Here is the Wiki plot synopsis for the novel –
Set in 1930s London and the South of England, Duc de Richleau and Rex van Ryn rescue their friend Simon Aron from a devil-worshipping cult. Rex falls in love with another initiate of the cult, Tanith. Rex prevents Tanith from going to a ceremony on Salisbury Plain. The Duc and Rex rescue Simon from the ceremony. They escape to the home of the Eatons, friends of Richleau and van Ryn, and are followed by the group’s leader, Mocata, who has a psychic connection to the two initiates. After visiting the house to discuss the matter and an unsuccessful attempt to influence the initiates to return, Mocata forces Richleau and the other occupants to defend themselves through a night of black magic attacks. During this Mocata summons the Angel of Death using the medium of Tanith. The defeat of the Angel results in Tanith’s death. After successfully defending themselves through the night the group find that Mocata has kidnapped the Eatons’ daughter. Simon exchanges himself for her. Mocata is using Simon to find the Talisman of Set, a powerful satanic object. The book culminates in a desperate chase across Europe to an abandoned Greek Monastery where Mocata is defeated. The group wake up in the Eatons’ home and realise that during the ceremony they entered the fourth dimension. Mocata is found dead outside the house. The Duc wakes up clutching the Talisman and destroys it. Tanith is found to be alive – Mocata’s soul has been exchanged for hers.
The Hammer film, starring Christopher Lee was released in 1968.
Here is the Wiki plot synopsis for the film –
Set in 1930s London and the south of England, the story finds Duc de Richleau (Christopher Lee) investigating the strange actions of the son of a friend, Simon Aron, who has a house complete with strange markings and a pentagram. He quickly deduces that Simon is involved with the Occult. Richleau and Rex van Ryn rescue Simon and another young initiate, Tanith, from a devil worshipping cult. During the rescue they disrupt a ceremony on Salisbury Plain in which Satan himself appears. They escape to the home of the Eatons, friends of Richleau and van Ryn, and are followed by the group’s leader, Mocata, who has a psychic connection to the two initiates. After visiting the house to discuss the matter and an unsuccessful attempt to influence the initiates to return, Mocata forces Richleau and the other occupants to defend themselves through a night of black magic attacks, ending with the conjuring of the angel of death. His attacks defeated, Mocata kidnaps little Peggy. Simon tries to rescue her, but is recaptured by the group. The Duc, Richard, and Peggy’s family, also try to save her, but they are defeated by Mocata. Suddenly, a powerful force, possibly Hecate, the queen of all witches and ruler of all magic, possesses Mrs. Eaton and puts a stop to Peggy’s trance. She then leads Peggy in the recitation of a spell, which kills all of the cultists and transforms their coven room into a church. When the Duc and his companions awaken, they discover that the spell Peggy was led into casting has reversed time and changed the future. Simon and Tanith have survived, while Mocata’s spell to conjure the angel of death has been reflected back on him. He now pays the price of loss of life and eternal damnation of his soul for having wrongly summoned the angel of death.
Here’s a taste of the trailer for the film –
And here is the full 90 minute film. Enjoy !