Curse of the Crimson Altar is a 1968 British horror film directed by Vernon Sewell and starring Christopher Lee, Boris Karloff, Barbara Steele and Mark Eden. The film was produced by Louis M. Heyward for Tigon British Film Productions. The film was edited and released as The Crimson Cult in the United States. The screenplay, by Doctor Who writers Mervyn Haisman and Henry Lincoln, was based (uncredited) on the short story "The Dreams in the Witch House" by H. P. Lovecraft. This film also featured the final British film appearance of horror icon Karloff. The film opened in England in December 1968, then later premiered in Los Angeles on April 15, 1970 on a double bill with Horror House starring Frankie Avalon. It later went into general release across the United States on Nov. 11, 1970, on a double bill with Count Yorga, Vampire. Plot synopsis Antiques dealer Robert Manning (Eden) searches for his brother, who was last known to have visited the remote house of Craxted Lodge at Greymarsh, their family's ancestral town. Arriving at night, he finds a party is in progress, and he is invited to stay by Eve (Wetherell), the niece of the owner of the house. His sleep is restless and strange dreams of ritual sacrifice disturb him. Enquiring about his brother, Peter, he is assured by the house owner, Morley (Lee), that the man is not there. Manning's suspicions are aroused by nightmarish hallucinations. Occult expert Professor Marsh (Karloff) informs Manning about a witchcraft cult led by Morley's ancestor, Lavinia (Steele). With the vicar's help the cult is discovered to still be active. In an effort to kill both Robert and Eve, the modern and righteous descendant of Lavinia, Morley sets fire to Craxted Lodge but is trapped on the roof. He is actually the head of the cult, the ancestral witch Lavinia, who, laughing at the bystanders, is consumed in the flames. Cast Christopher Lee – Morley Boris Karloff – Professor John Marsh Mark Eden – Robert Manning Barbara Steele – Lavinia Morley Michael Gough – Elder Virginia Wetherell – Eve Morley Rosemarie Reede – Esther Derek Tansley – Judge Michael Warren – Chauffeur Ron Pember – Petrol attendant Denys Peek – Peter Manning Rupert Davies – The Vicar Production The house used for Craxted Lodge is Grim's Dyke, the allegedly haunted former home of William S. Gilbert, located in Old Redding, Harrow