Half an hour into Anemone, Daniel Day-Lewis, arguably the world’s greatest living actor, delivers a 10-minute monologue about consuming Guinness, curry, and laxatives in order to vengefully shit into a priest’s mouth. It’s hard to imagine anyone else executing such an odd, challenging speech, or indeed anyone else convincing him to do it: it was directed by the actor’s son, Ronan Day-Lewis. A first-time filmmaker who co-wrote Anemone with his father, the 27-year-old New Yorker can’t be accused of following a screenwriting template, even if his path into the industry is arguably the most typical.

Turning up early to our interview during the London Film Festival, Ronan Day-Lewis is open and frank about his fortune as a filmmaker. “It’s obviously nepotism,” says the amiable, Irish-born director. “Anyone is incredibly lucky to be able to make a film, and I’m hyper-aware of how lucky I am to do this with him.”

After Phantom Thread wrapped in 2017, Day-Lewis’s father announced his retirement from acting. Did Ronan see it as a public service to get Daniel out of retirement? “It was a unique position to work with him on something very casually in a low-stakes way, in a domestic environment, over a long period of time,” says the younger Day-Lewis. “If not for that, maybe he wouldn’t have found his way back to work that way.”

Framing landscapes as if they were watercolours, Anemone finds beauty and loneliness in its rural, English setting. In an isolated cabin, Ray (Day-Lewis) is startled by the arrival of his brother, Jem (Sean Bean), a reunion that prompts the aforementioned “I squatted down and I manured him” monologue and an impromptu dance party. It’s the 1990s, before everyone was easily traceable, and two decades earlier, Ray abandoned his family: he was a soldier involved in the Troubles. When the two moody men aren’t fighting and drinking, the film cuts to Jem’s wife, Nessa (Samantha Morton), and her son, Brian (Samuel Bottomley). What unites the strands are fantastical incidents, like an apocalyptic ice storm.

Ronan Day-Lewis isn’t just the son of a three-time Oscar-winning actor. His mother is Rebecca Miller, the director of Maggie’s Plan and Apple’s recent Mr Scorsese documentary (Ronan is credited as a camera operator), and his grandfather was the playwright Arthur Miller. At the age of seven, he visited the set of There Will Be Blood, an experience he refers to as life-changing: it was the first time he’d seen his father act, and it was with Paul Thomas Anderson, a director he’d later idolise.

One reason cited by Day-Lewis’s father for retiring is the hassle of promoting a movie. How is Day-Lewis – a non-performer who doesn’t appear in his own film – finding being thrust into the spotlight? “I think I’m a pretty shy person,” he says. “My background is more in painting, which is super-solitary, and just you in a room with a thing on the wall. It’s been an adjustment. It’s been intense. But it’s cool meeting people, and it forces you to think more deeply about what you just did, which is maybe not a bad thing.”

I’m a pretty shy person. My background is more in painting, which is super-solitary, and just you in a room with a thing on the wall. It’s been an adjustment. It’s been intense

Graduating with a BA in Art from Yale in 2020, Day-Lewis is a painter whose work was presented in 2022 at Sotheby’s New York as part of a Jerry Gogosian-curated sale. Two of those paintings, Don’t Look Now and It’s Okay to Eat Fish Cause They Don’t Have Any Feelings, feature a sci-fi animal that cameos in Anemone. (It’s translucent, like a giraffe-necked dog that’s turned into a giant tooth, and has a dangling penis.) To accompany the film, Day-Lewis has a solo exhibition in LA called – it’s just as difficult to pronounce – Anemoia.

“It’s such a big leap to make your first feature, and there’s so much that’s intimidating, like leading a crew, and deluding yourself into thinking you can do that,” says Day-Lewis. “It helped me to think of filmmaking as an extension of what I was already doing in painting. I’m trying to think of them as two expressions of the same impulse.”

The obvious example is the mysterious creature from his paintings. Day-Lewis struggles to explain its existence in both his film and prior artwork, including as a massive sculpture: the point is that it can’t be summed up in words. “My dad had been wondering if the creature should appear somewhere, because he was very familiar with it from my paintings. The metaphysical aspects of the film opened a portal for things like that to happen. These moments feel like X-rays into Ray’s psychological space.”

When Day-Lewis paints, he listens to non-stop music, especially artists like Slowdive. During the writing of Anemone, it was him, not his father, who compiled the playlists. The script had specific songs written into it, like Kurt Cobain’s cover of “And I Love Her” (“it was impossible to get”) and Cluster & Eno’s “Steinsame”. The final film’s score by Bobby Krlic is hugely indebted to shoegaze: on multiple occasions, swirling guitars build and build until there’s a hard cut to a silent room.

As a teenager, Day-Lewis watched YouTube videos about the mechanics of screenwriting. He’s now written a number of scripts, including a few on his own. With his father, they only wrote Anemone when they were in the same room together, usually at the kitchen table. It was done without an outline. “We were disregarding so many of the screenwriting rules you learn. It gave it a bit of a punk spirit.”

He points to the Guinness-shitting monologue as a key example. His father improvised it as a lengthy block of text while he transcribed it. “It’s unusual to have, like, no dialogue for the first act, and then to have that much dialogue to shepherd you into the rest of the film,” he says. “It felt like a point of no return. It gave us freedom.”

Day-Lewis is clearly political – his Instagram bio is two words: “Free Palestine” – but he doesn’t want his films to be didactic. To sum himself up, he says, “I want to keep letting myself be drawn to images, themes, feelings, and worlds I want to step into.” The director has a solo script that he feels “strongly” about, and hopes will be his next film. However, he notes, “My dad and I, if we can find something else we can get equally obsessed with again, I think we’d love to do it together. We’ve started bouncing some ideas around.”

Anemone is out in UK cinemas on November 7