JOHN Lanchester has been travelling on the London Underground a lot recently. No, he hasn't been battling through the capital to reach Olympic venues. It's because next year is the Underground's 150th anniversary and Lanchester has just finished his next book - about the Tube.
To be more specific, it's all about the District line, the green one that shuttles people across London via what used to be a home away from home for Australians, Earls Court. The book is part of a series on the system's tendrils by various writers. It will be published by Penguin - think of the distinctive colours of the Tube map and you can immediately envision the design.
But Lanchester won't be riding the rails for a while; he is avoiding London during the Games. His family are refuseniks. ''It's that classic thing. We were super keen and applied for tickets. But we didn't get any and then decided it was a terrible idea.''
That's why he is on the phone from Provence, where the Lanchesters - wife Miranda Carter, author of a couple of much-admired biographies, and sons Finn and Jesse - have taken refuge in a spot to which they go most summers. But he admits he has been hanging out with one of his neighbours watching more of the Olympics than he has for years. ''There has been a London feel-good factor, after all.''
Lanchester is one of those writers who seem to be able to turn their hand to anything. Fiction, tick; memoir, done; contemporary economic history, done; restaurant reviewing, two stints; journalism, with The London Review of Books and in The New Yorker. He made his name as a novelist with The Debt to Pleasure, in which he introduced the world to Tarquin Winot, bon vivant, epicurean and a man with dark secrets. It was strikingly original. He followed that with the very different Mr Phillips and then Fragrant Harbour, which drew on his childhood in Hong Kong. His memoir, A Family Romance, unveiled the secret of his mother's life that he learnt only the day before her funeral: he knew that she had been a nun, but not that she had been one for 15 years. And he had no idea that she had assumed the identity of one of her sisters and spent 40 years of her life claiming to be 10 years younger than she was.
And two years ago, Whoops! Why Everyone Owes Everyone and No One Can Pay grew out of some articles he wrote for LRB. It was a witty and damning account of the crash of 2008-09.
It's all to do with newness. Lanchester likes to write about different things in different ways. ''I don't sit down and think, 'I've done that, now I'll do this'. The bits that go towards a particular narrative technique or voice just get used up; that bit of me's not there any more.''
Whoops! actually emerged from his latest novel, Capital, which follows the residents of Pepys Road through that tumultuous year. So we meet Petunia Lowe, 82 years old and born in the street; Roger Yount, merchant banker, and his status-conscious wife, Arabella; the Kamals, who run the licensed newsagency at the end of the road. Various other people flit in and out - Zbigniew, the Polish builder; Freddy Kamo, who has come from Africa to play premier league football; Quentina Mkfesi, the traffic warden; and Smitty, the Banksy-like street artist who happens to be Petunia's grandson. And then there are the mysterious postcards that start appearing, saying: ''We Want What You Have.''
Lanchester started Capital towards the end of 2005, thinking the bust was coming. ''It was just in a commonsense way, following the logic of what goes up must come down. I was thinking in terms of there being a dramatic irony right from the start of the book, a dramatic irony in the classic sense of the audience knows something that the characters don't. When they're thinking things can only get better, the reader knows they can only get worse.''
When he'd finished the draft of the novel, he took his usual break from the work to allow him to see it more clearly down the track. He used the break to write Whoops!. Given that the plot of Capital is driven by the crash, I wondered whether he had rejigged the novel as a result of what he learnt while writing Whoops!.
He talks briefly about the distinction between specifics and truths, the former having more of a place in non-fiction with the latter belonging more in the novel. The other thing Whoops! made him do was ''quarantine'' some of the background details. ''I think explanation has a prophylactic effect on fiction.
''We'd have, 'Nigel looked out in the direction of Canary Wharf and struggled to remember the definition of a credit default swap' … I think the reader's just going to struggle to stay awake. I know that's a negative difference but it's quite an important one.''
The multiple points of view in Capital are perfect for Lanchester. Streets, after all, are full of stories and Lanchester often walks down one wondering what it would be like to know everything that's happening in other people's lives.
There is, he says, only one character who is consciously representative and that's Zbigniew. After the Poles joined the EU, a million of them migrated to Britain - ''the biggest number ever, including the initial Anglo-Saxon invasion that displaced the Celts'' - so he felt he had to have one in Capital.
''One day a guy was doing some painting in our house and he spoke almost no English but he had a laptop and he logged on - he'd asked - to the wi-fi and he was day-trading shares. He'd go off and paint a bit of the wall and then he'd check his stock portfolio. That really lodged in my head.''
So Capital, as its name suggests, is also very much about London. ''The world presses on London in an unusual way at the moment,'' Lanchester says. ''You get global issues that are very present; finance being so central to things that people are talking and thinking about. And inequality, too.
''Somalia implodes and suddenly there are 250,000 Somalis in London. Not so long ago it was the capital of a global empire and it's interesting that it's even more globalised and connected now. And it so wasn't.''
It is possible to see Capital as part of a trend in the British novel back towards storytelling. I wonder what Lanchester thinks about that?
In response he points to the turn away from the audience towards modernist preoccupations that every serious modern art form has taken - classical music, painting, sculpture - without turning back. ''The novel is the only one that has gone the other way,'' he says. ''I do believe in that thing about the reading audience being very important to the formation of the novel at its birth. Subsequently there's a gravitational pull of the audience and the idea that it's perverse, if there is such a thing as readers, to turn your back on them.
''I think the novel is in a very surprising place and a time traveller from, say, 1968 would be really struck by that, by this sort of turn towards not exactly populism or the popular, but the forms that were known in the novel. They are not made up of chopped-up fragments glued back together at random. They are plots and characters on a decent-sized canvas.''
Someone such as Edith Wharton, he says, would have no difficulty reading contemporary novels. ''She'd be a bit alarmed by some of the content, but in terms of the technique she would have recognised them.''
As he was preparing for Capital, Lanchester re-read George Eliot's Middlemarch. It had a significant influence because with the aforementioned modernist turn and the preoccupation with technical issues and point of view, he felt as an author he had less freedom to manoeuvre than someone writing in about 1850.
''I want to be able to know as much as I want and to go into and out of people's heads and be as omniscient or not as I choose,'' he says. ''Those 19th-century writers were very important in reminding me.''
Last month, Lanchester gave up his second stint of restaurant reviewing. He likes the idea of being a customer with a pen, but says you start to hit a problem when you know too much. In his final Guardian review, he addressed his nemesis, The Trip, by eating at L'Enclume in Cumbria, one of the establishments visited by Rob Brydon and Steve Coogan in their TV series. Now he wants to write about food rather than restaurants and in a longer form. You can expect him to dwell on umami (the savoury taste in Asian cooking), which he says is a preoccupation partly because of growing up in Hong Kong.
''I wanted to write about it by really properly talking to the experts and spending time with them and I couldn't combine that with being a critic.''
He's looking forward to being back in Melbourne later this month for the writers festival. His father was evacuated here during the war and went to Melbourne University. Lanchester loves the place. He first came in 1970 and then not again until 2001. ''In terms of places that have been changed irreversibly by immigration I think it's fascinating. It was like a magic wand had been waved. Also, I like good coffee. Places like Seattle make a fuss about it and French coffee is horrible. Melbourne is unequivocally fantastic.''
And if you're wondering where the fictitious Pepys Road is in London, the clue lies in its name. In 1701, the great diarist Samuel Pepys moved out of London to a small village in the country. Its name? Clapham.
■ John Lanchester is a guest at the Melbourne Writers Festival. Capital is published by Faber & Faber. The Age is a festival sponsor.