Demons of the Mind is a horror movie released in 1972. It was directed by Peter Sykes and starred Paul Jones, Gillian Hills, and Robert Hardy. The plot of the movie revolves around a doctor, Dr. Falkenberg (Robert Hardy), who is called to a remote castle in Prussia to treat two siblings, Carl and Elizabeth (played by Shane Briant and Gillian Hills). The siblings are being kept virtually imprisoned in their home by their father, Baron Zorn (Patrick Magee), who believes that they are possessed by demons.
As the doctor begins his treatment, he discovers that there is more to the situation than just mental illness. His investigations uncover a web of sex, incest, and satanic possession. The Baron and his accomplices are involved in a cult that involves human sacrifice and ritualistic sex, and they believe that the siblings are the key to their ultimate power.
The doctor becomes deeply involved in the case, and he starts to unravel the truth behind the Baron's twisted beliefs. As the tension builds and the danger increases, the doctor must use all his knowledge and skill to try and save the siblings from their supernatural fate.
Demons of the Mind is a disturbing and unsettling horror movie that is not for the faint of heart. It contains scenes of violence, sex, and gore that are not suitable for younger audiences. Despite this, it remains a cult classic among horror movie fans, thanks in no small part to its chilling atmosphere, suspenseful storyline, and excellent performances from the cast.