"It was the feeling that everything I was seeing was just predictable," he says. "Was it possible to set out telling a story and not follow these paths? There's an idea about a line that I had explained to me by a painter friend. When a line goes out, there's a period before it turns into anything; before it becomes a face, a house, a tree: where it's just a line travelling, and it retains all its potential. I've always loved that idea, and I had something of that ambition for this book - that for as long as possible it would just be a line going out."
The book that resulted from this approach is an extremely unusual one, whose sheer waywardness might be spoiled by even a general precis. What begins as a cosy story about a couple of ill-matched students sliding into an early marriage soon takes several screechingly tight narrative bends, ushering its inscrutable protagonist Maud from a country cottage in Wiltshire to the kinds of physical, geographical and emotional extremes that test our assumptions about the kinds of things that should happen within the same story.
The effect is like reading a book of short stories, where every single narrative happens, in succession, to the same person: there's an episode of countryside philandering, a hair-raising sequence aboard a storm-tossed yacht, and a luminously strange conclusion in a foreign country where civilisation has taken a fascinatingly non-normal turn.
"I think it might piss off a lot of people," says Miller, looking quietly pleased about the prospect. "There was always the feeling with this book that I wanted the idea of being lost. In some sense that mirrors Maud's situation, but I was interested to have it in the writing, to allow it to flourish: to see how you make something while not really having any pure idea about the next step."
The thread that unites the novel's various parts is the character of Maud, a strange, tireless woman whose nature remains fascinatingly elusive to all the characters in the book - and, it turns out, to the author.
"In a way she's akin to various characters I've written about in the past," says Miller. "People who are slightly at a remove, who have difficulty around, if not feeling, then the expression of feeling and of emotion. She's someone who resists assimilation or interpretation, and I wanted her to be like that."
Everyone Maud meets in the novel seems to have an idea about her: one thinks she's on the autistic spectrum, another describes her as "one of those women who step out of a burning town and who, later, turn out to be the reason the town was burning".
Although Miller found Maud's physical prototype early in the novel - "I like to see if I can see my characters in the world, and I found her in someone sitting along the counter of a sushi bar in west London" - her cryptic, elusive character is pure invention.
"She's somebody who is, in a sense, an ordinary young woman from a very ordinary place," he says. "I picked the plainest English city I could, in Swindon. But she's also perhaps somebody out of a story we might recover on a fragment of stone, in some ruined city in the Euphrates Valley. I had flickerings of characters out of mythology, figures who are unstoppable: not in a kind of Terminator fashion, just a human being who keeps on going. It happens with sailors, people like Robin Knox-Johnston; you throw anything at these people, their boat is sinking, they're in terrible physical condition, but they just fix it and go on."
The restless impulses in The Crossing make a neat contrast with Miller's own life these days. After many years of writing and teaching in Spain, France and Japan, he took up residence in the Somerset countryside 10 years ago.
"The thing that changed everything was having a child," he says. "In Tokyo or Paris, I used to think: I'm here, but I could be anywhere - so why not? Why am I not living 500 miles down the road, or 10,000 miles across the ocean? Actually, I know why I'm here now. I'm here because my daughter's here, because this is where her school is, and that's it. It's been a very interesting period in the last few years. The sense of arriving, putting down roots, building a life in a different way, allowing yourself to be known and allowing yourself to know others."
The Crossing (Sceptre $37.99) is out now.
- Canvas, Telegraph