to perjure himself in court. The indignant creditor warns him of God's wrath. Záhor's sons, Matěj and Vondra, are vying for the same girl - the daughter of a blacksmith, Nana.