You’re an 18-year-old school leaver, working in a florist’s and all set for a stint volunteering in Africa, when your godmother asks if you’d like to appear in a film. As its star. In 10 days’ time. For most of us, it would be the stuff of fairytales or fever dreams, but for Honor Swinton Byrne it was real. There would be no need to learn a script, she was assured, because it was all going to be improvised. All she needed to know was that she would play a film student called Julie, a lightly fictionalised version of her godmother, Joanna Hogg, who was also the film’s auteur-director. “From what I understand, she couldn’t find Julie in these posey professional actresses who were very comfortable in front of a camera. She just said they’re all too pretty. And then she cast me. Which, you know, I took as a compliment,” says Swinton Byrne. She lets out a throaty laugh, wriggles her feet out of a pair of sparkly stilettos and snuggles herself more comfortably into a sofa at the upmarket central London hotel that is the base for her first solo publicity round, for the sequel to that first film. The Souvenir was one of the critical hits of 2019, which won the grand jury prize at the Sundance festival and went on to be named film of the year in a poll of 100 critics around the world by the magazine Sight & Sound. Set in the early 1980s, it told the story of a love affair between film student Julie and a charismatic heroin addict, several years her senior, who may or may not work for the Foreign Office. By the end of the film, the mysterious Anthony, a stunning performance from Tom Burke, is dead. The Souvenir Part II picks up the story, as a heartbroken Julie struggles to get her film studies back on track while trying to piece together who Anthony really was. With full makeup and long blond hair lacquered into a tight bun, Swinton Byrne is nothing like the diffident Julie, who drifts through the films beneath a waif-like brunette bob. In person, she is bubbly and unguarded, making no bones about the fact that her shoes pinch and hairpins are scratching her scalp. She’s in London for the film’s gala screening at the London film festival, having just flown down from Edinburgh, where she is in the third year of a psychology degree. It’s the morning after her 24th birthday, which she celebrated with a small group of close friends. “My boyfriend made me the worst cake. He’d never baked before. I kind of want to show it to you,” she says, whipping out her phone to reveal a picture of the cake, which is topped off with a dachshund outlined in wobbly icing. “I love sausage dogs, you see.” It’s no surprise to find that Swinton Byrne loves dogs – she grew up with a houseful of spaniels in the Highlands, three of which were responsible for the first award won by The Souvenir Part II, in Cannes last summer: the Palme Dog, for the year’s best canine performance. Rosy, Dora and Snowbear follow Julie’s mother, Rosalind, around their large family home in the film with a bum-waggy devotion that clearly goes beyond method acting. And that’s because Rosalind is played by the actor’s mother, Tilda Swinton, who glides quietly through the films with her dogs, in a dowdy, Thatcher-era perm and home counties tweeds. The relationship between mother and daughter has its own trajectory, which rings with authenticity. In the first part, Julie wobbles on an adolescent tightrope between neediness and resentment: she lives in a Knightsbridge flat provided by her indulgent parents and is forever touching them for money, while spurning their values and advice. By the start of the second part, in the aftermath of Anthony’s death, Julie has retreated to the family home. When she storms away in distress from the perfectly set dinner table, her mother crouches outside the bathroom, listening to her daughter vomiting into the loo, before tiptoeing off again without saying a word. By the film’s end, they have found their way to the sort of mature friendship that can only come when, in the terms of a psychology student such as Swinton Byrne, a child has truly separated. It’s a perceptive picture of a particular sort of upper-class English family, which Swinton Byrne points out is a generation removed from her own. So how relatable was it to her own childhood, growing up with her twin, Xavier, in a later, more bohemian, manifestation of the haute bourgeoisie? “It really could not be more different,” she says. “My mum and I are best friends and soulmates, we have the same mannerisms. Rosalind and Julie aren’t touchy feely and all over each other like we are. Trying not to curl up on her knee or make a joke about something felt really unnatural, but it was also a real laugh.” Swinton broke up with the twins’ father, the playwright and artist John Byrne, when Honor and Xavier were small, though they continued to co-parent. For the first years of their life, says Swinton Byrne, they went wherever their mum happened to be working. “We started school very late because we didn’t leave her side until we were seven or eight.” When they finally knuckled down, it was at a Steiner school near their home that had no truck with conventional education. “And I loved it, because I learned such practical skills. I make all my birthday and Christmas presents for everybody. I really enjoy whittling stuff out of wood,” she says. The only problem was that it had no secondary section, so Swinton teamed up with a group of other like-minded parents to set up their own school. A newspaper report, when the twins were 14 years old, depicted a rural idyll, with the children setting off for a weekend fending for themselves on a remote island with canoes they had made themselves. Though the tone was admiring, the article mildly questioned what would happen to the students afterwards, without any exam results to take with them into the world. The answer, says Swinton Byrne, was that she got into university on a 10,000-word essay, having graduated from school via a Ted talk-style taped interview. At first, she thought she wanted to be a doctor and was aiming for an access-to-medicine course, “but I’m such a big hippy that I believe in things just happening and decided to go to Africa instead”. She landed a volunteer teaching job in Namibia, but wasn’t so much of a hippy as to neglect earning the money that would get her there, hence the florist’s job, which involved taking flowers to weddings all over the Highlands. Then along came The Souvenir. Discounting a handful of school plays, it was her first acting role, she says, but it was not her first appearance on film. In 2009, she made a blink-and-you’ll-miss-it debut in I Am Love, a lush feature about a woman’s attempts to escape from her husband’s rich and restrictive Italian family, which Swinton starred in and co-produced with its writer/director, Luca Guadagnino. Her little face flashed up in a single shot, upside down, as a hallucination of her distraught mother’s prepubescent self. As teenagers, in 2015, she and Xavier appeared as themselves, in a 25-minute documentary that Swinton made as part of a four-part tribute to a family friend, the art critic John Berger. The Seasons in Quincy gives a glimpse into an apparently idyllic childhood in which her mother’s work and their family life appear to flow seamlessly into each other. The twins are shown packing eggs from the hens at their Scottish home to carry by train across Europe to Berger’s home in the Haute-Savoie, where he lectures them on the continuity of rural life and sends them off into the countryside to sample walnuts and raspberries and make candles with his son, Yves. Honor is clearly the more relaxed of the siblings, with an innate ability to say more by doing less, allowing the film’s mood of loving curiosity to play across her face as she listens to Berger, while quietly sketching his portrait. It’s the same quality that she brings to Julie in The Souvenir and it’s in marked contrast to the animated young woman in front of me, whose features are constantly on the move. The two Souvenir films have taken the family business to a new level, involving her in recreating the intimate life of her own godmother. Hogg and Swinton first met as small girls, but became best friends after the wannabe director cast the wannabe actor in one of her National Film School films, The Rehearsal. How did it feel to be trusted with such a raw, unformed part of someone she had always known as an adult? “It was really moving,” Swinton Byrne says. “I’m an unbelievably emotional person, which is why I study psychology. I just can’t ever get sick of talking about feelings. I think there’s such strength in vulnerability and I was so moved to be given the opportunity to speak with Joanna about experiences that were very different from mine but in some ways also quite similar.” In particular, Julie’s passivity in the face of a boyfriend who lies to her and steals her things was initially hard for a 21st-century feminist to take, Swinton Byrne admits. During filming for the first part, she questioned Hogg about why she didn’t walk out, convinced that she would never behave like that herself. The memory makes her laugh: “I was 18 and I hadn’t had any adult relationships.” The toxicity of the relationship between Julie and Anthony only became clear anyway during the seven weeks of filming. “Tom [Burke] had read the manuscripts. He was privy to the information that he was going to be an addict and he was going to die, but I knew nothing,” she says. “So when my mum told me, in the film, that Anthony was dead, I was extremely upset, because I really had no idea.” The idea that her mother, her godmother and her co-star could have colluded to keep her in the dark seems so bizarre that I wonder if I have heard her right. But she insists it’s true: the first she knew of this fatal plot twist was when the news was broken to Julie on screen. Part of the pleasure of watching the second film is to witness art mirroring life: though Swinton Byrne is still six years younger than Julie at its end, she has done her own growing up both on and off screen. “I’ve had relationships which I look back on and think, why didn’t you leave? You can’t explain it. I had a boyfriend who took a lot of cocaine and I had no idea at the time. And I don’t even drink, I’m really not into all that stuff.” And then there was the teaching she did between the two films in a remote area of Namibia. “I like to think that I grew some balls and came back an adult.” Whereas in Part I, both actor and character had to live with not knowing what was going on, by the end of Part II, they have taken control. When Julie directs her graduate film, Swinton Byrne is getting her own first taste of directing. This includes facing down the scepticism of her film school examiners about her decision to ditch a worthy documentary about Sunderland for something altogether wilder and more adventurous. “By the end of that scene I was so angry,” she says, “but you only see the tail end of it.” The film within a film is presented as she directed it. “I think the tape we did was about 45 seconds long. It’s just trial and error and I don’t know what the hell I’m doing but I’m really really enjoying doing it, finding a rhythm and trying to get my thoughts out through words and then being, like, ‘no actually, I’m changing my mind’. It was difficult but it was so much fun.” The question of whether this actually represents some sort of directing debut hangs in the air. It has certainly given her an appetite for making a film of her own one day, she says, but in the meantime there’s her degree to complete, which is particularly hard because she’s never had to sit exams before. She’s resolutely not part of the university theatre scene and does not intend to go on to do any training. “I’m not interested in learning how to act, apart from through acting,” she says. “I feel like it would cloud the joy I find in it.” This doesn’t come across as arrogance but a refreshing form of confidence: she simply doesn’t relate to the need to prove herself. It helps that her parents have always emphasised they’d support her in anything she wanted to do. “My mum has made it very clear that if I wanted to be a bin man, she’d be happy,” she says. At university, which she started a fortnight after finishing The Souvenir Part II, she moonlights as a waitress and was astonished when a customer, to whom she had just served tomato soup, recognised her through her Covid mask; her boyfriend isn’t a student but a club footballer, who also works as a bartender. One day, she says, she had to miss a day’s classes for an awards ceremony. “I said I really need to go to this thing and one of my friends said, ‘Are you catering staff?’ And I was like, no I’m actually, like, going because I’ve been nominated for something. There was about two minutes of them being ‘oh that’s so cool’. And then we talked about something else.” She hopes to do more film work after graduating this summer, but she is also interested in psychotherapy and would like to do some more teaching one day – “there are so many things I want to do”. There’s a line in Souvenir II about the importance of avoiding the pressure to be obvious. What does that mean to her? She starts twiddling with her bun and suddenly seems very young and unlacquered. “Oh God,” she says, “I was really hoping no one was going to ask me that, because I ought to have a really great answer and all I can say is that I think it means don’t be a sheep. Think outside the box. But isn’t it ironic that I’m using a cliche to talk about cliche?” She gives another throaty laugh, slips her feet back into her pinchy stilettos and collects herself up for her next interview. She might not have the answer, but she fluffs around it with such sweetness and wit that it would make a pretty good calling card for a role in an improvised comedy.