And there were other questions, one question in particular, which he had no need to fear from her. She wasn't in the least curious about his sexual life. He knew enough psychology to have at least some insight into what those early shaming and terrifying experiences had done to her. Sometimes he thought that she regarded his affairs with a casual, slightly amused indulgence as if, herself immune to

a childish weakness, she was nevertheless indisposed to criticize it in others. Once, after his divorce, she had said: 'I find it extraordinary that a straightforward if inelegant device for ensuring the survival of the species should involve human beings in such emotional turmoil. Does sex have to be taken so seriously?' And now he found himself wondering whether she knew or guessed about Amy. And then, as the flaming ball rose from the sea, the gears of time slipped, went into reverse and he was back only five days ago lying with Amy in the deep hollow of the dunes, smelling again the scent of sand and grasses and the salt tang of the sea as the late afternoon warmth drained out of the autumn air. He could recall every sentence, every gesture, the timbre of her voice, could feel again the hairs rising on his arms at her touch.

She turned towards him, her head propped on her hand, and he saw the strong afternoon light shafting with gold the cropped brightly dyed hair. Already the warmth was draining from the air and he knew that it was time they were moving. But lying there beside her, listening to the susurration of the tide and looking up at the sky through a haze of grasses he was filled, not with post-coital sadness, but with an agreeable languor as if the long-committed Sunday afternoon still stretched ahead of them.

It was Amy who said: 'Look, I'd better be getting back. I told Neil I wouldn't be more than an hour and he gets fussy if I'm late because of the Whistler.'

The Whistler kills at night not in daylight. And he'd hardly venture on the headland. Too little cover. But Pascoe's right to be concerned. There isn't much danger, but you shouldn't be out alone at night. No woman should until he's caught.'

She said: 'I wish they would catch him. It'd be one thing less for Neil to worry about.'

Making his voice carefully casual, he asked: 'Doesn't he ever ask where you're going when you sneak out on Sunday afternoons leaving him to look after the child?'

'No, he doesn't. And the child is called Timmy. And I don't sneak. I say I'm going and I go.'

'But he must wonder.'

'Oh, he wonders all right. But he thinks people are entitled to their privacy. He'd like to ask but he never will. Sometimes I say to him, "OK, I'm off now to fuck my lover in the sand dunes." But he never says a word, just looks miserable because he doesn't like me saying "fuck".'

'Then why do you? I mean, why torment him? He's probably fond of you.'

'No, he isn't, not very fond. It's Timmy he likes. And what other word is there? You can't call it going to bed. I've only been in your bed with you once and then you were as jumpy as a cat thinking that sister of yours might come back unexpectedly. And you can't say we sleep together.'

He said: 'We make love. Or, if you prefer it, we copulate.'

'Honestly, Alex, that's disgusting. I think that word is really disgusting.'

'And do you do it with him? Sleep, go to bed, make love, copulate?'

'No, I don't. Not that it's any business of yours. He thinks it would be wrong. That means he doesn't really want to. If men want to they usually do.'

He said: 'That has been my experience, certainly.'

They lay side by side like effigies, both staring at the sky. She seemed content not to talk. So the question had at last been put and answered. It had been with shame and some irritation that he had recognized in himself for the first time the nagging of jealousy. More shaming had been his reluctance to put it to the test. And there were those other questions he wanted to ask but daren't. 'What do I mean to you?', 'Is this important?', 'What do you expect of me?' And most important of all, but unanswerable, 'Do you love me?' With his wife he had known precisely where he was. No marriage had begun with a more definite understanding of what each required of the other. Their unwritten, unspoken, only half-acknowledged pre-nuptial agreement had needed no formal ratification. He would earn most of the money, she would work if and when she chose. She had never been particularly enthusiastic about her job as interior designer. In return his home would be run with efficiency and reasonable economy. They would take separate holidays at least once every two years; they would have at most two children and at a time of her choosing; neither would publicly humiliate the other;

the spectrum of marital offences under this heading ranging from spoiling the other's dinner-party stories to a too-public infidelity. It had been a success. They had liked each other, got on with remarkably little rancour and he had been genuinely upset, if principally in his pride, when she had left him. Fortunately marital failure had been mitigated by the public knowledge of her lover's wealth. He realized that to a materialistic society losing a wife to a millionaire hardly counted as failure. In their friends' eyes it would have been unreasonably proprietorial of him not to have released her with a minimum of fuss. But to do her justice, Liz had loved Gregory, would have followed him to California money or no money. He saw again in memory that transformed laughing face, heard her ruefully apologetic voice.

'It's the real thing this time, darling. I never expected it and I can still hardly believe it. Try not to feel too badly, it isn't your fault. There's nothing to be done.'

The real thing. So there was this mysterious real thing before which everything went down, obligations, habit, responsibility, duty. And now, lying in the dunes, seeing the sky through the rigid stalks of marram grasses, he thought about it almost with terror. Surely he hadn't found it at last and with a girl less than half his age, intelligent but uneducated, promiscuous and burdened with an illegitimate child. And he didn't deceive himself about the nature of her hold on him. No lovemaking had ever been as erotic or as liberating as their half-illicit couplings on unyielding sand within yards of the crashing tide.

Sometimes he would find himself indulging in fantasy, would picture them together in London in his new flat. The flat, as yet unsought, no more than a vague possibility among others, would assume dimensions, location, a horribly plausible reality in which he found himself arranging his pictures carefully on a non-existent wall, thinking over the disposal of his household goods, the exact location of his stereo system. The flat overlooked the Thames. He could see the wide windows giving a view over the river as far as Tower Bridge, the huge bed, Amy's curved body striped with bands of sunlight from the slatted wooden blinds. Then the sweet, deluding pictures would dissolve into bleak reality. There was the child. She would want the child with her. Of course she would. Anyway, who else could look after it? He could see the indulgent amusement on the faces of his friends, the pleasure of his enemies, the child lurching, sticky-fingered, about the flat. He could smell in imagination what Liz had never let him know in actuality – the smell of sour milk and dirty nappies, could picture the dreadful lack of peace and privacy. He needed these realities, deliberately emphasized, to bring him back to sanity. He was horrified that even for a few minutes he could seriously have contemplated such destructive stupidity. He thought: I'm obsessed by her. All right, just for these last few weeks I'll enjoy my obsession. This late summer would be brief enough, the warm unseasonable days of mellow sunshine couldn't last. Already the evenings were darkening. Soon he would smell the first sour tang of winter on the sea breezes. There would be no more lying in the warm sand dunes. She couldn't visit Martyr's Cottage again, that would be recklessly stupid. It was easy to convince himself that with care, when Alice was in London and no visitors expected, they could be together in his bedroom perhaps even for a whole night, but he knew that he would never risk it. Little on the headland was private for long. This was his St Martin's summer, an autumnal madness, nothing that the first cold of winter couldn't wither.