Build a movie plot around this: What is Berti's obsession? Neal's novels
The answer to this question is:
Peter Neal (Anthony Franciosa) is an American writer of violent horror novels whose books are tremendously popular in Europe. In Italy to promote his latest work, entitled Tenebrae, he is accompanied by his literary agent Bullmer (John Saxon) and his adoring assistant Anne (Daria Nicolodi). He is unaware that he is also being followed by his embittered ex-wife Jane (Veronica Lario). Immediately prior to Neals arrival in Rome, a beautiful young shoplifter (Ania Pieroni) is brutally razor-slashed to death by an unseen killer. The murderer sends Neal a letter informing him that his books have inspired him to go on a killing spree. Neal immediately contacts the police, who put Detective Giermani (Giuliano Gemma) in charge of the investigation, along with the detectives female partner Inspector Altieri (Carola Stagnaro).More killings occur. Tilde (Mirella D'Angelo), a beautiful lesbian journalist, is murdered at her home along with her lover. Later, Maria (Lara Wendel), the young daughter of Neal's landlord, is bloodily hacked to death with an axe after stumbling into the killer's lair.Neal notices that TV interviewer Christiano Berti (John Steiner) appears to have an unusually intense interest in the novelist's work. At night, Neal and his second assistant Gianni (Christiano Borromeo) watch Bertis house for suspicious activity. Neal decides to separate from Gianni in order to get a better view. Alone, Gianni watches in horror as an axe-carrying assailant brutally hacks Berti to death. But he is unable to see the murderer's face. Gianni finds Neal unconscious on the lawn, having been knocked out from behind.Giermani's investigation reveals that Berti was unhealthily obsessed with Neal's novels, and now that he is dead it is believed that the killings will cease. However, Bullmer, who is having an affair with Jane, is stabbed to death while waiting for his lover in a public square. Gianni is haunted by the thought that he had seen, but did not recognize, something important at Bertis house during the night of the...