The Halloween Top 13: The Devil Made Me Do It # 10: To the Devil a Daughter (1976)
Widmark plays supernatural author John Verney. When approached at an art gallery opening by Harry Beddows (Denholm Elliott), Verney agrees to pick up Harry's daughter from the airport in exchange for information on the Satanic Cult that Harry claims is trying to kill him. After picking up Harry's daughter, Catherine (Nastassja Kinski), who he is surprised to find out is a nun, John takes her back to his apartment to await her father. He never comes. The author soon realizes that the cult is not after Harry at all, their target is Catherine. The cult leader, Father Micheal (Christopher Lee), is a heretic priest excommunicated from the church for the worship of Astaroth, the Crowned Prince of Hell. He has already brought about the birth of the demon as a mutant baby, and now he needs Catherine as a human avatar for the lesser God of Hades.