An Angel and the Devil observe the residents of Belgrade, trying to influence their actions and betting on them. Among them is Nikola, a 20-year-old playboy and literature student who has already slept with almost half of the girls in the city. On one occasion, he gets so drunk that he forgets he spent the night with an otherwise very unremarkable and unattractive girl, Marina. Unbeknownst to him, she became pregnant. Since Marina does not want to have an abortion, her friend Buba tries various tricks to make Nikola fall in love with Marina. When he finally learns about the pregnancy, he tries to persuade Marina to have an abortion, but she refuses. In the end, Marina gives birth to a baby girl, Sofia, and Nikola has to take responsibility and be with her, and realizes, to his shock, that his daughter may one day become a 'victim' of seducers like him. Satisfied with the outcome, the Angel concludes that he won the bet.