‘Well, we aim to please, sir. Most London cabbies see themselves as ambassadors for the city, part driver, part tour guide.’ Dave slowed the cab before the junction with Sussex Gardens, allowing a Hispanic woman wearing a fur-trimmed denim jacket to shepherd her great shelf of bosom across the road. He sensed the fare’s approbation like a sunlamp on his bald spot. ‘Now to the right here, sir, almost all the property between here and Baker Street is owned by the Portman family; not a lot of people realize how much of London is concentrated in the hands of a very few, very rich people.’

‘That’s very inner-resting.’

‘I’m glad you think so, sir, and this road we’re driving up, you may’ve noticed that it’s very straight for a London road, that’s because it’s the old Roman Watling Street.’

‘You don’t say.’ I do fucking say. I fucking know. I know it all – I hold it all. If all of this were swamped, taken out by a huge fucking flood, who’d be able to tell you what it was like? Not the fucking Mayor or the Prime Minister – that’s for sure. But me, an ’umble cabbie.

‘Yes, if we were here seventeen hundred years ago, we might’ve seen a legion marching off to Chester, on its way up north to duff up a bunch of blue-painted savages.’

The cab, its wipers ‘eek-eeking’, pulled away from the lights and scraped by the concrete barnacles of the Hilton tucked beneath the Marylebone Flyover. It was late lunchtime on a wet December day, so the shop windows were lighting up. Dave tried to imagine who – who he knew – might be the type to have pitched up in a room there, for no other reason but to smoke crack with brasses from the Bayswater Road and rape the minibar. From some dark rank in his memory a recollection pulled away: Superb Sid, Sid Gold . . . picked ’im up last year outside the Old Curiosity Shop . . . He was looking pretty fucking flush, pretty pleased with ’imself. Bespoke fucking whistle, cashmere overcoat, the whole bit. He wouldn’t’ve done me any favours if I’d reminded ’im of the perm he used to sport at school. He became a brief, didn’t ’e, criminal fucking brief – in both senses. Gave me his card. Ponce. Still, he’s the type I’m gonna need because that Cohen cow ain’t gonna come through. If I’m gonna see the boy again, I’m gonna have to get some dirt on that cunt Devenish. There has to be some . . . there always is . . .all you gotta do is dig.

‘My oldest son would be fascinated by this stuff,’ said the fare, who’d relaxed now they were trundling past Little Venice and up through Maida Vale. ‘He’s a history geek . . . gets it from his dad, I guess.’ The fare looked about him at the five-storey Tudorbethan apartment blocks, and, as if taking comfort in their solidity, unglued his hands from the handles and at last eased himself back in the seat.

Dave hit the intercom button – a plastic nubbin incised with a hieroglyphic head: ‘Yeah, I always think of Watling Street as a sorta time tunnel, connecting the past with the present.’ What’s the point in knowing there’s a time tunnel there if you’ve got no one to go down it with? Now I understand that I learned this city to hold in my mind for a while – then lose it to my boy. Without him it’s starting to disappear – like a fucking mirage.

Excerpted from The Book of Dave by Will Self Copyright © 2006 by Will Self. Excerpted by permission of Bloomsbury Press (USA). All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.