For all her mastery of horror, author Shirley Jackson had a flair for arch humour that bordered on the camp. Her slender 1962 page-turner ‘We Have Always Lived in the Castle’ ends on an exchange between the Blackwood sisters that shows a deep irreverence for the macabre events that came before, and leaves the reader smiling ruefully.

There are similar tonal values to Josephine Decker’s Shirley, an adaptation of Susan Scarf Merrell’s semi-fictional novel of the same name. Elisabeth Moss channels a ghoulish pantomime energy in the title role that, from an actress of her subtlety and breadth, is a deliberate creative choice. Shirley is not so much about the writer Shirley Jackson as it is a concocted psychodrama infused by the qualities of her work, where the real and the imagined co-exist in queasy disharmony, and women escape male dominance through use of an invented secret language.

Shirley Jackson died in her sleep in 1965 at the age of 48, having spent the final 20 years of her life in North Bennington, Vermont, with her disloyal husband Stanley Hyman. A literary critic for The New Yorker, by this point he worked as a lecturer at Bennington College while the increasingly agoraphobic Shirley stayed home wrestling her stories onto the page. Shirley is set during the time that our antiheroine is working on an idea that would become the 1951 novel ‘Hangsaman’, loosely based on the disappearance of college student Paula Jean Welder.

Paula may have been real, but Rose (Odessa Young) and Fred Nemser (Logan Lerman) are fictional entry points to the cloistered domestic world that Shirley and Stanley (Michael Stuhlbarg) inhabit. The film opens on the fresh-faced young couple sitting on a train to Bennington. Rose is reading Jackson’s ‘The Lottery’ in The New Yorker – a short story that yielded record-breaking amounts of reader feedback, much of it hate mail. Rose, however, is so aroused that she seduces Fred to the bathroom for a quickie. Afterwards she looks at herself in mirrored surfaces. Decker cuts together shots by DoP Sturla Brandth Grøvlen in such a way that reflections and reality blend, setting the tone for what is to come.

Decker’s fourth feature is her first without regular DoP Ashley Connor and her first directing a script written by someone other than herself, in this case Sarah Gubbins (I Love Dick). The result is a fusion of styles that does not always cohere. With previous features Butter on the Latch, Thou Wast Mild and Lovely and Madeline’s Madeline, Decker developed a trademark technique of telling female-led stories by plunging into the senses and sidelining narratives by centring the chaotic intensity of feeling alive.

Shirley has a more conventional script, replete with sparkling lines of dialogue, yet Decker’s taste for undoing the seams of characterisation shows up in the film’s visual language, as the frenetic, handheld camera is thrown at the subjects as if trying to get under their skin. This is a film trying to wriggle out of the straitjacket of its own story, the better to reveal the symbiotic passions within its two leading ladies.

When Rose and Fred arrive at the Bennington house, there is a party in full swing. Stanley is out front playing master of ceremonies. Shirley festers in an armchair inside, surrounded by acolytes hanging on her every poisonous word. The Nemsers are supposed to stay for only a short spell, as Fred settles into his new post at the college, but it doesn’t turn out that way. Stanley cajoles Rose into taking on the role of the housekeeper so she spends her days cooped up in the house with Shirley, while the men are on campus all day and sometimes all night.

Shirley cuts through the hero worship coming from her ingenue houseguest with such brutality that Rose tells Fred: “She’s a fucking monster.” Pedestal out of the way, up springs an intimate dynamic. Rose cooks, cleans, assists. She starts as a nanny, evolves into a friend and then it’s a short leap into something more creatively and erotically inspiring. Their conversations become Shirley’s drafts, narrated by Moss, who envisages her newest creation with Rose’s face. Metafictional nods to Jackson’s most famous stories are everywhere, and as her fiction was informed by details of her life, the result is an ever-narrowing spiral of themes: a succession of Russian Dolls full of lost girls, banal oppressors and magical witchcraft.

Moss leans into teeth acting, snarling and smiling with gentle delirium. Her lack of make-up, lank hair and tendency to hide in bed in a white nightdress contrasts with Rose who looks every inch the fragrant faculty wife. Young injects this doll-like avatar with such vulnerability and curiosity that she is the revelation. Her character is a foil, there to bear witness to the force of nature that is Shirley’s domestic life, yet she emerges on her own terms as the lost girl at the centre of it all.

If Rose is Shirley’s protagonist then Stanley is her antagonist. He is abominable one moment, charismatic the next. Michael Stuhlbarg’s performance is ever shifting. He is an energetic, nimble Rumpelstiltskin, waiting for his wife to spin gold, patronising her like a precocious child. She has the talent. He has the social freedom. They have an arrangement whereby he is allowed affairs. Neither is interested in leaving or improving their toxic partnership. It is presented as inevitable. “Let’s pray for a boy,” Shirley whispers to Rose about her unborn child. “The world is too cruel for girls.”

The residual impression is that these women are trapped and there’s nothing in their supernatural understanding that changes this. The chord Decker plucks with Shirley is from the interior world, where women’s wild energies have the room to play out in full. It’s the same place from which fiction flows, and the thwarted can have their day to do with whatever they will. Decker shows us the real cage and she shows us the imaginary freedom – a sanctuary that is weighted with more importance than any real-life devastation. As Shirley Jackson wrote in one of her journals: “Writing is the way out.”

Shirley is released 30 October. Read more in LWLies 86: The Shirley issue.