The sea at low tide reveals the isolated rocks that from a distance resemble figures reclining. We imagine them to be sea monsters sleeping even as the sun is rising on the sand. They are very still, not yet stirred by dreams that might wake them.

For a long time we did not see the slight figure so far away that she merged into the backdrop of cliffs. They are not the greyish white of the sea, but the pale yellow of the sun. The streaks of the sun's chariot are spreading across the sky. The figure is moving closer, one barefoot step on the sand at a time. The sand is smooth and glistening. The imprint of feet has formed a long trail from the horizon to the foreground where now we are able to make out her face framed by golden hair.

The closer she comes the lovelier she seems. It is a young face, alive to new experience but alert to the possible dangers. We are looking at an empty space where one can find an inspiring solitude, as she is doing. But an air of loneliness perpetually threatens to unbalance the perfect composure the painter has found in the scene.

Alone in the gallery, we spent a long time examining Portrait of Lysette, the girl in question [the artist's daughter] close up against a background of a coastal view we supposed to be where they were spending that memorable summer.

Memorable because here it was. Here she was, speaking now, her words indistinct at first. Gradually we could hear individual words spoken in a voice whose contours and cadences were from another age long past. All alive then were dead now except for she who had not aged a day in all the years that had passed. She was laughing, perhaps at the thought of growing old. She knew this to be impossible. Here she was.

And we were merely passing through. The sun was going to rise higher in the sky until by noon the world would be on fire, except of course for the air-conditioned gallery, that windowless cell in which time is captured alive and held for questioning by a future peopled for this moment by us.

She turns her back and walks away the way she came across the sand as the sun begins its slow descent into the sea. We know only that it is time for us to leave this room and move on to other scenes. Their number is infinite, or countless at least. Every second that has passed since the first was imagined.

It is of course possible to imagine any given moment in time. The artist's first sketch of his daughter by the sea, for example. Now we see on the portrait above his signature the hand that signed his name with a flourish [he was proud of his daughter's beauty]. Looking closer we can just make out the shadow of artist's head on his daughter's arm.

Her face, however, remains in sunlight, the clear light of early morning, gaining confidence as the sun rises. Lysette smiles. The artist is reminded for a moment of her mother. The moment in question concerns an incident by the sea at another time, the time of Lysette's conception in fact. She was conceived on the coast approximately at the spot where we see her now, where we have seen her before because she is always there or somewhere close by coming into view as the tide goes out.

A bird in a cage waits silently for her to feed it, as she does every morning of this summer.

There may be another figure glimpsed in the distance. She, too, is a shadow. Lysette inadvertently shields the figure itself from view. But, yes, we can make out what looks like the shadow of someone. The shadow moves, however, making it difficult for us to be sure who or what is behind.

We thought we knew who it was, but on reflection we cannot be certain. The artist will not say. He is concentrating on the figure in the foreground, the subject of his moment of vision, the picture by which he is best known. We can hear his murmurs without making out any distinct phrase. All we have are sounds that become brushstrokes as carefully he adjusts the scene to meet his variations of mood. Only one sentence is clear. 'Don't ever change, Lysette.'

Another time there may be clouds, or the sea will rise higher in a storm. But Lysette is always there somewhere in the scene, near or far. She has to be. It was her father's dying wish, for this is his last painting.

Is there a drop of blood on the grass? Looking closer, the eye can make out a small pool of blood. And so Lysette's face begins to lose its cheerful composure. This we have not noticed before. But, yes, from this angle we see there is a hint of anguish and another of fear. And, again she turns away. The terror she feels is not something to be shared nor even gazed upon.

The bird in its cage becomes anxious and violent. Soon it breaks loose and flies out of sight, never to return.

But when Lysette walked away where did she go? The scene changes to sky, almost a blank canvas. The artist is no longer there to see. His wife, a shadow, cries out for help. Her daughter is then found on a gallery wall, pinioned like a captive insect of a rare species in a museum of curiosities. Idle questions are asked that she never answers.

What happened to her we can do more than wonder. There is nothing for certain. Even biographies of her father say nothing further about her except that after her father's death she accompanied her mother to Geneva.

But can we imagine Lysette after her time in Geneva? Where did she go? And what became of her? There may have been fifty years beyond this, perhaps more. We are looking at someone born so long ago.

As a portrait she has seen so much. Lysette escaped war damage but was rescued from fire and a crazed attacker's knife. Untouched but vulnerable, she lives on into our time.

We are speaking of her gallery life. Of her other life there is less certainty. Her father's portrait of her was not the last picture. An older Lysette, it is thought, is a face in the crowd of Dumont's Boulevard, a photograph once familiar from many reproductions though barely known now.

She turns to look at the camera, suddenly aware that she is in view. It was the scene in general the photographer was wishing to capture. But the startled look of the ageing, still striking, beauty, added so poignantly to the scene that it helped make the photograph and photographer famous, if only for a time.

And that is really all we know. Lysette was in Paris on the Fourth of October 1912 at two thirty in the afternoon. [There was a clock close by about to strike the half hour]. It may have been the sound of the clock beginning its chime that caused Lysette to turn round.

In her dreams perhaps she recalled that day by the sea with some alarm that woke her, terrified, in the early hours. Somehow - it is not known exactly how - she attracted the attention of a Viennese doctor who attempted a cure of her crippling fear of art. 'I never see that portrait of mine, Herr Doktor,' she explained as she lay on the couch. 'I never see any pictures ever. I dream of an empty gallery in which I am trapped. There is nothing to see. And there is no way out.'

'A most interesting case, The Artist's Model, I have called her in one of my studies,' said the Viennese doctor, of Lysette [known to the world as Madame L.] 'Of course I mention no detail of names and other identifying points.' Such studies brought him immense prestige although he aroused controversy in his explanations of human behavior.

Later, exiled in London, he is able to see the picture for himself. It is newly arrived at the gallery after many years in a private collection. 'Ah, yes, I see it all now,' he says when he is found in the gallery, confused and in pain, staring out of the window, apparently at his own reflection.