Joel Coen’s “The Tragedy of Macbeth” is, among other things, visually gripping, a stark, haunting dreamscape that often seems to exist outside of time. While the film is carried by Denzel Washington and Frances McDormand, much has been made — justifiably — of Kathryn Hunter’s eerily limber witch: you can’t look away as she bends and contorts, calling to mind a real-life Smeagol.

But the movie starts with a whiteout, and so we hear Hunter before we see her. It pulls viewers in and reinforces the notion that this nimble performance (she is echoed into all three witches) is not merely a physical marvel or a gimmick. Hunter’s clarity and her agility with her line readings sets the tone — riveting but ominous —for the film.

“When Joel said, ‘We’re not going to see you in the first scene,’ I went, ‘Oh,’” Hunter says, re-creating the sound of disappointment. (Hunter, 64, will be new to most American filmgoers; she’s best-known for appearing in one Harry Potter movie.) “But it’s actually brilliant that you don’t see the witches at first because it makes you think about what is really there and what is not there.”

An esteemed theatrical star in the U.K., Hunter was also grateful for the chance to have audiences focus first on Shakespeare’s words and her delivery of them. “Over the years I’ve been labeled a physical performer and I always say, ‘But what about the words?” Hunter says. “The shape of words is physical too, and the words and physicality must be completely synced up. There is a marriage there.”

After discussing the role with Coen, Hunter would send him short videos of her ideas. “I’d try different positions, I’d be a crow in flight,” she says. (Initially they auditioned women of similar height and flexibility to play the other two witches before deciding to have only Hunter, times three.)

Hunter has been a devoted Shakespearean since reading “King Lear” in school at age 14. A down-to-earth chatty conversationalist, she can also transform an interview into a compelling master class on “Macbeth” and Shakespeare, quoting from numerous plays.

She sees Macbeth’s murderousness as a product of the warrior society, citing Shakespeare’s vivid descriptions of wartime actions as slaughter, not pure heroism and lines like “blood will have blood.” And she notes that “when human beings behave without conscience and awareness,” Shakespeare has nature respond with violence and chaos. “That’s so resonant now.”

She studied at London’s Royal Academy of Dramatic Arts, but her acting was shaped more by devastating injuries suffered in a terrible car accident — a broken back, shattered elbow and crushed foot that had doctors thinking she’d never walk again — and by the resilience she found in the aftermath, as she worked even harder to make her mark.

The accident also taught her about how to use her upper body while the lower half was restricted — as the witch she seems able to contort herself in ways that are not human — a skill she developed further working with the modern theater company Complicité, with whom she has performed for decades. (She also met her husband there.)

The idea of ignoring restrictions appeals to Hunter — years before gender-fluidity became commonplace in theater, she gravitated to male roles in classical plays because they were the more complex and fully developed parts. She has won acclaim as the title character in “King Lear,” “Richard III,” “Timon of Athens” and “Cyrano de Bergerac” as well as Puck in “A Midsummer Night’s Dream” and the Fool in another production of “Lear.” In Coen’s film, she also appears as an old man.

Pandemic permitting, she’s scheduled to star in Eugene Ionesco’s “The Chairs” in the winter, followed by a return to “King Lear” in the spring. She says that the outrage 26 years ago at the idea of a woman playing Lear became a huge distraction and she didn’t feel fully inside the role until near the end. “But I still have the text intact in my head,” Hunter says. “I always wanted to play Lear again so this is a very precious gift.”

While her calendar is filling up, her experience with “Macbeth” made her eager to carve more time for films. “It’s a whole new world,” she says. “You can never get so close on stage and camera allows you to go deep inside a person. It’s amazing.”