He wrestled himself away from me, clambered to his feet and tried to kick my face. I gripped his right foot, wrenched his leg and threw him to the ground again. I began to punch his knees, but with a curse he picked himself up and limped away towards the avenue.

I lay winded on the grass, waiting for my head to clear. I fumbled for my walking stick, and found myself holding the Russian's calf-leather shoe. Tucked under the liner was a child's faded passport photograph.

'Taking on intruders is a dangerous game, Mr Sinclair.' Halder surveyed the diagram of scuff-marks on the lawn. 'You should have called us.'

'I didn't have time.' I sat in the wicker armchair, sipping the brandy that Halder had brought from the kitchen. 'He knew I was on to him and lashed out.'

'It would have been better to say nothing.' Halder spoke in the prim tones of a traffic policeman addressing a feckless woman driver. He examined the leather shoe, fingering the designer label of an expensive store in the Rue d'Antibes. Voices crackled from the radio of his Range Rover, parked in the drive next to the Jaguar. Two security vehicles idled in the avenue, and the drivers strode around in a purposeful way, chests out and peaked caps down, hands over their high-belted holsters.

But Halder seemed unhurried. Despite his intelligence, there was a strain of pedantry in the make-up of this black security guard that he seemed to enjoy. He switched on his mobile phone and listened sceptically to the message, like an astronomer hearing a meaningless burst of signals from outer space.

'Have they caught him yet?' I poured mineral water onto a towel and bathed my head, feeling the bubbles sparkle in my hair. Surprisingly, I seemed more alert than I had been since arriving at Eden-Olympia. 'He called himself Alexei. He shouldn't be too difficult to find. A man strolling around with one shoe on.'

Halder nodded approvingly at my deductive powers. 'He may have taken off the other shoe.'

'Even so. A man in his socks? Besides, it's an expensive shoe – welt-stitched. What about your surveillance cameras?'

'There are four hundred cameras at Eden-Olympia. Scanning the tapes for a one-shoed man, or even a man in his socks, will take a great many hours of overtime.'

'Then the system is useless.'

'It may be, Mr Sinclair. The cameras are there to deter criminals, not catch them. Have you seen this Alexei before?'

'Never. He's like a pickpocket, hard to spot but impossible to forget.'

'In Cannes? He may have followed you here.'

'Why should he?'

'Your Jaguar. Some people steal antique cars for a living.'

'It's not an antique. In a headwind it will outrun your Range Rover. Besides, he didn't come on like a car buff. Not the kind we're used to in England.'

'This isn't England. The Côte d'Azur is a tough place.' Concerned for me, Halder reached out to pluck some damp grass from my hair, and then examined the blades in his delicate fingers. 'Are you all right, Mr Sinclair? I can call an ambulance.'

'I'm fine. And don't worry Dr Jane. The man wasn't as strong as I expected. He's a small-time Russian hoodlum, some ex-informer or bookie's runner.'

'You put up a good fight. I'll have to take you on my patrols. All the same, you're still getting over your plane crash.'

'Halder, relax. I've wrestled with some very tough physiotherapy ladies.' I pointed to the faded passport-booth photo on the table. 'This child – it looks like a girl of twelve. Is that any help? He mentioned the name "Natasha".'

'Probably his daughter back in Moscow. Forget about him, Mr Sinclair. We'll find him.'

'Who do you think he is?'

Halder stroked his nostrils, smoothing down his refined features, ruffled by the effort of dealing with me. 'Anyone. He might even be a resident. You've been wandering around a lot. It makes people curious.'

'Wandering? Where?'

'All over Eden-Olympia. We thought you were getting bored. Or looking for company.'

'Wandering…?' I gestured at the wooded parkland. 'I go for walks. What's the point of all this landscape if no one sets foot on it?'

'It's more for show. Like most things at Eden-Olympia.'

Halder stood with his back to me, searching the upstairs windows, and I could see his reflection in the glass doors of the sun lounge. He was smiling to himself, a strain of deviousness that was almost likeable. Behind the brave and paranoid new world of surveillance cameras and bulletproof Range Rovers there probably existed an old-fashioned realm of pecking orders and racist abuse. Except for Halder, all the security personnel were white, and many would be members of the Front National, especially active among the pieds-noirs in the South of France. Yet Halder was always treated with respect by his fellow guards. I had seen them open the Range Rover's door for him, an act of deference that he accepted as his due.

Curious about his motives, I asked: 'What made you come to Eden-Olympia?'

'The pay. It's better here than Nice Airport or the Palais des Festivals.'

'That's a good enough reason. But…'

'I don't look the type? Too many shadows under the eyes? The wrong kind of suntan?' Halder stared at me almost insolently. 'Or is it because I read Scott Fitzgerald?'

'Halder, I didn't say that.' I waited for him to reply, watching while he twisted the Russian's shoe in his hands, as if wringing the neck of a small mammal. When he nodded to me, accepting that he had tried to provoke me, I turned my bruised ear towards the intercom chatter. 'I meant that it might be too quiet here. Your men have a job pretending to be busy. Apart from this man Alexei, there doesn't seem to be any crime at Eden-Olympia.'

'No crime?' Halder savoured the notion, smirking at its naivety. 'Some people would say that crime is what Eden-Olympia is about.'

'The multinational companies? All they do is turn money into more money.'

'Could be… so money is the ultimate adult toy?' Halder pretended to muse over this. He was intrigued by the stout defence I had put up against the intruder, but my excited sleuthing irritated him, and he was clearly relieved when the guards in the avenue walked up to the wrought-iron gate and signalled the all-clear.

'Right…' Halder glanced around the garden and prepared to leave. 'Mr Sinclair, we'll be stepping up patrols. No need for Dr Jane to worry. The Russian must have gone.'

'Why? He could be sitting by any one of a hundred pools here.

He's looking for David Greenwood – he didn't even know the poor man was dead.'

'So he went back to Moscow for a few months. Or he doesn't watch television.'

'Why would he want to see Greenwood?'

'How can I say?' Wearily, Halder tried to disengage himself from me. 'Dr Greenwood worked at the methadone clinic in Mandelieu. Maybe he gave the Russian a shot of something he liked.'

'Did Greenwood do that kind of thing?'

'Don't all doctors?' Halder touched my shoulder in a show of sympathy. 'Ask your wife, Mr Sinclair.'

'I'll have to. How well did you know Greenwood?'

'I met him. A decent type.'

'A little highly strung?'

'I wouldn't say so.' Halder picked up the Russian's shoe. He stared at the blurred photograph of the girl, rubbing her face with his thumb. 'I liked him. He got me my job.'

'He killed ten people. Why, Halder? You look as if you know.'

'I don't. Dr Greenwood was a fine man, but he stayed too long at Eden-Olympia.'

I stood by the pool's edge, and searched the deep water. The strong sunlight had stirred up an atlas of currents that cast their shadows across the tiled floor, but I could see the wavering outline of the silver coin below the diving board. Behind me the sprinkler began to spray the lawn, soaking the pillows of the chairs that Halder had moved in his hunt for evidence. The grass still bore the marks of colliding heels, the diagram of a violent apache dance. The raw divots reminded me of the Russian's frightened body, the reek of his sweat and the sharp burrs on his leather jacket.