‘Only don’t turn into a savage, Romain,’ she had said, standing at Euston, brave as a grenadier — and much more beautiful — to see him go. ‘Be particularly careful of your shirts — the starch must be just so. No thumping them on flat stones, promise?’

‘I promise.’

Then the train went and she cried a little in the ladies’ room and went on to the Summer Exhibition at Burlington House in a splendid herbaceous border of a hat because she was as gallant as she was good and knew that English ladies must not make a fuss.

Rom never repaid the money that she lent him. He waited two years and then went down to the Minas Gerais, that strange mineral-rich region of Brazil famous for its ornate and treasure-stocked churches, to seek out a hunchbacked craftsman who wrought precious stones into jewellery for the processional Madonnas. And a few months later a messenger arrived in Grosvenor Place and delivered a package which Madeleine opened to find — wrapped round a laundry receipt from Truscott and Musgrave — a necklace. A diamond necklace, each stone set in an intricately wrought halo of platinum, which her sensible husband — after a gasp of incredulity — fastened without too many questions around her lovely throat.

It was in an immaculate dress shirt from his laundry basket that Rom, delayed by a blocked feed-pipe on the Amethyst, entered his box in the Teatro Amazonas and saw — without undue excitement — the curtain rise on Act One of Tchaikovsky’s ballet Swan Lake.

‘I’m going to be sick,’ said Harriet.

‘You cannot be going to be sick again, ’arriette,’ said Marie-Claude, exasperated, turning from the long mirror where the girls sat in their tutus whitening their arms, putting on false eyelashes, applying Cupid’s bows to their mouths.

‘I can—’ said Harriet, and fled.

Act One had been called, but Act One is no business of the swans and the girls still had half an hour to complete their toilettes. It was a half-hour which Harriet did not expect to live through.

‘For heaven’s sake, there are eighteen swans in this production. Also two big swans. Also those idiot cygnets with their pas de quatre,’ said Kirstin when Harriet returned, green and shivering. ‘You don’t matter! Why don’t you tell yourself that?’

‘I know I don’t matter,’ said Harriet — and indeed no one could have lived for eighteen years in Scroope Terrace and not known that. ‘If I get it right, I don’t matter. But if I get it wrong… all those people who trusted me… Monsieur Dubrov and everyone… making the company look silly.’

‘You won’t get it wrong. I’m in front of you most of the time and when it isn’t me, it’s Olga,’ said Marie-Claude, piling up her golden hair and jabbing pins through the circlet of feathers in a way which would have driven the wardrobe mistress into fits. ‘Merde,’ she said softly — and indeed the head-dresses had not travelled well. She turned and dabbed a spot of red into each corner of Harriet’s eyes. ‘There is no need to whiten yourself. You look like a ghost.’

‘I must say, Harriet, such fear is excessive,’ said Kirstin. ‘What would your Roman emperor say?’

But for once the thought of the great Marcus Aurelius did little for Harriet. The famous Stoic had experienced most of the troubles of mankind, but it was unlikely that he had ever made his debut before a thousand people as an enchanted swan.

If Dubrov’s newest swan was nervous to the point of prostration, his ballerina assoluta was hardly in a state of calm.

‘Why didn’t you put it on the posters, that this was my farewell appearance?’ she yelled at Dubrov. ‘I asked you to do it — and you promised. A simple thing like that and you can’t do it!’

She was already dressed in her glittering white tutu. Beneath the shining little crown her gaunt face, trapped and desperate, was that of an old woman.

‘I will announce it after the performance, dousha.’

He did not waste breath telling her to relax, to be quiet. There was nothing to be done about her terror; she went on stage each time as if she was going to her death. All he could do was to be there, pray that the hundred instructions he had given to his underlings would be carried out and let her rage at him.

‘That cow Legnani! The first thing I shall do when I am retired is to go to Milan and slap her face!’

He sighed. Legnani, one of the world’s great ballerinas, had been the first to introduce the thirty-two fouettés which make Act Three of Swan Lake so fiendishly difficult to dance, and Simonova’s vendetta against her was unending.

She stopped pacing, came over, clutched him with feverish arms. ‘But this is the last tour, isn’t it, Sashka? Soon it will be over for good? Soon now we shall go and live in Cremorra and grow—’

But at that moment — fortunately for Dubrov, who was in no state to discuss the cultivation of vegetables — her final call came.

For Simonova, fine and experienced dancer that she was, the terror ended the moment that she went on stage. Alas, the same could not be said for Harriet.

Rom was not a balletomane. From his mother he had inherited a passion for the human voice and though he had refused all the other dignities that people tried to thrust on him, he had accepted the chairmanship of the Opera House trustees. To Rom fell the task of cajoling reluctant prima donnas from Europe; of arranging the entertainment for the cast. It was he who had taken six actors from a Spanish company to Follina to be nursed when they were stricken with yellow fever. But it was opera that held his heart and as the curtain went up on Prince Siegfried’s birthday revels, the plight of this young man — Maximov in silver tights and straining cod-piece — left him relatively unmoved.

Act One is something of a prologue. The Prince is bidden by his parents to marry, but feels disinclined. Pretty girls come up to dance with him and he supports their arabesques with the resigned look of a conscientious meat porter steadying a side of beef. His mother gives him a cross-bow… the eerie music of the swan motif is heard and the Prince decides to go hunting. The curtain falls.

The second act is different. A moonlit glade… romantic trees… a lake… And presently, Simonova gliding on — fluttering her arms, still freeing herself from the water. A fine dancer — Rom had heard her spoken of on a visit to Paris and she deserved her praise. The Prince appears and sees her… he is amazed. She tells him in absurd but effective mime that she is an enchanted princess, doomed to take the shape of a swan for ever unless a prince will truly love her. I will love you, signals Maximov; I will… They go off together…

And now to muffled ‘Ohs’ and ‘Ahs’ from the audience, there entered the swans. In his box the Prefect of Police, de Silva, leaned forward avidly, to be jerked back by the iron hand of his wife. The Mayor, squeezed like a small black currant between the bun-like figures of the Baltic princesses, smiled happily.

And Rom picked up his high-precision Zeiss opera glasses and fixed them on the stage.

As a youth, Rom had never doubted that he would be faithful to Isobel. The whole strange concept of a Christian marriage with its oaths, its unreasonable expectation that one man and one woman can find in each other all that the human heart desires, had found an echo in his ardent and romantic soul. When Isobel betrayed him, he put away these thoughts — and the kindness of Madeleine de la Tour had been for him a bridge to another and equally ancient tradition: that of woman as an amused and amusing source of pleasure. Of women, since he had come to the Amazon, Rom asked that they should be beautiful, willing — and know the score. And perfectly fulfilling these demands were the girls of the theatre who touched down here — bringing their experience, their flair and talent for the game of dalliance. Gabriella d’Aosta, a singer in the chorus of La Traviata, with her black curls and great boudoir eyes… Little Millie Trant from Milwaukee, who had played the part of the maid in a mindless American farce — a delicious girl who had extracted more jewellery from him than he had ever bestowed on a human female and been worth every carat… And the russet-haired, barefoot dancer, the poor man’s Isadora Duncan, whose high-mindedness had ended so delightfully after dark.

So now, though with considerably less excitement than in his former days, Rom raked his opera glasses down the line of swans.

In every chorus line there is one beauty and there now, fourth from the left and dancing with competent precision, she was. A blonde, surprising in a troupe of Russian girls, with big velvety eyes, a lovely mouth and perfectly rounded limbs. But as Rom followed her along the line of swans — nice girls, perfectly in step, doing rather fetching emboîtés — something peculiar happened. His extremely expensive opera glasses seemed to take on a life of their own, moving again and again to the left of the lovely creature he was pursuing in order to home in on the serious, entirely ordinary face of the girl beside her: a brown-haired, grave-eyed girl, the third from the left.

Only why? She danced with grace and musicality, but that was certainly not what had drawn him. Rather there seemed to emanate from her some extreme emotion: one that drew from him an instinctive feeling of protection and concern.

The swans had come to rest upstage, facing the audience, leaning their heads on their arms. The head of the serious brown-haired girl leaned very tenderly — she cared about the fate of her Queen — but Rom, watching her, saw now a faint but unmistakable trembling of her chin. She was frightened, very frightened indeed, and in an unexpected burst of empathy he saw what she was seeing — the infinite yawning gap of the auditorium with its blurred rows of potential executioners.