Based on a little known and lesser story by Nikolai Gogol, the film actually improves the original with effectively creepy music (where appropriate), and with special effects that were very good for a movie made nearly forty years ago. The carefully faithful adaptation concerns a seminary student on holiday who is propositioned by a hag who turns out to be a witch. She rides him through the air like a broomstick, and when they land he beats her off with a club only to discover that, near death, she has transformed into a beautiful young woman, the daughter of a Cossack chieftain. Her father sends to the seminary for the student because his daughter requested that only he be summoned to read the prayer for the dead three consecutive nights over her corpse. What happens in the locked chapel until dawn during those nights is what the story is about.
It is as scary as most of the Hammer films of the same era, only with Gogol's trademark sense-of-humor. Hammer would have made the witch more grotesque, and the young dead woman sexier. The only let-down is that Viy's appearance at the end of the movie is not very scary and even somewhat comical. But he's only on screen a few seconds. The creatures that crawl out of the walls ahead of Viy are as grotesque as anything to be found in films of that time, and make the lead-up to Viy's arrival very suspenseful
Unfortunately the B&W beauty of this movie is compromised somewhat by Bava's awkward direction of actors whose performances range from adequate (Andrea Checci as Dr. Kruvaijan, and Ivo Garrani as Prince Vajda) to inept (Barbara Steele as both Princess Katia Vajda and Asa Vajda), to awful (John Richardson as Dr. Gorobec). The writing is likewise sub-par, and seems to borrow elements from the vintage American films "Mark of the Vampire" and "The Black Room," which Bava may have seen.
Plot holes are numerous and obvious. For instance, after draining the life from Katia's father, how does the vampire form of Dr. Kruvaijan find a ready-made coffin, and how does he bury himself? How does Katia's brother Constantine survive a fall down a deep pit to come back and destroy Javutich? The schmaltzy piano love theme is distracting, beginning immediately after Katia's first meeting with Gorobec. Nevertheless, camera poetry abounds. The slow-motion vision of the phantom coach driven by Javutich is a stunner. All of the genuinely unsettling moments are the result of Bava's uncanny use of lighting, shadow, and perspective; not the poor use of artificial-looking wax figures and lens filters to create the effects of aging on Katia's and Asa's face.
Austensibly based upon Nikolai Gogol's short story "Viy," there is only one scene in the film that is recognizable from the source material. The scene in the crypt when Krubaian is alone with, and trying to escape from the reanimated Asa, parallels the attempts of Gogol's protagonist to escape from a witch who has arisen from her coffin. Barbara Steele's makeup, the spike holes left in Asa's face by the mask of Satan, is very effective here.