Mario Bava is rightly considered a master of horror, who made a huge contribution to the development of the genre and is considered the founder of 'giallo' (see 'The Girl Who Knew Too Much'), and the movie 'Three Faces of Fear' is called one of his best works. The movie consists of three different novellas that are supposedly based on the works of the classics. Although in fact only the second novel ('The Ghoul') is based on Tolstoy's 'The Ghoul Family'. I'll tell you more about each of the novellas.
1. 'Telephone'.
A young girl is threatened over the phone by her escaped boyfriend, whom she herself has turned in to the police. Essentially a novella, not scary, but great at keeping you in suspense. By the way, part of its plot was copied by Wes Craven for the opening scene of 'Scream'. Basically a good atmospheric story with an interesting ending.
2. 'Ghoul'.
In the second novel a young boy stays overnight in the family, the head of the family (beautifully played by Boris Karloff) which went to kill a Turkish bandit (and partly ghoul) terrorizing the area, which he safely succeeds, but he returns home already another ... Strong and scary story, which is realized thanks to the excellent performance of all the actors and interesting plot.
3. 'The Drop'.
In my opinion, the best story of the movie, in which a nurse dressing up a dead old woman steals her ring, which she soon regrets, because the old woman was a famous witch. The most atmospheric and scary part of the movie keeps your eyes glued to the screen, not letting go for a second.
Mario Bava's true masterpiece 'Three Faces of Fear' becomes such a masterpiece thanks to the director, camerawork and acting, which are truly timeless. The movie looks easy and in one breath after more than forty years. The ending of the film deserves special praise, which is done in a somewhat humorous way (Boris Karloff, riding us on a horse, informs us that the nightmares are over. The camera pulls back and we see that instead of a horse, the horse is a moulage, and the 'forest' he seems to be riding through is just a few people with branches running around in a circle.