During my weeks in hospital the highway engineers had pushed its huge decks more than half a mile further south. Looking closely at this silent terrain, I realized that the entire zone which defined the landscape of my life was now bounded by a continuous artificial horizon, formed by the raised parapets and embankments of the motorways and their access roads and interchanges. These encircled the vehicles below like the walls of a crater several miles in diameter.

The silence continued. Here and there a driver shifted behind his steering wheel, trapped uncomfortably in the hot sunlight, and I had the sudden impression that the world had stopped. The wounds on my knees and chest were beacons tuned to a series of beckoning transmitters, carrying the signals, unknown to myself, which would unlock this immense stasis and free these drivers for the real destinations set for their vehicles, the paradises of the electric highway. The memory of this extraordinary silence remained vivid in my mind as Catherine drove me to my office at Shep-perton. Along Western Avenue the traffic sped and swerved from one jam to the next. Overhead, the engines of the airliners taking off from London Airport wearied the sky. My glimpse of an unmoving world, of the thousands of drivers sitting passively in their cars on the motorway embankments along the horizon, seemed to be a unique vision of this machine landscape, an invitation to explore the viaducts of our minds.

My first need was to end my convalescence and rent a car. When we reached the television-commercial studios Catherine drove aimlessly around the car-park, reluctant to let me out. Waiting by his car, the young rental-company driver watched us circle him.

'Is Renata going with you?' Catherine asked.

The shrewdness of this off-hand guess surprised me.

'I thought she might come along – handling a car again may be more tiring than I imagine.'

'I'm amazed that she'll let you drive her.'

'You're not envious?'

'Maybe I am a little.'

Sidestepping any local alliance that might be formed between the two women, I said goodbye to Catherine. I spent the next hour in the production offices, discussing with Paul Waring the contractual difficulties blocking the car commercial, in which we hoped to use the film actress Elizabeth Taylor. All this time, however, my real attention was fixed on the rental-company vehicle waiting for me in the car-park. Everything else – Waring's irritation with me, the cramped perspectives of the offices, the noisiness of the staff – formed a vague penumbra, unsatisfactory footage that would later be edited out.

I was barely aware of Renata when she joined me in the car.

'Are you all right? Where are we going?'

I stared at the steering wheel between my hands, at the padded instrument panel with its dials and control tabs.

'Where else?'

The aggressive stylization of this mass-produced cockpit, the exaggerated mouldings of the instrument binnacles emphasized my growing sense of a new junction between my own body and the automobile, closer than my feelings for Renata's broad hips and strong legs stowed out of sight beneath her red plastic raincoat. I leaned forward, feeling the rim of the steering wheel against the scars on my chest, pressing my knees against the ignition switch and handbrake.

We reached the foot of the flyover half an hour later. The afternoon traffic passed along Western Avenue and divided at the motorway interchange. I drove past the site of my accident to the roundabout half a mile to the north, circled and moved back along the path I had taken in the minutes before the crash. By chance the road ahead was empty. Four hundred yards ahead a truck climbed the overpass. A black saloon appeared on the shoulder of the slip road, but I accelerated past it. Within a few seconds we reached the impact point. I slowed and stopped the car on the concrete verge.

'Are we allowed to park here?'

'No.'

'All right – the police will make an exception in your case.'

I unbuttoned Renata's raincoat and placed my hand on her thigh. She let me kiss her throat, holding my shoulder reassuringly like an affectionate governess.

'I saw you just before the accident,' I told her. 'Do you remember? We made love.'

'Are you still involving me in your crash?'

I moved my hand along her thigh. Her vulva was a wet flower. An airline coach passed, the passengers bound for Stuttgart or Milan peering down at us. Renata buttoned her coat and took a copy of Paris-Match from the dashboard shelf. She turned the pages, glancing at the photographs of famine victims in the Philippines. This immersion in parallel themes of violence was a protective decoy. Her serious student's eyes barely paused at the photograph of a swollen corpse that filled a complete page. This coda of death and mutilation passed below her precise fingers as I stared at the road junction where, fifty yards from the car in which I now sat, I had killed another man. The anonymity of this road junction reminded me of Renata's body, with its polite repertory of vents and cleavages, which one day would become as strange and meaningful to some suburban husband as these kerb-stones and marker lines were to myself.

A white convertible approached, the driver flashing his headlamps as I stepped from my car. I stumbled, my right knee giving way after the effort of driving. At my feet lay a litter of dead leaves, cigarette cartons and glass crystals. These fragments of broken safety glass, brushed to one side by generations of ambulance attendants, lay in a small drift. I stared down at this dusty necklace, the debris of a thousand automobile accidents. Within fifty years, as more and more cars collided here, the glass fragments would form a sizable bar, within thirty years a beach of sharp crystal. A new race of beachcombers might appear, squatting on these heaps of fractured windshields, sifting them for cigarette butts, spent condoms and loose coins. Buried beneath this new geological layer laid down by the age of the automobile accident would be my own small death, as anonymous as a vitrified scar in a fossil tree.

A hundred yards behind us a dusty American car was parked on the verge. The driver watched me through his mud-spattered windshield, broad shoulders hunched against the door pillar. As I crossed the road he picked up a camera fitted with a zoom lens and peered at me through the eye-piece.

Renata looked back at him over her shoulder, surprised like myself by his aggressive pose. She opened my door for me.

'Can you drive? Who is he – a private detective?'

As we set off along Western Avenue the man's tall, leather-jacketed figure walked down the road to where we had parked. Curious to see his face, I made a circuit of the roundabout.

We passed within ten feet of him. He was sauntering in a loose, erratic walk among the tyre-marks on the road surface, as if miming some invisible trajectory within his mind. The sunlight picked at the scars on his forehead and mouth. As he looked up at me I recognized the young doctor I had last seen leaving Helen Remington's room at the Ashford casualty hospital.