There are so few great films about witches. Two early films that come to mind are Witchfinder General (1968) starring Vincent Price in the title role and Night of the Eagle (1962, whose American title is Burn Witch Burn) written by Richard Matheson. These great films about witches aren't even as much about witches as they are about the people who suspect the witches of doing evil things and the people who hunt them. They are about fear and paranoia. In 1977, Italian horror director Dario Argento made Suspiria. This was the first of what was to be a trilogy known as The Three Mothers trilogy, which was only completed in 2007 with The Mother of Tears. The second film in the trilogy is Inferno (1980). This one more than the other two remind me so much of those films about witches from the 1960's, because most of the film involves searching for answers and the obstacles that stand in the way. The presence of witches is very minimal in the film. And that certainly isn't a bad thing.
While this film has been classified as horror over the years, I think after the horror of Suspiria, this deviates a little away from the genre and is more of a mystery that is filled with suspense and a few horrific scenes. At the heart of the film is the search for missing people as well as the meaning of the mysterious book called The Three Mothers. The film starts with Rose (Irene Miracle) finding the book. She has reason to believe that she is living in one of the houses that is described in the book. The author gives instructions on where to find important keys. She spends a lot of time looking around in brightly colored but darkly lit hallways. And she falls into a ballroom filled with water where she finds a withered up corpse. She writes a letter to her brother Mark (Leigh McCloskey) and tells him that he should come visit her. Before he has a chance to arrive, two people who go to school with him are murdered and his his sister disappears. Now Mark must find is sister who may already be dead and he must figure out the meaning behind this book.
The score in Inferno was done by Keith Emerson of progessive rock band Emerson, Lake and Palmer. The Goblin score in Suspiria is much scarier and much louder, but Emerson's score is very effective too.
The atmosphere Inferno isn't quite as ominous and grande as Suspiria. Overall I would say that Suspiria is a much better film. But Inferno serves a different purpose and it fulfills that purpose as good as it possibly can and it is a great film. Saying Suspiria is better than Inferno is sort of like saying The Godfather Part II is better than The Godfather. Both films are a masterpiece and it's just a matter of taste as far as which one you think is better.