Johnson, fresh from the Fifty Shades trilogy – which ended with Fifty Shades Freed earlier this year – takes centre stage in the film, made by Luca Guadagnino and based on Dario Argento’s iconic 1977 horror of the same name.
There are many horrific and unsettling moments of the movie, but it was actually something very different which sent fear into Johnson: the dancing.
“I trained on and off for about a year before we started filming, but I’m not a professional dancer,” she told Entertainment Weekly.
“It was terrifying.”
There’s no grand dance sequence in the 1977 version but Guadagnino explained: “In Dario Argento’s film, you see mostly lessons; there is not a grand dance moment in the movie.
“We felt that dance needed to be part of the process of witchcraft.
“That performance builds towards the greater ritual that is at the core of the film.”
“We were moving on the points of a pentagram, as though the dance were casting a spell,” Johnson explained.
Suspiria also stars Tilda Swinton, Mia Goth and Chloe Grace Moritz, and caused quite the stir when a clip of it was showcased at CinemaCon back in April.
“People at my table turned away from the screen. All I can say is it’s beyond extreme and gross and I need to see more,” one journalist tweeted at the time.
Fandango pointed out that it has “some of the most disturbing body horror”, and another reporter posted: “First clip from Suspiria invokes a dancer being thrown around like a rag doll telekinetically in a mirrored rehearsal space, bones breaking, becoming a contorted mess.
“Very gruesome and hard to watch. This film will make most people feel uneasy.”
Not just in the audience, either: Johnson recently revealed that the filming process left her in need of therapy.
The 28-year-old has bene keeping very busy since the end of the Fifty Shades journey – and will also be seen in The Peanut Butter Falcon and The Translation of Wounds.
The latter sees her teaming up with Armie Hammer and Zadie Beetz, and is a psychological horror film on a fast-track for release next March.
Suspiria is out on November 2.