The castors settled into their familiar ruts, but little else in Frank's world fitted together. I hung his scattered shirts in the wardrobe, and carefully folded the antique lace shawl in which we had both been wrapped as babies. After our mother's death Frank had retrieved the shawl from the bundle of clothes that Father had consigned to a Riyadh charity. The ancient fabric, inherited from his grandmother, was as grey and delicate as a folded cobweb.

I sat at Frank's desk, flicking through his cheque-book stubs and credit-card receipts, hoping for a pointer to his involvement with the Hollingers. The drawers were filled with a clutter of old wedding invitations, insurance renewal notices, holiday postcards from friends, French and English coins, and a health passport with its out-of-date tetanus and typhoid vaccinations, the trivia of everyday life that we shed like our skins.

Surprisingly, Inspector Cabrera's men had missed a small sachet of cocaine tucked into an envelope filled with foreign stamps that Frank had torn from his overseas mail and was evidently collecting for a colleague's child. I fingered the plastic sachet, tempted to help myself to this forgotten cache, but I was too unsettled by the visit to the Hollinger house.

In the centre drawer was an old photographic album that Mother had kept as a girl in Bognor Regis. Its chocolate-box covers and marbled pages with their art nouveau frames seemed as remote as the Charleston and the Hispano-Suiza. The black and white snaps showed an over-eager little girl trying hopelessly to build a pebble castle on a shingle beach, beaming shyly by her father's side and pinning the tail on a donkey at a birthday party. The flat sunless world was an ominous start for a child so clearly straining to be happy, and scant preparation for her marriage to an ambitious young historian and Arabist. Prophetically, the collection came to a sudden end a year after her arrival at Riyadh, as if the blank pages said everything about her growing depression.

After a quiet dinner in the deserted restaurant I fell asleep on the sofa, the album across my chest, and woke after midnight as a boisterous party spilled from the disco on to the terrace of the swimming pool. Two men in white dinner jackets were splashing across the pool, wine glasses raised to toast their wives, who were stripping to their underwear beside the diving board. A drunken young woman in a gold sheath dress tottered along the verge, snatched off her stiletto shoes and hurled them into the water.

Frank's absence had liberated his members, transforming the Club Nautico into an intriguing mix of casino and bordello. When I left the apartment to return to Los Monteros an amorous couple were testing the locked doors in the corridor. Almost all the staff had left for home, and the restaurant and bridge rooms were in darkness, but strobe lights from the disco veered across the entrance. Three young women stood on the steps, dressed like amateur whores in micro-skirts, fishnet tights and scarlet bustiers. I guessed that they were members of the club on the way to a costume party, and was tempted to offer them a lift, but they were busily checking a list of telephone numbers.

The car park was unlit, and I blundered among the lines of vehicles, feeling for the door latch of the rented Renault. Sitting behind the wheel, I listened to the boom of the disco drumming at the night. In a Porsche parked nearby a large white dog was jumping across the seats, unsettled by the noise and eager to see its owner.

I searched the shroud of the steering column for the ignition switch. When my eyes sharpened I realized that the dog was a man in a cream tuxedo, struggling with someone he had pinned against the passenger seat. In the brief pause between the disco numbers I heard a woman's shout, little more than an exhausted gasp. Her hands reached to the roof above the man's head and tore at the fabric.

Twenty feet away from me a rape was taking place. I switched on the headlamps and sounded three long blasts on the horn. As I stepped on to the gravel the Porsche's door sprang open, striking the vehicle beside it. The would-be rapist leapt from the car, the tuxedo almost stripped from his back by the frantic victim. He swerved away through the darkness, leaping between the Renault's headlamps. I ran after him, but he raced across the knoll beside the gates, straightened the tuxedo with a careless shrug, and vanished into the night.

The woman sat in the passenger seat of the Porsche, her bare feet protruding through the door, skirt around her waist. Her blonde hair gleamed with the attacker's saliva, and her blurred lipstick gave her a child's jamjar face. She pulled her torn underwear up her thighs and retched on to the gravel, then reached into the back seat and retrieved her shoes, brushing the torn roof liner from her face.

A few steps away was the booth from which the parking attendant kept watch on his charges during the day and evening. I leaned across the counter and snapped down the master switch of the lighting system, flooding the car park with a harsh fluorescence.

The woman frowned at the sudden glare, hid her eyes behind a silver purse and hobbled on a broken heel towards the entrance of the club, creased skirt over her ripped tights.

'Wait!' I shouted to her. 'I'll call the police for you…'

I was about to follow her when I noticed the row of parked cars that faced the Porsche across the access lane. Several of the front seats were occupied by the drivers and their passengers, all in evening dress, faces concealed by the lowered sun vizors. They had watched the rape attempt without intervening, like a gallery audience at an exclusive private view.

'What are you people playing at?' I shouted. 'For God's sake…'

I walked towards them, angry that they had failed to save the bruised woman, and drummed my bandaged fist on the windshields. But the drivers had started their engines. Following each other, they swerved past me towards the gates, the women shielding their eyes behind their hands.

I returned to the club, trying to find the victim of the assault. The fancy-dress whores stood in the lobby, phone lists in hand, but turned towards me as I strode up the steps.

'Where is she?' I called to them. 'She was damn nearly raped out there. Did you see her come in?'

The three gazed wide-eyed at each other, and then began to giggle together, minds slewing across some crazed amphetamine space. One of them touched my cheek, as if calming a child.

I searched the women's rest-room, kicking back the doors of the cubicles, and then blundered through the tables of the darkened restaurant, trying to catch the scent of heliotrope that the woman had left on the night air. At last I saw her beside the pool, dancing shoeless on the flooded grass, the backs of her hands smeared with lipstick, smiling at me in a knowing way when I walked towards her and tried to take her arm.