Hosted by Boris Karloff (who also appears as a performer), Mario Bava's horror anthology Black Sabbath is a stunning work of horror. Following in the footsteps of the other huge anthology of the time, 1946's Dead of Night (which was the first film in my knowledge to actually show the inherent terror in ventriloquist's dummies), Bava and his co-writers have crafted a wonderfully frightening trio of horror stories. Though the first two contain slightly less scares, the final story is absolutely terrifying (and literally had chills running up my spine).
The first story is entitled "The Telephone" and tells the story of Rosy (Michele Mercier), who has been getting harassing phone calls from an unidentified assailant who wishes her dead. When she discovers that her imprisoned husband has recently escaped, she fears that he may be the one stalking her. Relying on the comfort of a jilted lesbian lover, Mary (Lidia Alfonsi), Rosy prepares for the worst.
The plot of "The Telephone" contains a few twists that allow for some pretty effective chills, but ultimately the ending of the story is pretty evident. The premise of a woman being tortured by harassing phone calls probably won't seem relevant to those who have grown up in the era of the Scream trilogy, but Bava still manages to generate a real terror of ringing phones. This story could also be seen as the forerunner of all of the "the calls are coming from the attic" type stories and films that were prevalent in the seventies.
The second story is called "The Wurdalak" and is supposedly based on a story by Tolstoy. The segment features Boris Karloff as the patriarch of a family who has been in the grip of terror over a Wurdalak (or vampire) that has been rampaging across the countryside and feeds on the people it loved the most while alive. He departs to destroy the vampire and tells his family that if he has not returned within exactly five days he must not be allowed back in if he does eventually return. When he shows up just minutes after midnight on the fifth night, his family wonders whether or not he has been turned into a Wurdalak and if it was wise to allow him back into their home.
"The Wurdalak" has a few chilling moments, such as the vampiric child of the family standing outside his parents' home calling out to his mother to bring him in from the cold. There is also a wonderful atmosphere surrounding this segment and it really shows off the wonderful cinematography work Bava's films are known for. Though this segment is as obvious to figure out as the previous one, the visuals are remarkable and worth seeing.
The third segment is by far the most terrifying. Entitled "The Drop of Water" and credited to the writings of Anton Chekhov, this story concerns a nurse named Helen Corey (Jacqueline Pierreux) who is called upon by a maid to dress the corpse of the medium who's home she was the caretaker for. She agrees, despite the fact that it is very late at night and storming badly, but she wants to be compensated heavily for her time. The maid (Milly) promises to pay her well, but she spies a ring on the corpse's finger that her covets more and steals it while the maid is in another room. Upon returning home, Helen is haunted by the corpse of the medium, who wishes to be vindicated for the theft of her ring.
Thanks to some truly frightening make-up work, "The Drop of Water" segment ends up being one of the most chilling scenes I have ever seen in a horror film. The medium's twisted face is grotesque to the extreme and I have never seen a visage as terrifying as the one presented here. The mask was designed by Bava's father Eugenio, and is one of the greatest accomplishments of cinematic horror make-up to date (especially when compared to the almost cartoonish make-up of today's horror film villains).