A tranzitutas (1983)

One night the upper-level neighbor knocks on the door of a screenwriter in crisis and asks for help, as she found a dead body in her apartment. The screenwriter believes that he is his long-lost father. He investigates to find out the exploits he had heard about him from his mother and is planning to write a masterpiece about him. As he delve deeper into the story, it turns out that his father wasn't a hero, not even a good man. His boss at the film factory steals his idea.