Last and perhaps tamest of the already Karnstein trilogy of vampire films that was put out by Hammer during the latter years of the horror film company. The films pit good, God-fearing English Christians against the evil Karnstein vampire clan in 19th Century Europe.
Starring Mary and Madeleine Collinson—the first twins ever to appear concurrently as Playboy Centerfolds— as twins targeted by the vampires, this might be the best of the trilogy in terms of story, which isn't saying a whole lot. The twins move into the home of their uncle, a crazed puritan (Cushing) who heads out every night with members of the Brotherhood, looking for witches to burn. Most of the witches they find are just immoral local girls.
The one real devil worshipper they know about is Count Karnstein, who lives on top of the hill in a typical Hammer horror castle. Unfortunately, the count's political connections prevent them from doing what they want to him: Burning him alive. The count eventually sacrifices a town tramp to the devil, and resurrects the body of his ancestor, Mircalla, the lesbian vampire who was the cause of so much trouble in the first two films in the series ("Vampire Lovers" and "Lust for a Vampire"). She turns him into a vampire, and swiftly exits the picture. Count Karnstein becomes the target of desire of the wickedest of the two twins, whom he also converts to vampirism. The climax is pretty predictible.
Less sexy than the other two in the trilogy (there's only one brief nude scene toward the end), this does boast a better story, and Cushing is always a pleasure to watch. He doesn't normally get to play religious fanatics. This time his character was clearly inspired by Vincent Price in "Witchfinder General."
Hammer fans will certainly like this as it's one of the studio's last period films, before they started setting their movies in modern times and eventually went out of business. But casual fans won't be impressed. Director Hough also made "The Legend of Hell House" and "The Incubus."