'So there was no mystery about it?'

'Oh no, absolutely none, except why he did it. Mr Lessingham saw it happen. I'm surprised you remember it. There was very little about it in the national press. Alex tried to minimize the publicity to protect his parents.'

And to protect the power station, thought Dalgliesh. He wondered why Lessingham had described Gledhill's death as murder but he didn't question his companion further. The allegation had been spoken so quietly that he doubted whether she had in fact heard it. Instead he asked: 'Are you happy living on the headland?'

The question did not appear to surprise her but it did surprise him, as did the very fact that they were walking so companionably together. She was curiously restful to be with. He liked her quiet gentleness with its suggestion of underlying strength. Her voice was pleasant and voices were important to him. But six months ago none of this would have been enough to make him invite her company for longer than was politely necessary. He would have escorted her back to the Old Rectory and then, a minor social obligation performed, turned with relief to walk alone to the abbey, drawing his solitude around him like a cloak. That solitude was still essential to him. He couldn't tolerate twenty-four hours in which the greater part wasn't spent entirely alone. But some change in himself, the inexorable years, success, the return of his poetry, perhaps the tentative beginning of love, seemed to be making him sociable. He wasn't sure whether this was something to be welcomed or resisted.

He was aware that she was giving his question careful thought.

'Yes, I think that I am. Sometimes very happy. I came here to escape from the problems of my life in London and, without really meaning to, I came as far east as I could get.'

'And found yourself confronting two different forms of menace, the power station and the Whistler.'

'Both frightening because both mysterious, both rooted in a horror of the unknown. But the menace isn't personal, isn't directed specifically against me. But I did run away and, I suppose, all refugees carry with them a small burden of guilt. And I miss the children. Perhaps I should have stayed and fought on. But it was becoming a very public war. I'm not suited to the role of popular heroine of the more reactionary press. All I wanted was to be left alone to get on with the job I'd been trained for and loved. But every book I used, every word I spoke was scrutinized. You can't teach in an atmosphere of rancorous suspicion. In the end I found I couldn't even live in it.'

She was taking it for granted that he knew who she was; but then anyone who had read the papers must know that.

He said: 'It's possible to fight intolerance, stupidity and fanaticism when they come separately. When you get all three together it's probably wiser to get out, if only to preserve one's sanity.'

They were approaching the abbey now and the grass of the headland was becoming more hillocky. She stumbled and he put out his hand to steady her. She said: 'In the end it came down to just two letters. They insisted that the blackboard should be called the chalkboard. Black or chalk. I didn't believe, I still don't believe that any sensible person, whatever his colour, objects to the word blackboard. It's black and it's a board. The word black in itself can't be offensive. I'd called it that all my life so why should they try to force me to change the way I speak my own language? And yet, at this moment, on this headland, under this sky, this immensity, it all seems so petty. Perhaps all I did was to elevate trivia into a principle.'

Dalgliesh said: 'Agnes Poley would have understood. My aunt looked up the records and told me about her. She went to the stake, apparently, for an obstinate adherence to her own uncompromising view of the universe. She couldn't accept that Christ's body could be present in the sacrament and at the same time physically in heaven at God's right hand. It was, she said, against common sense. Perhaps Alex Mair should take her as patron of his power station, a quasi-saint of rationality.'

'But that was different. She believed her immortal soul was in jeopardy.'

Dalgliesh said: 'Who knows what she believed? I think she was probably activated by a divine obstinacy. I find that rather admirable.'

Meg said: 'I think Mr Copley would argue that she was wrong, not the obstinacy, but her earthbound view of the sacrament. I'm not really competent to argue about that. But to die horribly for your own common-sense view of the universe is rather splendid. I never visit Alice without standing and reading that plaque. It's my small act of homage. And yet I don't feel her presence in Martyr's Cottage. Do you?'

'Not in the slightest. I suspect that central heating and modern furniture are inimical to ghosts. Did you know Alice Mair before you came here?'

'I knew no one. I answered an advertisement by the Copleys in The Lady. They were offering free accommodation and food to someone who would do what they described as a little gentle housework. It's a euphemism for dusting, but of course it never works out like that. Alice has made a great difference. I hadn't realized how much I was missing female friendship. At school we only had alliances, offensive or defensive. Nothing "ever cut across political divisions.'

Dalgliesh said: 'Agnes Poley would have understood that atmosphere too. It was the one she breathed.'

For a minute they walked in silence hearing the rustle of the long grasses over their shoes. Dalgliesh wondered why it was that, when walking towards the sea, there came a moment when its roar suddenly increased as if a menace, quiescent and benign, had suddenly realized and gathered up its power. Looking up at the sky, at the myriad pinpricks of light, it seemed to him that he could feel the turning earth beneath his feet and that time had mysteriously come to a stop, fusing into one moment the past, the present and the future; the ruined abbey, the obstinately enduring artefacts of the last war, the crumbling cliff defences, the windmill and the power station. And he wondered whether it was in such a disorientating limbo of time, listening to the ever-restless sea, that the previous owners of Martyr's Cottage had chosen their text. Suddenly his companion stopped and said: 'There's a light in the ruins. Two small flashes, like a torch.'

They stood still and watched in silence. Nothing appeared. She said, almost apologetically: 'I'm sure I saw it. And there was a shadow, something or somebody moving against the eastern window. You didn't see it?'

'I was looking at the sky.'

She said, almost with a note of regret: 'Well, it's gone now. I suppose I could have imagined it.'

And when, five minutes later, they made their way cautiously over the humpy grass into the heart of the ruins there was no one and nothing to be seen. Without speaking they walked through the gap of the east window and on to the edge of the cliff and saw only the moon-bleached beach stretching north and south, the thin fringe of white foam. If anyone had been there, thought Dalgliesh, there was plenty of opportunity for concealment behind the hunks of concrete or in the crevices of the sandy cliff. There was little point and no real justification in attempting to give chase, even if they had known the direction in which he had disappeared. People were entitled to walk alone at night. Meg said again: 'I suppose I could have imagined it, but I don't think so. Anyway, she's gone now.' 'She?'

'Oh yes. Didn't I say? I had the distinct impression it was a woman.'

By four o'clock in the morning, when Alice Mair woke with a small despairing cry from her nightmare, the wind was rising. She stretched out her hand to click on the bedside light, checked her watch, then lay back, panic subsiding, her eyes staring at the ceiling while the terrible immediacy of the dream began to fade, recognized for what it was, an old spectre returning after all these years, conjured up by the events of the night and by the reiteration of the word 'murder' which, since the Whistler had begun his work, seemed to murmur sonorously on the very air. Gradually she re-entered the real world, manifested in the small noises of the night, the moan of the wind in the chimneys, the smoothness of the sheet in her clutching hands, the unnaturally loud ticking of her watch and, above all, in that oblong of pale light, the open casement and the drawn curtains which gave her a view of the faintly luminous star-studded sky.