Director Ulli Lommel was unsure about casting Klaus Kinski, but he met him and Kinski was very nice, according to Lommel. But when the filming started, Kinski was very hard to work with. He complained about the lights and microphones, so eventually they had only few soft lights and very small microphones in the Kinski scenes, which is the reason why the sound quality changes much in different shots. Kinski also didn't want to sit on a chair when camera crew was about to shoot from different angle, so continuity wasn't possible. Because of that Lommel decided to change Kinski's character to a ghost, which was a brilliant idea in Kinski's opinion. Later he was so happy with the director that he said he doesn't work in the future with anyone else than Lommel, but Lommel's answer was simply "Yeah, right".
Ulli Lommel always intended the uncle as a ghost. The only difference was the character was also supposed to be a guy with a great sense of Irish humor, to give the movie a more comical feeling. Lommel wanted the film to be more of a slapstick comedy as it was originally supposed to be an upbeat adventure yarn. But when Klaus Kinski was brought on to portray the character, his take on the uncle totally turned the mood of the picture, making it more darker. With the short budget and tight deadline to finish the film, Lomell was stuck with the new approach to take.
According to his autobiography, Klaus Kinski had an on-set affair with "Suky" (clearly Suzanna Love)."There I fuck the director's wife one more time. The surprises women give never end: I don't think there is any woman in the world with longer pussy hair than Suky. In the upper area of her pussy and around the lips of her vulva, she has them so long that I make braids with them."- Kinski wrote.
Ulli Lommel, the film's director and Suzanna Love's husband, confirmed the story, revealing disturbing details. "My second wife was the actress and Standard Oil heiress Suzanna Love. When she shot 'Revenge of the Stolen Stars' under my direction in 1984, she fell for my leading man Klaus Kinski. [...] When the movie was finished, Suzanna flew with him to his magnificent villa in San Francisco. Why, you have to ask her. She quickly realized that she was a prisoner, because Klaus treated her like Natascha Kampusch. When he went shopping, she was bound and gagged. He probably saw it as love play. When she was able to make a phone call in an unguarded moment, she told me: 'Please come and free me immediately! Klaus keeps holding his revolver to my head and threatening to kill me.' I hired a bodyguard who brought two guns. When Klaus opened the door, the bodyguard hit him in the face with his fist. Seeing the paranoid monster unconscious on the floor was a nice compensation for the most horrible shoot of my life," Lommel said.
When the producers hired Ulli Lommel to make the film, they told him they wanted a film in the style of All'inseguimento della pietra verde (1984). Lommel initially went along with their wishes but halfway through filming he began to grow bored with making a routine adventure movie and decided to add supernatural elements and gory deaths into the film, all in the same vein of his earlier film Mirror: Chi vive in quello specchio? (1980) but restrained to fit the PG-13 rating, as well as throw in a martial arts sequence to make the movie stand out as a whole.
The script was initially 60 pages.