Jan-Ole Gerster’s Islands is like a horror movie on ketamine

“It’s a ketamine version of a horror film,” says Stacy Martin. “It’s really slow but unsettling.” The 35-year-old French-English actor is describing Islands, an existential noir-thriller about holidayers unravelling in paradise. There’s no violence or jump scares. Instead, the unease co-exists with the glorious landscapes and beaches of Fuerteventura. “It’s like you’re following this river that’s so enticing, but you don’t know when the precipice is going to come,” she says. “And you know it’s coming.”

Directed and co-written by the German filmmaker Jan-Ole Gerster, Islands is like a modern-day L’Avventura with Martin in the Monica Vitti role. At a holiday resort on the Canary Islands, Tom (Sam Riley) is a hard-partying tennis coach whose lessons with tourists are juggled with one-night stands, hard drugs, and hungover stares into the sunny abyss. His attention is drawn to Anne (Martin), a TV actor who’s flown over with her husband, Dave (Jack Farthing), and their seven-year-old son, Anton. A love triangle ensues: imagine Challengers but if everyone’s too depressed to fight, play tennis, or hop into bed for anything other than sleep.

When Dave vanishes overnight, Tom assists Anne on a manhunt that reveals contradictions within her version of events. Anne, whose hair is dyed like a Hitchcock blonde, hints that she met Tom at the resort around a year before Anton was born; with Dave’s drunken confession that he might be infertile, Tom feels compelled to protect Anne amidst suspicions of murder. 38 acting credits into her career, Martin has never played a femme fatale before like Anne.

“She’s at a different stage in her life than I am,” says Martin over a Zoom call in early September. “She’s at a point where things could either completely combust or resolve themselves. I liked playing someone who’s maybe making the wrong decisions in a messy situation. As a human being, I’m pretty boring, and I like to know when things happen. I’m always on time, if not too early. But she’s impulsive and unafraid.” Is it harder playing someone unlike yourself? “It’s so much easier, because you know where not to go.”

Providing long, thoughtful answers to each question, Martin is speaking to me a few days after she was in Venice for the world premiere of Mona Fastvold’s arthouse musical The Testament of Ann Lee. A year earlier, she was in Venice for Brady Corbet’s The Brutalist. A glance at the London-based actor’s filmography reveals her versatility: none of these projects are alike, nor are they similar to her best-known roles of the past. While Martin is coy about what she’s most recognised for, it’s presumably her outstanding onsceen debut in 2013 as the lead of Lars von Trier’s Nymphomaniac.

“I’m finishing up Sense and Sensibility with Georgia Oakley,” says Martin. “With all the work I’ve done, I hope people can see that I can do as many different things as I can. I’d be bored playing the same role all the time. I like challenging myself. The adrenaline is part of what keeps you going.”

Between the ages of seven and 13, Martin lived in Japan without learning the language. Before then, she grew up in Paris. I ask about how Anne’s displacement is enhanced by her inability to communicate with the Spanish-speaking locals. “Because I know French, I had to pretend I didn’t understand more than Anne,” says Martin. “When you’re building a story, language is so interesting because it informs our behaviour. That distance of language is also a distance of mentality and psyches.”

With my characters, I know who they are once I find their costume

Oblivious to the locals gossiping about her in Spanish, Anne responds to the potential death of her husband with sunbathing sessions. Anne, to the viewer, is an enigma whose sunglasses offer protection from more than UV rays. “The whole mystery of the movie is that you’re never sure,” says Martin. “You have to find the balance between giving too much away, and not giving too much away.”

To achieve that balance, did she study Michelangelo Antonioni? “I watched a lot of that. But the most surprising element of preparation was arriving in the Canary Islands. Fuerteventura is such a strange, arid island. It has lots of tourism. It makes you look at nature and humanity, and what we’re doing to it. It was a strange mirror. The best part of acting is when you don’t realise that you’re acting.”

Martin recently wrapped on The Queen of Fashion, an Isabella Blow biopic in which she plays the model Daphne Guinness. Martin, too, is a sort of queen of fashion. She fronted Miu Miu’s first-ever fragrance campaign and wore Louis Vuitton on the red carpet for The Testament Of Ann Lee. “Having worked with Mrs Prada and now Nicolas Ghesquière at Vuitton, I see how they translate the way they view the world through clothes. It’s such an art. You wear their clothes and incorporate them. It becomes another form of collaboration. With my characters, I know who they are once I find their costume.”

Also on Martin’s CV is Stanley Schtinter’s 2024 film Schneewittchen, in which she played Snow White. Except it’s not on the literal CV on her agency’s website, and its Letterboxd page vanished shortly after a 35mm print was screened at the BFI. (On the Wayback Machine, the top Letterboxd review goes: “This just pissed me off.”) Martin explains, “It’s an unconventional film in the sense that Stanley didn’t seek to put it in cinemas, or give it to a streamer. It was about the experience of seeing it, almost like a play, where you go and see it, and when it’s done, it’s done.”

Martin, then, is keen on collaborating with rule-breaking directors, which explains why she’s acted in all three of Brady Corbert’s films, all of which were co-written by Mona Fastvold. “Every frame in Brady’s films is so thought through, but, in terms of acting, he’s a very hands-off director who trusts that the actors will get to the point he wants,” says Martin. “The Testament Of Ann Lee was even more choreographed in the sense that there’s dancing, music, and singing. But the amalgamation of talented, creative people who are able to collaborate is when magic can happen. I saw it for the first time at Venice. It’s wonderful.”

Martin reiterates her own punctuality and commitment when it comes to movie sets, even if the films themselves break conventions. “I like being chaotic within the constraints that I’m given,” she says. “You can do work that that will ask questions philosophically, politically, and socially, without having to turn up late, without having to spit on people. I like being a rebel with the choices that I make, and not with the actions that I do.”

Islands is out in UK cinemas on September 12.