All the colors of the dark (1972) HD

Storyline: Due to a trauma suffered as a child (she witnessed the murder of her mother), aggravated by the recent death of the child she was carrying in a car accident, young Jane Harrison lives in an atmosphere of constant tension. For some time now her nightmares have materialized, taking the form of an unknown dagger-wielding hitman who haunts her relentlessly. Recommended by her sister Barbara, Jane turns to a psychiatrist, Dr. Burton, with whom she begins a series of therapeutic sessions. In the meantime, she meets Mary, a mysterious woman who has recently moved into the same building as her, who, guaranteeing her liberation from every nightmare, induces her to take part in the black masses of a sect of Satan worshipers. The new experience shocks Jane's mind even more. After Doctor Burton and two old spouses - to whom the same doctor had entrusted the young woman - are found mysteriously killed, Richard, Jane's husband, and the police manage to identify the participants in the black masses and arrest them. Jane's nightmares were the result of a diabolical conspiracy put in place by her sister Barbara to snatch away an inheritance of three hundred thousand pounds, left by their mother's murderer as partial reparation for her crime.