Martin, a director, is visited by his former teacher, who has been suffering from mental illness. The old professor has an idea for a new film: a film about hell and the devil, based on the premise that hell is here on earth and the devil has unlimited power over human lives. Martin mentions the idea to Tomas, a journalist, who writes film scripts. He believes the film could be a success, because he has met the ideal heroine, Birgitta-Carolina. She lives with her protector, Peter, and his sister, who do not hesitate to kill the child Birgitta-Carolina gives birth to. Exasperated, Birgitta-Carolina runs away, encounters Tomas, who is downcast himself after imagining he has murdered his wife, and the two of them live briefly together. But Birgitta-Carolina cannot bear to drag Tomas down with her. They part, and shortly thereafter she commits suicide in a cellar. Tomas returns to his wife. (official distributor synopsis)