It begins, as nights in London often do, with a rumour. Or rather: a grim promise. I had been told by a friend of a friend about giant hairballs clogging the sewers under the streets of the capital. Over the course of many years, tiny strands of hair moulted by millions of commuters had built up so that, lacquered by grease and dirt, they formed huge furry, knotted boulders that were swelling all the time. These hairballs, my informant whispered, had begun to develop a life force of their own; soon they would be bursting out of the sewers, rolling onto the streets and flattening pedestrians. I wanted to witness them at first hand: I would have to fight them, just as Raquel Welsh in One Million Years BC fended off murderous brontosauri with a pointy stick.
And so I head to Victoria Embankment where, on a sodden summer's night, I am poised above an open manhole cover on the brink of plunging underground in order, I hope, to face-off against the subterranean monsters that lurk below the city. If they exist, they are fewer in number than they used to be; a few yards away lies a monument to Joseph Bazalgette, the civil engineer who designed London's sewer system, bearing the inscription: "Flumini Vincula Posuit' ("He Chained the River'). He looks as whiskery and fervid as any 19th century empire builder, and that's what he was: a man driven by the urge to fight choleric murk and miasmic waste, to civilize and pacify the capital.
Here, near the banks of the river, everything is illuminated: the floating restaurants moored a few yards away; a blue-neon clad Hungerford Bridge; theatres emblazoned with the names of American actors in town to sprinkle a bit of Hollywood stardust on trad productions of repertory staples; St Paul's Cathedral in the distance. Packs of office girls totter home arm in arm after all-evening jolly ups, while lairy joyriders blow their horns and waggle their tongues furiously as they drive past them. Everyone seems to be hell-bent on having a good time. Everything seems safe and suburban.
To go underground though is to enter harsher, less secure territory. The flushers - or cleaners - who do so have to wear special protective outfits: a white paper boiler suit of the kind once sported by goggle-eyed ravers at German techno clubs; thigh-high waders with metal-toecapped boots; knee-high white socks; a safety helmet with a light attached to it; a steel box containing emergency breathing apparatus; a harness to winch them up in case of sudden floods or respiratory problems. They are kitted out thoroughly enough to deal with the end of the world.
And those who spend their working lives below London do inhabit the end of the world. The bowels of the earth, in fact. A place where day and night are interchangeable. Where darkness, uniquely for the capital, is perpetual. Its very essence. These Styx-dwellers manhandle everything that its inhabitants have abandoned and forgotten. They wade and crawl through its waste - its condoms, nappies, cotton buds, shit, fat - to clear blockages and keep the city above functional. They shuffle and tread through a rat-plagued and endlessly proliferating sub-universe, full of alleys, pipes, tunnels and side-tunnels so numerous that no single map exists to plot them all, that is invisible to most city-dwellers, and would repel them if it were not. If the 100-degree heat was not so intense, and their backs were able to withstand the pain-spasms, and they did not get lost in this sign-less republic, they would be able to trek east all the way from Hampstead to Beckton.
If you really thought about where you were going and what you were doing you'd either be shit scared or you wouldn't go there. We're shit shovellers. Some of the jobs I do a high percentage of the country would turn around and say: "Poke that up yer arse mate as far as you can put it.'
The modern city lionizes the idea of the underground. It is a synonym for buzz, edge, cool - perfumed and dematerialised concepts whose development and manufacture sustain huge swathes of the post-industrial economy. Now that "downtown' has been gazumped by real-estate moguls, "below town' has become the new avant-frontier. Paris, in particular, has a legion of catacombists and spelunkers who fashion crepuscular communities below the arrondisements. Yet London, a low-rise city much of whose mythology emanates from the ancient history embedded in its substrata, has no such tradition. The sewers are smaller and far less savoury than those on the Continent or in New York. Only the most daring or stupid adventurer would clamber down a steel staircase to reach them.
The flushers represent a small and dwindling tribe, all of them men, who deal with the reality rather than the poetics of subterranean London. A couple of decades ago there were over three hundred of them; now there are only 39. Their profession has been privatised and contractors, a growing number of them from Eastern Europe, perform many of the functions they used to. Semantic creep means that flushers these days are often labelled "water technicians'. Most of them have been working underground for two or three decades and this longevity, as well as their relative old age, makes them unusual, picturesque even, in a city where manual work is seen as marginal. "Us poor buggers are treated like bloody pit ponies," one complains, but that sense of injustice (the starting salary is little more than £18,000) is also allied to a fear that theirs is a waning vocation: "Young people today aren't willing to get out of bed every day, especially for the kind of money we earn, just to dive back underground again."
Have I seen ghosts? Well, you can imagine how that'd go down at the canteen, can't you - "Time you went home, my son, took a pill and went to bed.' Flushers'll say that they felt a change of draught or had a cold feeling. The mind is a horrible thing. To wander about in the sewers on your own would be a very unwise thing to do. Being underground is like a partial burial, innit?"
The sewers are often imagined as an unpatrolled, deregulated wilderness. They are imagined - and correspondingly desired - as the mephitic opposite of tamed civil society. They are meant to cancel it out. In truth, they mirror rather than reverse what goes on above ground. Flushers who work below Charing Cross Hospital complain about the overpowering smell of ether and about the number of times they have been stabbed by syringes while crawling on their hands and knees. Those who work below garages find themselves up to their necks in petrol. And those who happen to be rearranging the sludge below restaurants swear that they can tell whether it's come from an Indian or a Chinese takeaway.
Fat is the bane of flushers' lives. Millions of litres, from half-eaten breakfast dishes, chip-laden frying pans or fast-food joints, are tipped down into sinks each day. Eventually they find their way into the sewers. They represent the effluence of affluence. They are the graffiti that the contemporary leisurepolis scrawls on subterranean environments. Thirty years ago the Thames, unloved and abandoned, created few problems for flushers; now, the river's banks are congested with clubs, boozy eateries and art-complex gallery cafes all of them disgorging fat.
I wade through some of it at Victoria Embankment. It is at once crunchy and spongy, like putrid bran. Brown and white and grey: a pigeon-shit potage sprinkled with an extra top layer of mop heads and tampons. Flushers tell stories of accidentally getting a gobful of the sewer flies who feed on the fat or of metal grating giving way so that they fell into eight-feet deep fat-quicksands; the mouthfuls of the stuff they swallow leave their guts raw and hollering for months on end. But it's the bouquet that makes their flesh crawl: "You smell it initially. You breathe it all day long. You pass wind and what comes out is the smell of the fat. You can go home and shower as much you like - even with washing-up liquid - but at the end of the day you're still farting the smell of rancid fat. My wife'll say: "Oh, I see you've been sorting Fat Problems out..."
There is one story that many flushers in London like to recount. It concerns a fat iceberg that had been building up below Leicester Square over the course of a whole decade. Eventually, this 150-square-feet "slug of hardened fat" grew so large that it was impassable. A gang of flushers armed with supersucker machines spent six weeks one blazing summer trying to dislodge it. By the time they finished they were reduced to using ice picks to hack away at the white mountain.
It looks like a huge packet of lard. It shines in the dark and gives off this phenomenal transparent heat. Within ten minutes, as soon as you stick a shovel in it, you could slide through. The water comes at you like a dyke. The risks are colossal. Later, an animal food company got in touch because they wanted to buy and recirculate the fat."
The darkness of the sewers has the effect of amplifying and intensifying sounds. Ears need to work as hard as eyes to aid navigation through the curving tunnels that create an echolalia at once consoling (any cries for help will reverberate for a long time) and terrifying (scary, inexplicable noises will reverberate for a long time). Thin skeins of tree root thread their way down tunnel roofs and walls: they look like hanging microphones that curious city dwellers have unfurled to eavesdrop on a world they cannot see. No traffic or commuter roar can be heard here; they will pick up a constant susurration of distant waterfalls and squelching waders that can be heard alongside the murmur of near-adjacent Underground trains and the electronic ping of a machine that monitors carbon monoxide levels. Perhaps, like the flushers themselves when they stop for a while to adjust their equipment or to take a breath, they will make out the scratching of angry red cockroaches or of the rats that consider the sewers their home.
And, once in a while, they will hear the roar of flushers laughing. They'll cackle as a hungry gang member finds an orange among the dirt and fat and promptly starts eating it. Or at the desperate worker who loosens his uniform and has a dump in a corner. Life in the sewers is hard, and humour - the coarser and blacker the better - raises flagging spirits. A flusher tells me that he bought his wife a bouquet of flowers on their wedding anniversary. "I suppose you'll be expecting me to open my legs for you," she remarked. "A vase'll do," he replied. Another remembers the night he emerged from a sewer at Leicester Square dripping of filth and shit only to find a young woman tourist peering at him. He held out his hand: "Smell that. That's Canal No5, that is."
"One day, my son, if you work hard, and study all your books, you could get a job like this. Fucking hell, we do a unique job, but we're not designed to go underground: if we were we'd be moles and voles and rats and we'd have super-duper noses, have whiskers on, and be able to dig. It's an alien place for us."
I never did find the giant hairballs I was looking for. Apparently they don't exist. I shouldn't have been surprised: the sewers of London accumulate myths as much as they do fat. They are built out of a sediment of gossip, whisper, untruth, longing. Subterranea is alluring because it is thought, by autodidact dreamers and unstable visionaries, to contain the solution to the city, to store its hidden wiring. The streets become a horizontal curtain below which there paces up and down a magic controller, or at least a magic code that might be deciphered. At a time when gentrification is eroding much of the texture and historical gristle that made London what it was, is and should be, the sewers encourage necessary speculations about the existence of secret tunnels, through time as well as space, that might lead civilians to a parallel metropolis - Arnos Grove-meets-Atlantis, Snaresbrook-on-Shangri-La - in which a richer, deeper urbanism flourishes.
Although the sewers are no paradise they do contain treasures. Inching through them with only a helmet light to pierce the enveloping darkness, distant memories of being captivated by stories about Aladdin's Cave or Howard Carter discovering the tomb of Tutankhamen get rekindled. All flushers strike lucky once in a while and, most commonly under Cricklewood, St John's Wood and Formosa Street in Paddington, happen across something glimmering among the shit: chains, diamond rings, gold sovereigns. Their long-suffering wives are even more delighted.
The sewers are more than negation or black absence. They are rich in fragile beauty. The brickwork, some of it over two hundred years old, amazes all who work below ground. The red bricks and Portland cement, so smooth and enduring, put the modern fashion for concrete to shame. "The joints, the construction - it's marvellous," enthuses a flusher. "The people who built it could have thought: who gives a shit about this? It'll be hidden to most Londoners. It's only a sewer. But it's our workplace."
The light astounds: it bounces off the muddy water and the greasy streams and the curved tunnels at different angles, creating a fly-flecked and dust-particled vision that allows, for one brief but unforgettable moment, the smell and heat to be forgotten. The walls too can be minimalist canvasses, industrial cave drawings that reveal a fading archive of metropolitan graft: dates, some stretching back eighty years, of when repairs were carried out as well as the initials of the repairers. The flushers, unlike Bazalgette, will never be commemorated: some writing their names on underground walls with high-pressure jetters. Over time the endless wash of sewage rubs and distresses these inscriptions and self-memorials - as it does the flushers' bodies. Somehow, just, they endure.