Lucy Irvine is holed up in a crumbling 1930s mudbrick house in the foothills of south-eastern Bulgaria, researching her fourth book. In October she will make a rare public appearance at the Wigtown Book Festival in Scotland, the first time she has been in the UK in more than a year. As the reclusive author admits, it's going to be a challenge.
"I am quite hermit-like these days and can become uncomfortable just being with other people," she explains, "which makes answering questions as thoughtfully as I'd like, difficult."
Being hermit-like is a trait that the author, now 52, has been renowned for ever since her first book, Castaway, made her internationally famous when it was released in 1983. An autobiographical work, the book told the story of Irvine's year on the desolate island of Tuin, in the Torres Strait between Australia and Papua New Guinea.
Irvine had answered a newspaper advert placed by a writer named Gerald Kingsland, who said he was looking for a wife to join him for an "experiment in isolation".
Although it was Kingsland who had originally intended to write a book about the adventure, it was Irvine's work which captured the public imagination. In 1986, Castaway was turned into a successful film of the same name, starring Amanda Donohoe as Irvine and Oliver Reed as Kingsland. The book was undoubtedly the author's big break, but she also says it has been crucial in her development as a writer.
"Undoubtedly Castaway defined me for others," she says. "For years, that was what I was seen as – the girl who lived for a year on an uninhabited island with a man she hardly knew. The experience itself – and that of writing the book, which was not planned when I went to the island – helped enormously to strengthen me as a person, and has informed my life ever since."
Any author would be shocked to see their first attempt at writing enjoy such success, both in the bookshops and on the big screen. But for Irvine, who had left school at the age of 12 and had never even considered becoming a writer, the experience was even more bizarre.
"I was surprised that so many people wanted to read the book, and wrote to me afterwards, and that thrilled me," she admits. "But I was never comfortable with a lot of media attention. I didn't go to live on a desert island with the intention of later being told what kind of dress to wear on a TV chat show in New York. But that's what happened."
Irvine is, by her own admission, inward-looking and awkward around other people. She says she developed a "habit of solitude" as a child, confiding in her diary instead of human beings, an instinct created by her tumultuous family life. She still refers to Western society as "the outside world", and is most comfortable inhabiting the position of an outsider looking in.
"I didn't only keep running away from school and home because I was discontented, but because I found it interesting," she says. "Not belonging to any particular group, I was free to observe. I drew word sketches of people's faces and actions. But I always kept a certain distance, and that habit has stuck. It's simply easier for me to live largely alone. And I could not write under any other circumstances."
Irvine's habit of isolation is borne out by her present home in the Balkan foothills, which she describes as "slightly savage". Rain pours through the roof in several places, and although the house has a terrace, she refuses to build any steps up to it – that would just be too civilised. "I don't want anyone to imagine it might ever be used for G&Ts," she says.
At one point in our emailed conversation, Irvine is forced to break off to attend to a crowd of Roma – Bulgarian gypsies – who have arrived clutching "peasant-uprising-sized hoes" to help her attend to her peach trees.
Irvine's description of her wider surroundings is a similar blend of the heavenly and the apocalyptic, and will delight anyone familiar with her writing. "The area is deeply rural," she says. "There are seven different kinds of delicious wild plum on the slopes of the mountain behind my house, and blackberries, sunflowers, roses, wild grapes and figs – as well as puppies' skulls from those chucked away to die, mauled cat carcasses and horrendous amounts of rubbish."
Having spent the past 14 months in Bulgaria observing the locals, as well as struggling with their language, Irvine says she is now in an "ideal position" to write her next book. It will examine four types of people: urbanites, rural folks, the Roma, and the outsiders or ex-pats.
Irvine was initially joined in Bulgaria by her youngest son, but he left to attend university in September and since then she has been largely undisturbed.
She has barely seen her two other sons, and says that seeing all three of them together is the main reason she agreed to travel to Scotland in October, where she is to give a talk appropriately entitled "Desert Island Books".
Other than the occasional brief visit, she says that she is unlikely to live in the UK again, and certainly not in a city. "One's way of life is fairly forcefully dictated by exterior influences in a city," she says. "You can't go anywhere without a welter of impressions being forced on you – and I'm not sure I could grow a tough enough hide for them to bounce off. I mean news, advertising, images, fixed ideas about lifestyles – all that din. The din often seems like an indecipherable code to me."
Irvine raised her sons on the remote Scottish island of Tanera Mor, and they even accompanied her to the Solomon Islands when she was researching her third and most recent book, Faraway. It told the true story of Tom and Diana Hepworth, a British couple who travelled to the area in 1947, aiming to raise a family on an island paradise.
Although she misses her sons immensely, she describes herself as "impossible to live with" and wants them to have the opportunity to lead normal lives.
"My sons tell me that taking them with me to the Solomon Islands was a very worthwhile experience for them, but the last thing I wanted was that they should feel like freaks when back in civilisation," she said.