Zadie Smith's beautiful recovery from nausea

Zadie Smith is back. we caught up with the author at the launch of the Manchester Literature Festival where she was reading from her latest novel.

Seven years is a long time in literature. When Zadie Smith published her last book, On Beauty, there were plenty who liked her ambitious tale of a mixed-race British-American family living near Boston. It won the Orange Prize and was shortlisted for the Booker Prize. But as the years passed, there were murmurings that life in the public eye didn't suit her. In 2009, she said she felt "novel nausea". Any suggestions of weariness were unsurprising, really; her hugely acclaimed debut, White Teeth, was written when Smith was still in her early 20s.

And then, at the launch for the Manchester Literature Festival, Smith, now 36, read from her new novel NW. She chose a wonderfully warm section, where a young man is taken to task for smoking in a playground. And people laughed out loud. It was a reminder that there aren't many authors as adept as Smith at capturing dialogue. Just on the basis of that excerpt, the queue to buy her new novel snaked around the Victorian town hall. Zadie Smith was back.

NW is a fascinating book, following four characters who are, like Smith, in their 30s. All born on the same housing estate in London, Leah, Natalie, Felix and Nathan attempt to make sense of their lives as they leave Caldwell - there's crime but there's also university, happiness and anxiety. But its real achievement is that it doesn't feel like a hyperlocal novel, which will only make sense to the people of London. NW is about how such disparate people live, on top of each other, in a city.

"People often say that London is unique in having that cheek-by-jowl existence," Smith said to her audience after the reading was over. "But I'm not so sure it's that unusual anymore. If you go to Mumbai or New York, you see it, too. What has always interested me is how that city logic affects people. How people walk past someone in the street with no shoes. Does that make them an unethical person? Of course not."

In fact, the book opens with a scam: a girl knocks on the door and tells Leah she needs £30 (Dh180) to get to her mother, who has had a heart attack. But she really needs the money for less noble purposes.

"It got me thinking, well, if you're desperate, where is the scam?" said Smith. "The desperation isn't fake. The culture I grew up in, you end up analysing good acts. Did you do them to make yourself feel good, to salve your conscience? It seemed an interesting way to start."

One of NW's main themes is time. Smith talks of it appearing to speed up with age and bravely attempts to replicate that feeling in the structure of the book, which has wildly different storytelling techniques. "It makes for an uneven and strange form, but then, that's how life is, too," she said. "I'm really interested in what memory feels like. How time feels. I mean, in most novels, someone will sit down and have a 40-page flashback, but that's not actually what real life is like, is it? We only have snapshots of a past, maybe 12 or so clear memories from childhood. It wasn't about being experimental, it was about finding something true."

So in the week the Booker shortlist was announced, it seems bizarre that Smith, armed with a book that so clearly states the case for the relevance of 21st-century literary fiction, didn't even make the longlist. Not that she would mind.

"The thing is, with all of these awards I have won in the past, it's always been like people are talking about someone else," she laughed. "The feeling of 'did I really write this book?' is genuine."

She really did. Not least because nobody writes quite like Zadie Smith.

NW (Penguin) is out now The Manchester Literature Festival starts on Monday