Colm Tóibín does not approve of sequels. “It would have been a disaster if Pride and Prejudice had a sequel. It would have been a disaster if Ulysses had a sequel. Imagine!” the Irish novelist exclaims from his study in Columbia University, New York, where he teaches. “It ends with Molly Bloom asleep, then you’d suddenly realise, ‘Oh, my God, it’s starting another day.’” Yet fans of Tóibín’s novel Brooklyn will be delighted to know that after a gap of nearly 15 years he has overcome these misgivings to write a follow-up, Long Island. Set in the 1950s, Brooklyn takes the fairytale of New York – an Irish girl who emigrates to America – and turns it into a heartbreaking story of homesickness and regret (it is a Colm Tóibín novel, after all). Adapted by Nick Hornby in 2015 into an award-winning film starring Saoirse Ronan, it is the best known and loved of Tóibín’s 10 novels. It also has one of the most agonisingly ambiguous endings in contemporary fiction, tweaked for a happy conclusion in the film. “I’ve been with these characters for a long time,” he says. “It’s strange how they don’t leave you.” Long Island returns Eilis, now in her 40s, to Ireland in the 1970s and the possibility of rekindling the romance she left behind all those years ago. While most of the book takes place in Enniscorthy, the small town in County Wexford where Tóibín grew up and where half his novels are set, it opens in Long Island. It is here that Eilis has settled with her husband, Tony, and their two children, until a knock at the door changes everything. Tóibín left Enniscorthy himself in 1975, he says. Following a stint in Spain, he has spent much of his life moving back and forth between Ireland and America, where he now lives permanently. The idea of home – and exile – can be found everywhere in his fiction. “Where did all the Irish go?” Tóibín asked a priest one day when he had been singing in a choir in a Catholic church on 86th Street and noticed that the plaques on the walls had Irish names. “Out to Long Island,” was the reply. “They all went out,” he says. “It was a big dream place for people.” And so Tóibín started taking the train out and exploring the area, following his characters. “I thought I’d be arrested because there was no one walking. I didn’t talk to anybody,” he says. “I wouldn’t write anything. Rule is ‘No notes!’ If you can’t remember it, it’s no use.” This was in 2019, “just before the pandemic and after the cancer”, Tóibín calculates. “I had a window of a year, where I was sort of a free man.” A few months into starting work on his previous novel, The Magician, a fictionalised biography of Thomas Mann which won the Folio prize in 2022, he was diagnosed with prostate cancer. “There’s been no sign of it for five years,” he says now. “I didn’t learn anything from it,” he adds. “If you have to get cancer to learn that life is valuable, and life is fragile, then you really have something wrong with you.” Cancer may not have taught him anything, but it made him stop drinking. “When the chemo was over, I never wanted to taste anything strange, or to have any equilibrium-changing liquid in me again, so I just didn’t,” he says. “And then when I didn’t, I didn’t more.” He loves being able to come home and read or carry on working. “I used to be the loudest and the most crazy. I could go on all night. I don’t do that any more. It’s just great. I’m sorry I didn’t think of it years before.” Tóibín, who is 69 this month, has been reminding us of the fragility of life for more than three decades, in a career that has included being shortlisted for the Booker prize three times (Brooklyn made the longlist), and winning the International Dublin literary award for The Master, about his hero Henry James, in 2006. “This is the first novel I’ve written in which no one dies,” he announces cheerily of Long Island. His father, a teacher, died of a brain aneurysm when Tóibín was 12, the psychic wound from which nearly all his fiction stems. His most personal novel, Nora Webster, published in 2014, is an almost painfully austere portrait of his grieving mother (a published poet) in the years that followed. Each of his novels is a reaction to its predecessor. After living with “the screeching” Mann family and a 20th-century European backdrop for The Magician, he longed to return once more to Enniscorthy for the new book. “It was a relief to be able to go back to those few streets, to go back to that weather, to go back to those sort of subdued colours in the landscape, and subdued responses to things,” he says. “This is much more intimate, it’s a smaller canvas. It’s chamber music. It’s a work with pencil.” Tóibín is as mesmerising in person (even on screen) as he is on the page. He talks about the mechanics of fiction – his own and other writers’ – with an obsessive’s devotion, tracing invisible connections in the air with a pencil. You wouldn’t want to skip a Tóibín seminar. Where Brooklyn was influenced by Henry James’s Washington Square and The Portrait of a Lady (if ever there was a novel demanding a sequel), Long Island takes James’s famously difficult late novel The Golden Bowl as its template – but don’t let that put you off. “It is a maze of knowing, not knowing,” he says of the love triangle at its heart. “Even when they know, they don’t know they know.” Tóibín is a master of silence and shadows; his subjects are abandonment, loss and denial – the things not said, the feelings not acted on. As the final line in Brooklyn puts it: “She closed her eyes and tried to imagine nothing more.” His novels are so quiet you can almost hear the chink of teacups on saucers and the breaking of hearts. In Long Island, he wanted to bring everything “down, down, down”, he says, until his voice is barely a whisper. He spent months reading and rereading the manuscript. “Any time I thought ‘that’s a good sentence’: out. Out!” he says, jabbing the pencil. Then there is the enigma of Eilis. One of the small miracles of Brooklyn is that the reader, and the other characters, care so much about a heroine who is strangely blank, passive, cold even. “Everybody wants her. You must have met someone like her, someone who, no matter what she does or doesn’t do, people just want to be around her,” he explains. “She casts no light. She just moves in shadow and things happen to her.” When people ask how he writes such convincing female characters, he always credits growing up in a house full of women. His aunts would come over every day and chat in the front parlour with his mother and two older sisters. “All sorts of things were being discussed, except sometimes what really mattered,” he recalls. “I would be watching and listening and they would often put me out of the room and I’d try and get back in again.” It was here that he heard about a girl home from America who took off her wedding ring on the boat so no one would know she was going to go back for ever. The sadness of the story stayed with him for years. The film was nominated for three Academy Awards. “They have a separate entrance for people like me. Honestly,” he hoots of Oscar night. “It’s very close to the red carpet entrance. It’s bad lino. It’s mouse colour. Nothing. It’s to get you quickly into the buildings. No one wants to photograph you. No one wants to interview you and everyone just wants you to go away.” He was sitting at the very back, and spent most of the evening getting drinks (before he’d given up the booze) from the Irish barman. By the time he got to the Vanity Fair party, it was a bit late: “Everyone goes to bed early in Hollywood.” A big fuss was being made over somebody, who turned out to be Lady Gaga. “How would I know that?” he asks. “Generally, I think it’s really important for novelists to go to those awards to realise you’re nobody and you’re nothing. And if you said to anyone, ‘I’m the guy that wrote that’, they would say ‘Are you famous? No, you’re not famous. You are some bald guy from Ireland?’” He does make an unmistakable cameo appearance in the queue of Irish immigrants just ahead of Ronan’s Eilis, waiting to enter America. “It was great fun.” And he approves of the film’s changed ending. “The pact with the audience is that you can’t just leave things hanging. I have to say, it’s the part of the film that I liked best.” When he’s invited to talk at Catholic universities in America, they are nervous to have a homosexual speaking, he jokes, “so they show the movie, which means it’s all kept clean”. He was particularly struck by the restrained performance of Domhnall Gleeson as the young Jim Farrell, who falls in love with Eilis that summer. “There are very few versions, anywhere in film or books, of a quiet Irishman, of someone stable, thoughtful, decent. Writers find them very difficult to handle. There’s no drama.” When he came to write the older Jim, bruised but not broken in midlife, he found Gleeson’s portrayal helpful. Irish novelist Paul Lynch won the Booker prize last year, and three other Irish writers were on the longlist – not to mention the success of authors such as Sally Rooney and Colin Barrett, both from County Mayo, as Tóibín points out. Tóibín is the latest incumbent of the Irish fiction laureateship and admires the freshness of the generation of writers coming up behind him, who he thinks are doing something new. “There is always a problem about representing Ireland,” he says. “Drunken people, fights breaking out, priests denouncing people from the altar, the IRA coming into the bar,” he lists, cautioning against Irish cliches in fiction. “It didn’t happen. Don’t do it. It’s not true.” Today Tóibín has sneaked past the police on campus due to the pro-Palestine student protests. He admires President Biden and fears that a Trump win in the election would be even more dangerous than before. “He’s both more unhinged and more controlled. He knows how you take the reins of government now, he isn’t on a learning curve,” Tóibín says. “And he’s much more racist than anyone thinks he is, his sense of white entitlement is really extreme. So in many areas he will move very fast, he will move very brutally, and he will have enormous control.” Everyone needs to do everything they can to stop Trump, he says of the growing “anti-Biden” sentiment among some American writers over the war in Gaza, “including holding their nose while voting for Joe Biden, if that’s what they need to do”. When he is not teaching in New York, he lives with his partner, the editor and writer Hedi El Kholti, in LA. “Los Angeles is a very good city to work in, because you don’t tend to go anywhere. You can’t just flâneur down the road and have a coffee and sit around reading the paper. Because there’s no coffee shop. There’s nothing in walking distance.” He writes from early in the morning to late at night – even later these days. “After dinner, I’m the most sober man in Ireland.” Would he ever come home? There’s no chance of his partner swapping sunny California for drizzly County Wexford any time soon, he says. “He’s not moving. So I’m staying.” But he will be in the UK this month for the publication of Long Island, and will spend a few days in the stylish house he had built on the cliffs above Cush, outside Enniscorthy. The beach has featured in his work since his first novel, The South, in 1990. “It has become a sort of magical place.” It is here that Eilis and Jim meet for the first time since her return from Long Island (she’s just come out of the sea, and the scene shivers with two decades of pent-up longing). “It’s tiny but exactly as described as Eilis walks along to that point,” he says. He tries to write part of each novel there. “Once I can do something on that stretch, it becomes sort of magical,” he laughs. “I mean a subdued sort of magical.” Long Island is published by Picador. To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply. Join Colm Tóibín for a Guardian Live event, live in London or via the livestream, on 23 May at 8pm BST. Book tickets at theguardian.com/guardianlive