"How's that arm, Jenny?" he asked. "Getting better?"
"Yeah," she said, looking up.
The policeman stamped past, eyes already elsewhere. The woman turned back to her line of suited Londoners: "Anyone got a fag?"
Zero Tolerance, it seemed, was an easier police strategy to read about than to see practised. The Big Issue was selling well at King's Cross, with its Tony Blair interview about scorning and arresting beggars, about stopping the "small crimes" in this "frightening place". The day's newspapers were presenting Zero Tolerance as a law and order panacea, fresh from America. But controlling the concourse was a little more complex. "Zero Tolerance is the buzzword," said Inspector Bob Pacey with the weariness of a local policeman beset by national politicians. "Nothing's changed except the label."
In the briefing room on platform eight, Inspector Pacey explained that his officers' closer attention to behaviour on the station had begun in 1992. Operation Welwyn had chased the drug dealers and prostitutes; Operation Mistletoe, last November and December, had gone for brawlers and "aggressive" beggars; an alphabet of initiatives - observed by visiting officers from Norway to South Africa - had tramped past in between.
Their overall aims, set out on a noticeboard above Inspector Pacey's head, were more modest than MPs might hope: to increase detections per officer by five per cent a year, reduce attacks on passengers by three per cent, and robberies by one per cent. "To a degree you simply displace crime," said Inspector Pacey. "It's a never-ending cycle."
Around the station, the cycle was turning. At the far edge of the concourse, an adult woman with teenage lipstick waited against a wall. The wind jabbed along it, but she stared ahead, coatless. Just past her, by the phone boxes, a man in a puffy jacket was standing too, eyes flicking for the nod of a passer-by. Across the Euston Road, rigid in the wash of light from McDonald's and the late-night grocers', more people waited.
Yet King's Cross had shifted a little away from its reputation. The pavements were cleaner, the streetlamps brighter; surveillance cameras sprouted from them. Argyle Square, long the drinkers' oasis, was locked behind a brand-new fence, its old benches replaced by backless ones, Los Angeles- style, to deter slouchers.
Yet "target hardening", as local Labour councillors eagerly call it, is not enough. On Thursday evening, Inspector Pacey, paired with a colleague of 21 years' King's Cross experience, agreed to conduct a patrolling tour. Outside, the paving sparkled with new ice. The woman in the blue shirt was flitting round the Underground entrance. "She's cheeky," said Inspector Pacey. "Does it right in front of you." She moved herself on without a word. Then the policemen simply stood, their orange jackets like warning beacons, and a doughnut of space opened up all around them.
They spotted two men in a steamed-up bus shelter. The men were drinking; the policemen approached them; with a few beery curses, the men walked off, leaving a heap of lager cans. In a couple of minutes, they had been classified as "anti-social" in action or attitude or speech. "They'll be back in a few hours," said Inspector Pacey.
He was in no great hurry to find more. "Zero Tolerance is very resource- intensive. If you pick up someone for spitting on the platform, it means lots of paperwork. There are occasions when beggars are arrested and back on the station before our officers get back from court."
As the evening crawled coldly on, this pragmatism - "discretion" the officers called it - gained a philosophical weight. The police knew the station's shuffling poor better than its sprinting customers. Inspector Pacey's colleague had no sympathy for "city gentlemen who should know better", when they abused railway staff over train cancellations; but users of lighter fluid were known by their first names.
One of these, Daniel, was reported by a side entrance, trawling for pound coins. "He keeps his cans up his sleeves," said Inspector Pacey. "For sniffing - and spraying at people." We hurried round. He was gone - down into the Underground and out of Inspector Pacey's jurisdiction. "They have their own jungle telegraph," said his colleague. "They're a community."
Locally, however, they are not the only one. The streets around the station are dense with small shops, exhaust-stained flats, spines of council brick. Their residents may not be much richer than the street people, but they want them kept off their doorsteps.
The residents' loudest mouthpiece is a big man called Harvey Bass. He chairs their action group, heads the local Labour Party, and has harassed police and councillors about the area's "quality of life" since well before 1992. "I love King's Cross," he says. "I don't feel as if I'm living under a police state. You don't notice the cameras if you're not doing anything wrong." Mr Bass has lived in his "little village" since the Seventies; he thinks the tideline of used condoms and syringes is finally receding. Even the gutted old bank on the bag-snatcher's corner, by Gray's Inn Road, has scaffolding up for conversion to a police station.
Then again, the dirty water may be rising elsewhere. "Operation Welwyn did have a tendency to move the drug-dealing up the Pentonville Road [east of King's Cross] into the estates," says Alan Clinton, leader of Islington Council. Camden, to the west, has also felt the displacement of the station's crime.
But both councils would rather talk about regeneration: the new British Library, the Channel Tunnel Rail Link, a new quarter of shops and cafes and better flats for residents. Mr Bass used to fear a version of red- light Amsterdam rooting itself in King's Cross; instead, he may see a plant-tub Amsterdam of lofts and Victorian warehouse conversions. Away from the station concourse, in the cobbled grid of cleaned-up squats to the north, or the Bengali hustle to the south, pieces of this mild utopia are already in place.
Leading article, page 20