I finished my drink, left a 500-franc note on the saucer and stood up to explore the night. I felt surprisingly light-headed, like a dreamer who had strayed onto a film set of tropical palms and cruise liners. At any moment an orchestra would strike up and the crowds on the Croisette, the Volvo dealers and Arab playboys and orthopaedic surgeons, would form themselves into a disciplined, arm-swinging chorus, belting out a big-band hit.

I followed the two prostitutes past the Noga Hilton, curious to see how far I could go before the puritan conscience pulled the plug. Uninspired by the car-dealers, the women locked arms and strode down the Rue Amouretti to the Place Dubois. They paused to scream abuse at a passing motorist, and veered away into the darkness.

Unable to keep up with them, I rested my knee outside Mère Besson. After scanning the evening's menu I set off towards the multi-storey garage near the railway station, where I had parked the Jaguar. A darker Cannes gathered itself around me once I crossed the Rue d'Antibes. Off-duty chauffeurs, Arab pushers and out-of-work waiters filled the narrow bars. They played the fruit machines, their thighs rocking the pintables until the tilt-signs flashed, an eye on the new arrivals who stepped from the Marseilles train, would-be construction workers and pairs of sharp-tempered young women who shouldered their way to the head of the taxi queue. Pimps ambled around the tunnel entrance to the underpass, a cloaca that drained away the festival city's dreams of lust and fortune.

Inhaling the heady air of north African tobacco, and the cheap aftershave of nerve-gas potency, I crossed the Rue Jaurès to the garage. I fed my ticket into the pay-machine as two men and a young girl walked down the concrete ramp towards the street.

With their leather jackets and hard shoulders, the men looked like plainclothes police, and I guessed that they had caught an absconding eleven-year-old trying to board the Paris express.

Neither of the men spoke to the girl, who trotted obediently after them, eyes lowered to the ground.

They paused in the entrance, the men searching the street. The girl heard the clatter of coins from the pay-machine, and turned to smile at me, as if pleased that I had won a jackpot. She was dressed in a French schoolgirl's blue skirt and white blouse, dark hair bunched behind her head. With her rouged cheeks, silver lipcoat and mascara she might have been any girl after an hour at her mother's dressing table. But there was nothing childlike about her gaze, and I knew that she was not on her way to the police station. She took in the passing traffic and the lights of the railway station, and then nodded to the men that she was ready to move on.

Forgetting the Jaguar, I walked down the ramp and followed the trio as they set off for the underpass. The Paris express was leaving the station, passengers standing at the windows of the couchettes, their cars stacked on the transporter wagons at the rear of the train. I entered the tunnel as the wheels bit into the steel rails over my head, a noise like pain through which the silver-lipped child walked and skipped.

In the nexus of narrow streets beyond the Boulevard d'Alsace congregated another constituency of the night: Maltese whores and their pimps, transvestites from Recife and Niteroi, runners for the dealers waiting in their cars off the Avenue St-Nicolas, smartly dressed matrons who seemed never to find a client but returned evening after evening, teenage boys waiting for the limousines that would ferry them to the villas of Super-Cannes, the mansions of light that rose above the night.

After dinner in the Vieux Port, Jane and I would sometimes detour through these shabby streets, amazed by the cool professionalism of the working children and the indifference of the local vice squad who made no attempt to rescue them. Thinking of the refuge at La Bocca, I remembered the zebra-striped dress and fishnet tights, and the Alice library that David Greenwood had so touchingly collected. Here in the Rue Valentin the Red Queen was a brothel-keeper and the only looking-glasses were the smudged mirrors in the whores' compacts.

A blond transvestite with the body of a rugby forward stepped into a streetlight, huge feet in a pair of stiletto boots, thighs exposed by minuscule satin shorts. His eyes swept the street, and followed a cruising car driven by a middle-aged man with the face of a depressed bank manager. The car paused and a door opened, and the transvestite dived into the passenger seat, filling the car like a gaudy circus horse.

A party of Volvo dealers, one with his conference name-tag on his breast pocket, watched the Arab factory workers bargainhunting among the bored whores. I followed the minders and their schoolgirl to the end of the Rue Valentin, where three unmarked vans were parked in a side street. A door slid back and a driver stepped onto the cobbled road. He spoke to the minders and then beckoned to the girl, who dutifully climbed into the passenger seat.

From the darkness around me mobile phones bleeped against the static of two-way radios. I glanced into the second van, where a fair-haired youth in a tracksuit sat behind the wheel. He steered his cigarette smoke away from his passenger, a girl of twelve who wore a Marie-Antoinette gown and silk shoes. She stared through the smeary windscreen, fingers playing aimlessly with a tasselled umbrella.

The schoolgirl I had followed from the garage was listening to the dashboard radio. Her chin bobbed to the disco rhythm, and she seemed cheerful and confident, adjusting the driver's mirror to check her lipstick, a vision of a child-woman as confusing as the doctor's daughter with whom I had first made love so many decades ago. That fumbling sex, the miracle of an attic mattress and a sharp-kneed thirteen-year-old biting my shoulder, had been beyond anything my boyish mind could imagine, promises of wonder that only returned when I saw Jane slumming around my hospital bed.

I opened my wallet and took out the photo-booth picture I had found in the Russian's shoe after our struggle beside the swimming pool. Even in the garish light of the Rue Valentin I could see the resemblance between the smudged image of a demure and placid child, photographed in a Moscow flat, and the mature schoolgirl rebunching her hair, raised arms pressing her small nipples against her cotton blouse.

'Natasha…'

I put away the photograph, trying to decide if she would still be here when I brought the Jaguar from the garage. With luck I could pay off her bodyguards, give them the slip and deliver the child to Sister émilie at La Bocca.

A black estate car turned off the Rue Valentin and stopped behind the vans. A well-groomed woman in her forties, dressed like a hostess working for a private airline, stepped from behind the wheel. She walked to the nearest van and spoke to the blond driver. He helped Marie-Antoinette from her seat, lifting her by the waist of her embroidered dress, and carried her umbrella as she ran in her silk shoes to the estate car. They left together, the child in the rear seat behind the woman driver, the van following with its headlights dimmed.

'Monsieur…? ça va…?'

One of the leather-clad minders strolled towards me, as if ready to discuss the next day's football matches. He lit a cigarette, cupping his hands over a brass lighter and revealing a high Polish forehead.

The schoolgirl noticed me, her head nodding at the music.

There was a brief smile as she remembered my jackpot win at the garage pay-station. Then she launched into a sales demonstration of herself, raising her chin and rocking her shoulders. Her eyes watched my hands, waiting for me to open my wallet.

I gestured towards the minder. 'Okay? You wait here with her. I'll bring my car.'

'Sept mille francs.'