Fanatyk is a comedy-drama film that tells the story of a neurotic man who becomes obsessed with literature and addicted to the internet. The film explores themes of addiction, family relationships, and the struggles of a neurotic individual. Through various events and flashbacks, the film follows the protagonist's journey as he navigates his obsession with literature, his addiction to the internet, and his relationships with his family and friends.

Kuba is undergoing mandatory addiction therapy when he is kidnapped by his eccentric uncle – a conspiracy theorist who believes in the imminent end of the world. The uncle and his team of journalists from the "Prawda TV" channel want to involve him in their secret plan to prove that the mayoral elections were rigged. Initially skeptical of his uncle's obsession, Kuba discovers that the village is threatened with a real ecological disaster and decides to act. The situation is further complicated by his former love, Gośka. All this forces him to take matters into his own hands and make decisions that he has been running away from so far.