Leanne is first in line on Saturday, standing outside the 19th-century Memorial Uniting Church in Hobart, Tasmania. She’s been waiting in the winter cold since 4.45am, but has no idea what for: “It’s a film?”

The film is Sculpt: Eye of the Duck, starring Willem Dafoe and Charlotte Rampling – and only one person gets to watch it at a time. Its director, the French conceptual artist Loris Gréaud, has cut six versions since its 2016 premier at the Los Angeles County Museum of Art; less than 500 people saw that first film at Lacma and even fewer have seen the subsequent edits, although you can dig up some clips on the dark web. Dark Mofo – Hobart’s winter festival – is now screening its seventh iteration, with nine tickets made available each day. Only 90 people will get a chance to watch the movie, and the act of seeing it is part of the show.

I wait at a red park bench. A silent, black-suited driver steps out of a black BMW. He hands me a metal military dog tag engraved with the film’s title, and a red business card: “Please fasten your seatbelt,” it reads. “For your safety this car is fitted with a camera.”

The film – which we’ll get to – is set within a type of stock market trading in “moments” of pure emotion and raw intensity; moments made valuable by their unattainability. My car snakes between Queens Domain’s bare trees as, over the speakers, Dafoe’s voice recounts a murder we can assume will be part of the plot. There’s a synergy with Dark Mofo itself, a festival that often trades in trials of the flesh and one-off experiences – and the film, and its unattainability, is designed as both a product and subversion of art world consumer capitalism.

A phone starts ringing on the passenger seat; I answer it, but the voice is too faint to hear. The movie’s world is merging with my own and the mind games have begun.

My car pulls up to the Playhouse Theatre. A severe-looking porter peering through the red drapes inspects my dog tag. Entry is granted to the almost pitch black empty theatre. Its chairs are piled up in a chaos of upholstery. The bellhop pours me a viscous cocktail garnished with secretions from a glass eye dropper. I take my spotlit red velvet seat and the film begins.

Even having read the synopsis, the art market plot is essentially inscrutable. Instead, we’re offered a montage of surreal decadence that’s exquisitely, bizarrely, distressingly beautiful and disorienting in equal measure. What unfolds on screen goes beyond a fever dream; it’s more like a telepathic inferno extending beyond the screen’s frame, with Gréaud the arsonist combusting my psyche.

Dafoe’s character cackles with sadistic wonder at women held aloft in a shibari ritual. The Japanese erotic knot tying tradition is a trust exercise, but the scene depicts something that feels cruel and dangerous. “The marriage of reason and nightmares gives birth to a world that’s even more ambiguous,” mutters Charlotte Rampling, dressed in a ghostly “grumpy bear” costume, barely audible over the soundtrack.

A voodoo priestess places an incantation on 16mm film rolls, which were later used in the making of more of the film. An old man deposits fly larvae on film strips with an eye dropper that makes me question my cocktail’s ingredients. Describing this movie feels like tearing strips from a precious tapestry.

When it ends, the exit is lit up by a spotlight. I walk into the street discombobulated, and a woman places a USB drive into my hand. I turn in circles, stupefied and unsure if the experience has finished. I follow the USB courier down an lane-way; she sees me, doubles back and scurries through the Playhouse’s green stage door. I ring the bell and wait. The expressionless porter opens the door, stares at me, then closes it in my face. I suspect I’ve gone rogue here; they didn’t expect me to chase the performer.

The day before my screening, I spoke to Gréaud, who explained that the film explored “a dichotomy between fiction and reality and how to make things from fiction crash into reality.” The two, he believes, are indistinguishable and we need a new word: “Real-iction”. He tells me about the unlocked New Orleans voodoo temple in which that spell was placed on his film stock; about how $100 notes protruding from the walls were left untouched by the neighbourhood’s resident drug addicts, seemingly through some mystical protection. He’s a true believer in the spirit world: “I can’t talk about it because it brings some bad luck each time. It’s not a superstition. I experienced something with my older brother and little sister.”

Gréaud was unwell on the day of our interview, and left to get a CT scan before his flight. But the next day, at my screening, I watched a man who could be a younger Gréaud undergo his own CT scan. Was the artist’s alleged appointment yet another layer in Gréaud’s “real-iction”? Leanne, first in line on Saturday, also found herself questioning when the experience began or ended; after her screening, she tells me about her own BMW ride – and the man who tried to get into the car with her. She thought it was part of the performance, but it was just a wasted bloke still up from the night before.

“I felt like I had been wrung out,” Leanne says. “As a woman, being picked up by a stranger and being driven around then being placed in a cinema by yourself – it made you feel like you were handing over control, very vulnerable. I felt like I was being watched the whole time.” Still, she says, her experience was positive.

After the screening, later that night, my phone rings and it’s a pre-recorded voice of Dafoe: “It’s time to open the window, let the wind carry me away. I will be a disciplined speck of dust.” The hotel window doesn’t open and the mysterious USB stick is staring back at me from its zip-lock bag. What it contains is just for me.

• Sculpt: Eye of the Duck is screening 17-21 June in Hobart, with tickets on sale daily from 9am. Nick Buckley travelled to Hobart as a guest of Dark Mofo