After the release this year of Ammonite, with Kate Winslet and Saoirse Ronan as 19th-century fossil hunters who fall in love in inclement weather, Saturday Night Live ran a trailer featuring Carey Mulligan in a spoof version. A sombre voice heralded “two straight actresses who dare not to wear makeup” along with “Academy award-winning glance choreography … the world’s saddest flirting … and best supporting actress nominee the wind.” After promising that the stars would “round all the bases, like grazing fingers, washing carrots”, the voiceover announced: “Lesbian Period Drama. You get one a year. Make the most of it.” Not this year you don’t. The World to Come depicts a same-sex relationship flowering in the harsh conditions of the US frontier in 1846, where timid Abigail (Katherine Waterston) and brash, flame-haired Tallie (Vanessa Kirby) drift away from their husbands (Casey Affleck and Christopher Abbott) and into each other’s arms. The glancing is plentiful, the flirting desperately sad, the wind howling as if vocalising the women’s anguish. There is finger-grazing, but no carrot-washing, although the sweethearts do get to pluck a chicken together. “Badly!” Kirby points out when she joins Waterston and me for this interview at the Corinthia hotel in central London. The women, who became friends while making the film in 2019, are thrilled to see each other; in her excitement, Waterston dives into the minibar and grabs a snack before gasping at her audacity. “I’m acting like I’m on some big-budget press tour. It’s insane that I just did that.” Kirby chips in: “Let’s order the lobster!” Having arrived before her co-star, Waterston had ordered mint tea and coffee on Kirby’s behalf. “I didn’t know if you’d be needing a comedown or a pick-me-up, so I got your one of each,” she says, curling her legs beneath her in an armchair. Seated on the sofa opposite, Kirby tilts her head appreciatively. “You’re enough of a pick-me-up,” she says. Both women live in London – Kirby was born and raised in the city, while Waterston was born there but raised in Connecticut – and have been meeting up whenever work and lockdown have allowed. Both have also been busy. Kirby, 33, who was Oscar-nominated this year for her performance as a grieving mother in Pieces of a Woman but is best known as Princess Margaret in The Crown, is shooting the next two instalments of Mission: Impossible back to back. Meanwhile, Waterston, the 41-year-old star of Alien: Covenant and Inherent Vice, has been filming the third Fantastic Beasts movie. It was while Waterston, the daughter of the actor Sam Waterston, was here from the US in 2018 to make the second one that she decided to stay. “Well, there was Trump back home. Although here, of course, there’s …” Her expression is that of someone who sold her place in the frying pan to make a home in the fire. Waterston had admired Kirby from afar before they arrived in Romania to make The World to Come. What was she a fan of? “Her courage. That little thing,” she says. “A lot of people go small because they’re so afraid of striking the wrong note, but Vanessa doesn’t do that. She can’t bullshit.” Kirby is squirming, but Waterston stands her ground: “It’s what I think!” “I always feel like the pantomime ham,” Kirby says. “Restraint has taken me such a long time to learn.” She well remembers the shock of going from the vast Olivier stage at the National Theatre in Women Beware Women in 2010 to her first TV appearance, opposite Ben Whishaw in The Hour. “All that projecting reads so fake when there’s a camera in front of your nose. Then I went through a stage of doing nothing. One comment was: ‘She’s dead behind the eyes.’ That was the review.” She has always been curious about other actors’ processes. When she was working with John Hurt on the holy grail TV drama Labyrinth, he told her he didn’t believe in method acting. “He said: ‘The audience won’t know if you’re thinking about your Tesco shopping.’” But Kirby had already experienced what she now knows to be the giddy rush of fully immersive acting when she was a teenager at school, playing Gertrude in an all-female production of Hamlet. Backstage, between scenes, she found herself thinking in character. “I was having a panic attack about what I was going to tell Claudius,” she recalls. “And when I came off stage at the end, I was like: ‘Ohhh. That was acting.’ It’s not what happens on stage in a big booming voice; it’s that bit in the corridor.” Waterston has a suggestion. “That could be your old-lady autobiography,” she says. “Acting in the Corridor: Memories from Stage and Screen by Vanessa Kirby.” They collapse into giggles. While Kirby has her own process, she is open to learning. “Working with Katherine was an education,” she says. Waterston groans – “Oh, please!” – before dropping to her hands and knees and crawling behind the armchair to hide. Kirby presses on: “She’s forensic and she doesn’t leave anything unturned. She has to know psychologically why she’s doing the slightest thing, whereas with certain bits I’ll just suspend my disbelief.” Confident that the praise is ebbing, Waterston returns to her seat. “I suppose it’s greed, in a way,” she says. “I don’t want to miss anything that could be part of telling the story.” Immersion in The World to Come was helped by the location: cast and crew were holed up together in a no-frills mountain lodge. “It was the middle of nowhere,” Kirby recalls. “No cars, just horses and carts. We were shooting in a valley we had to hike to. It helps so much. It’s almost impossible otherwise to truly experience a world without … this.” She picks up her phone, brandishing it like a dirty sock. She was spared too much hard labour – “I was quite relieved when I read the script and saw I didn’t have any chores,” she says – whereas Waterston tills, hoes and milks her way through much of the film. Had the scene in which she administers to her husband an enema of molasses, warm water and lard not taken place off-screen, you can bet she would have rolled up her sleeves and got stuck in. About the milking, she seems especially proud. “I did even more than you see on screen,” she says, eagerly. “Certain shots, I was disappointed that it’s only my hands. I was, like: ‘Will the audience know they’re my hands?’ I’m sure there are actors out there who could skip the milking lessons and still do a good job, but I’m not one of them. All we’re doing is trying not to suck, right?” Their performances are bone-deep and fine-grained, but they weren’t arrived at in a vacuum. Waterston’s acting choices as Abigail, who describes herself in the film as “a pot-bound root”, helped shape Kirby’s own decisions about how to bring Tallie to life. “Being in front of Katherine informed what I did,” she says. “Early on, I thought: ‘Oh, OK. To make this happen, I’ll have to be even more front-footed than I thought, because she’s really not going to come towards me. And this could go on for months!’ I knew she wouldn’t kiss me unless my attitude was: ‘I’m coming for you.’” She looks straight at her co-star. “You gave me permission to be more full-bodied.” The traffic flowed both ways. “What I got from Vanessa when she looked at me was that she saw something in Abigail,” says Waterston. “Some place that existed beyond the pot-bound root. Tallie sees the extent of the person within. That’s a wonderful articulation of what it really is to love someone. There’s something so romantic about it.” Kirby goes so far as to say that the film has changed her. “Making it has been quite profound for me, because I feel more in touch with our female ancestors than I ever have before. Women were literally owned by the men whose land they happened to be on. Think of all those lost voices. For me, the film’s title refers to the world that we’ve inherited from those women who didn’t have the freedom we have.” There is greater sensitivity now about the way women are not only photographed but written about. Lola Kirke took the New Yorker critic Anthony Lane publicly to task in 2018 for describing her clothes in the film Gemini as “unflattering”, while a storm broke out recently when Carey Mulligan challenged the language used about her in a Variety review of Promising Young Woman. Waterston doesn’t read her own press: “When I descend into hell, it will probably be papered with interviews I’ve done,” she says. But she has picked up on these tremors. “There was a certain type of profile, usually in Vanity Fair, that I used to love making fun of. They don’t happen much now: ‘She walks into the room … gamine-like arms, faun-like expression … her hair seems to be hovering a few inches above her shoulder … there’s a smell, yes, a smell like summer rain and ponies …’ And this is a grown woman they’re talking about!” For Kirby, some of the worst offenders have been screenwriters. “Whenever I auditioned for anything, I’d make a note of the descriptions. With female characters, it was always about their appearance. The man would be ‘intelligent, confident’. The woman was ‘blond, every man watches her’.” Waterston agrees: “There were always two categories: ‘We see her and we want to sleep with her,’ or: ‘We see her and we don’t.’” The auditions could be even worse. “I would go along dressed the way I thought the character would dress,” says Waterston. “And then they’d say: ‘If you want the part, come back in a half-length skirt.’ “I was thinking about this when we did The World to Come, because I was trying to understand what it meant to be a pot-bound root who has all this life within. I was thinking back to my early days in showbusiness and what it was to feel like I had this unidentifiable something that I wanted to give, to share, and there just being no playground for that stuff. There was a playground, sure, but it had different rules, a whole different game, even. What makes you pot-bound is when you’re in any situation where you can’t let your roots spread out.” Having said that, she seems full of hope. “I think of the young women today who might previously have been in my position – kind of smart, just wanting to play interesting roles rather than wearing the short skirt and humiliating themselves for 10 years and then maybe getting the second supporting role. It’s so exciting to see what they will get to have, the ones who can now start with the wind at their backs like that.” She glances at Kirby with a gleam in her eye. “We might really be looking at a kick-ass generation.”