'It's not Jane! It's nothing to do with her.' Frances shook my shoulder, as if trying to rouse a dozing sleeper. 'You're thinking of Penrose. You don't want to damage him.'

'That's not true.'

'Part of you believes in his lunatic ideology. That's why you've been so passive from the start. They corrupted your wife and you sat back and watched. I always wondered why.'

'You say I'm a voyeur.'

'That's not the reason. You secretly think Penrose is right, and a new kind of world is being born here, based on psychopathology. You're deeply impressed by Eden-Olympia. These vast companies with their powerful executives, sitting in their glass atriums like so many minotaurs. Once a year there has to be a sacrifice of six maidens. Except that it isn't once a year. It's every weekend, in the back streets of La Bocca. Still, who cares if a few teenage whores disappear into the labyrinth?'

'I care. Frances, I can see the flaws in Wilder's scheme.'

'Can you?' She turned to stare at me, as if understanding me for the first time. 'I know him a lot better than you do.'

'I'm sure you do. Did you have an affair with him?'

'Nearly.' She nodded bleakly to herself, unsettled by the memory. 'He helped me after the divorce. I needed support, and he was generous with his time. Wilder Penrose can be very attractive.'

'And very dangerous?'

'He frightened me. One moment there was all that smiling charm, the gentle giant with the strange new take on the world. The next moment he was going to hit me. I laughed at him over something and he raised his fist. I got out fast.'

'He was a boxer. Like his father.'

'He wanted to be, but something went wrong. He started to tell me about it – a fight after a rowing-club party with a nightclub bouncer, an old pro with early signs of brain damage that Wilder spotted. The man couldn't see anything coming from his left side…'

'So Wilder gave him a beating. Did he injure the man?'

'Badly, but that wasn't it. He saw all the repressed violence inside himself, the kind of violence his father wouldn't have liked. So Wilder decided other people would be violent for him, and he looked around for a system that could make it happen. Psychiatry was tailor-made for him. Once he'd dreamed up his ideology he could sit back and watch his patients getting their faces bloodied, all these repressed executives like Alain Delage that he's turned into playgroup Nazis. Now Wilder sees himself as a new kind of messiah, and our role is to act out his fantasies for him. Zander was right about Wilder Penrose.'

'And that's why he was killed.' I took her arms and held her to me, feeling her heart as it beat against her breastbone. We left the observation platform and walked back to the BMW.

'Let's leave before anyone notices your licence number – these accident widows must have sharp eyes. Listen to me. David died for something I believe in. I want to put Eden-Olympia on trial. I want Wilder Penrose to take the stand and be our chief witness.'

PART III

Applause eddied across the rows of guests, an approving murmur barely audible above the flapping of the canvas marquee.

Sitting beside Penrose in the second row of gilt chairs, I watched Olivier Destivelle, chairman of the Eden-Olympia holding company, bowing his thanks. With a theatrical flourish he accepted a silver trowel, presented on a velvet-lined tray by an attractive aide in a sky-blue uniform.

In front of the platform was a short section of newly laid brick wall, the pointing between the courses still damp and creamy. Set into the wall was a marble plaque, celebrating the foundation of Eden-Olympia Ouest, better known in the international business community as Eden II.

Dressed in his morning suit, and as plumply convivial as a retired matinée idol, Destivelle held the silver trowel in his manicured hands. He beamed at the audience of notables as he plucked a scoop of fresh mortar from a trestle table. Distracted by the photographers' flashbulbs, the television lights and the distant drone of advertising aircraft, he raised the mortar in a proud gesture, his nostrils flicking at the scent of quicklime.

Penrose leaned back in his chair, treating me to a stage whisper.

'Is he recommending a new truffle pâté? He's poncing about like the maître d' at Maxim's. Lay it, Olivier, don't taste it.'

Already bored, Penrose loosened his tie. He took off the jacket of his dark suit, exposing his heavy shoulders and crumpled sleeves. Nibbling at a thumbnail, he ignored the glares of the sleekly dressed women around us, wives of the Riviera elite in their ribboned hats and couture gowns. Humming loudly to himself, he gazed over the greenfield site towards the Alpes-Maritimes.

Buoyed by the prospect of the new business park that would be his next ideas laboratory, Penrose had been in good humour during our drive to the ground-breaking ceremony. Collecting me from the house, he was handsomely at ease in his black silk suit, and adjusted the rear-view mirror so that he could watch himself turn the ignition key. He made no attempt to reset the mirror, and waved my worries aside. 'Paul, do we need a rear-view mirror?' he asked as we left the enclave. 'Nothing can overtake us, so why look back into the past?'

The future was a second Eden-Olympia, almost twice the size of the original, the same mix of multinational companies, research laboratories and financial consultancies. Hyundai, BP Amoco, Motorola and Unilever had secured their plots, investing in long-term leases that virtually financed the whole project. The site-contractors were already at work, clearing the holm oaks and umbrella pines that had endured since Roman times, surviving forest fires and military invasions. Nature, as the new millennium dictated, was giving way for the last time to the tax shelter and the corporate car park.

A line of tractors and graders waited by the forest edge, drivers sitting at their controls, like a squadron of tanks at a military display.

The grass cover had been pared away, exposing the pale granitic marl to a few moments of sunlight before it was sealed away for ever under a million tons of cement.

'Progress, Paul, it's palpable…' When we left the car Penrose strolled to the refreshment tent, and gazed at the architect's model surrounded by a sea of canapés. Munching an anchovy, he smiled with pride at the landscaped office blocks, like a renaissance pope inspecting a model of his chapel and dreaming of the frescos he would never see. 'Look at it, Paul – the new Europe…'

'I hope not,' I commented. 'Eden II? It's another business park. You make it sound like Winthrop's City on a Hill.'

'It is, Paul, it is.' He seemed almost light-headed. 'A hundred cities on a hundred hills…'

A second round of applause rose from the guests as Olivier Destivelle patted the wet mortar into place. Within a year the ten-storey bulk of Eden II's administrative headquarters would tower above the plaque. As if signalling their approval, the massed engines of bulldozers and graders roared into life. Gearboxes rasped, metal tracks dug their cleats into the hard soil and a parade of yellow vehicles began.

Destivelle beamed at the lumbering parade, urging the spectators to applaud. But his eyes began to scan the sky. Half a mile to the north, a single-engined aircraft was heading towards us, towing a long green pennant like an agitated snake. It cleared a pine-covered hill, its fixed undercarriage almost scraping the canopy. The pilot flew on, scattered a flock of martins and set course for the phalanx of bulldozers, apparently intending to strafe them. Drivers watched over their shoulders, and already two of the huge vehicles had locked their scoops together.