With the success of Suspiria, Dario Argento had to come up with something equal, if not superior, to his gigantic film.Capitalizing, Argento and Daria Nicolodi, who had co-written the screenplay, announced that Suspiria was only the first of a proposed trilogy, which they referred to as "The Three Mothers" trilogy.
When Argento proposed Inferno as his follow-up to Suspiria, Twentieth-Century Fox agreed to co-finance the production. Nicolodi devised the original story concept, but received no on-screen credit for her work on the screenplay. Nicolodi explained that she did not seek credit because "having fought so hard to see my humble but excellent work in Suspiria recognized (up until a few days before the première I didn't know if I would see my name in the film credits), I didn't want to live through that again, so I said, 'Do as you please, in any case, the story will talk for me because I wrote it.Working from Nicolodi's original story notes, Argento wrote the screenplay while staying in a New York hotel room with a view of Central Park.
The story itself concerns a young man's investigation into the disappearance of his sister, who had been living in a NYC apartment building that also served as a home for a powerful, centuries-old witch and unlike Suspiria, Inferno received a very limited theatrical release and the film was unable to match the box-office success of its predecessor.
While it has its moments, Inferno, imo, tends to be play it weaker than Suspiria, right down to the
fire at the end. Fortunately, for Argento, his next film would leave the supernatural behind, and bring him back to the sub--genre that made him famous.