Walking around Frank's apartment, I thought of him working in the prison garden, homesick for the Club Nautico. No doubt he was hungry for news and eager to see me, but a certain distance had opened between us. I felt too restless to spend any time in a gloomy invigilation room at the Zarzuella jail, hunting for clues to the truth among the nuances and studied vagueness of Frank's elliptical replies.

The sight of the Renault burning in the night had excited me. Roused by flames that seemed to leap across the bedroom ceiling, I ran to the balcony and saw the passenger cabin lit like a lantern, smoke swirling in the headlamps of the members' cars as they backed away to safety. One of the modern world's pagan rites was taking place, the torching of the automobile, witnessed by the young women from the disco, their sequinned dresses trembling in the flames.

When the pool party began as an excited response to the inferno, I almost changed into my swimsuit and joined the revellers. Trying to calm myself, I sipped Frank's whisky and listened to the shrieks and laughter as the sun came up over the sea, its copper rays touching the villas and apartment houses, a premonition of the last carnival blaze that would one day consume Estrella de Mar.

After lunch a replacement Citroen arrived at the Club Nautico, and the gutted wreck of its predecessor was hoisted on to the back of a breakdown truck. I signed the papers and then, out of curiosity, walked down the ramp to the basement garage. Frank's Jaguar sat in the pale light under its dust-sheet, police tapes around its fenders. A spare set of keys was in the concierge's office, but the thought of sitting behind the wheel made me uneasy. I took the service lift to the lobby, glad to leave the car to its dim underworld.

The tennis machine sounded across the lawns as the afternoon's practice sessions began. As ever, Bobby Crawford was busy with his trainees. Undeterred by his bandaged hand and arm, he moved restlessly around the courts, vaulting the net to retrieve a stray ball, skipping from one baseline to the next, cajoling and encouraging.

I thought of him sitting beside Paula on the balcony of his apartment on the morning after the speedboat chase in the harbour. I took for granted that he had set fire to the craft, not out of malice but to provide a handsome spectacle for the evening crowds, and that he or some collaborator had torched my rented Renault.

His motive, if any, seemed obscure, less an attempt to force me to leave Estrella de Mar than to integrate me into its inner life. I replayed the cassette of the porno-film shot in his apartment, still convinced that he was too committed to his fellow-residents in the resort to have taken any part in the brutal rape.

But had he murdered the Hollingers? So many witnesses had seen him at the Club Nautico's tennis courts at the time of the fire, but others could have acted for him. Someone with a taste for fire presided over the secret spaces of Estrella de Mar.

The tennis machine had fallen silent. Soon after four o'clock the players began to leave the courts and make their way home to a late siesta. Waiting for Bobby Crawford, I sat in the Citroen outside the bar where the amateur whores patrolled the night. One by one, the cars turned through the gates of the Club Nautico, drivers happily exhausted, dreaming of the perfect backhand brought to them by this handsome evangel of the baseline.

Crawford was the last to leave. At five-fifteen the shark-like snout of his Porsche appeared at the gates. It paused as he scanned the road, then accelerated past me with a throaty burble. He had changed from his tennis gear into a leather jacket, gangster-black against his white shirt, and his blow-dried blond hair gleamed from the shower. With his dark shades, he resembled a likeable young actor in his James Dean phase, chewing a knuckle as he pondered his next film role. Behind his head the torn roof liner fluttered in the wind.

I let a few cars pass and followed him towards the Plaza Iglesias. The Porsche waited at the traffic lights, exhaust thrumming among the motor-scooters and diesel taxis. With the sun vizor lowered, I pulled in behind a bus to Fuengirola packed with British tourists clutching their souvenirs of Estrella de Mar – miniaturized busts of the Apollo Belvedere, art deco lampshades and videos of Stoppard and Rattigan productions.

Untouched by snobbery, Crawford waved to the tourists, giving a cheerful thumbs-up to their choices. When the lights changed he pulled sharply to the right in front of the bus, barely missing the bull-bars of an oncoming truck, and set off down the Calle Molina for the old town.

For the next hour I trailed him around Estrella de Mar, along an itinerary that seemed to trace a secret map of this impulsive man's mind. He drove almost without thinking, and I guessed that he took the same route every evening when he finished his duties as the Club Nautico's tennis coach and set off to visit the outposts of a very different kingdom.

After a quick circuit of the Paseo Maritimo, he returned to the Plaza Iglesias and left the Porsche with its engine idling. He crossed the central gardens to the open-air cafe beside a newspaper kiosk, and joined the two brothers who spent their nights outside the doors of the Club Nautico disco. Edgy but affable, these former East End car-dealers sometimes offered me a generous discount on a new shipment of Moroccan hashish brought in by the powerful speedboat whose engines Gunnar Andersson tuned so expertly.

Leaving their iced tea, they stood up to greet Crawford with the deference of experienced NCOs towards a trusted young officer. They spoke softly as Crawford scanned his diary, ticking off entries in what seemed to be his order book. When they returned to their tea, supplies assured, Crawford signalled to a beefy Maghrebian in a dark uniform who sat at the shoe-shine stand.

This was Elizabeth Shand's chauffeur, Mahoud, who had watched me with his sour gaze while logging my licence number into his electronic notepad. After pressing a roll of pesetas into the shoe-shine boy's blackened hand, he joined Crawford in the Porsche. They circled the plaza, turned into a narrow side-street and stopped outside the Baalbeck Lebanese restaurant, a popular rendezvous and pick-up point for rich Arabs sailing down the coast from Marbella.

While Crawford waited in the Porsche the chauffeur entered the restaurant, and emerged moments later with two fair-haired women in gaudy tops, leather micro-skirts and white stilettos. They pretended to blink at the open air, as if sunlight was a phenomenon they had never experienced at first-hand. With their patent handbags they were dressed in a high-style pastiche of Pigalle streetwalkers, their garish garb incongruously assembled from the racks of Estrella de Mar's most expensive boutiques.

As the taller of the two hobbled along the narrow sidewalk I recognized under the platinum wig another of the mourners at Bibi Jansen's funeral, the English wife of a yacht-broker with offices at the marina. She was doing her best to play the whore, fleshing out her mouth and rolling her hips, and I wondered if this was all the whim of some avant-garde theatre director staging a street production of Mahagonny or Irma la Douce.

The women joined Mahoud in the back of a taxi, which sped towards the luxury apartment houses of the high corniche. Satisfied to see them off to work, Crawford stepped from the Porsche and locked its doors. He strolled past the parked cars in the side-street, right hand hidden in the folds of his jacket, testing the door latches. When the passenger door of a silver Saab opened to him he slipped into the driver's seat and reached under the steering wheel shroud.