But Pinny’s house was only the beginning. Anna had run upstairs to change into her only ‘good’ dress — a green velveteen which Kira had sent from Paris. The Countess Grazinsky gathered up shawls, leaking packets of tea and lorgnettes, and when Pinny was satisfied that the little girl was properly rested they set off for the Russian Club.

For the rest of her childhood, if anyone asked Ollie what she wanted to be when she grew up, she always replied: ‘A Russian.’ The club was on the first floor of a large, dilapidated house behind Paddington Station, but the trains which shook its foundations every few minutes might have been travelling, not to Plymouth but to Minsk, not to Torquay but to Vladimir the Great, so exotic and foreign were its delights.

For there really was a stuffed grandmother. She lived — so everyone swore — in a most beautiful and gaily painted chest which stood under one window. The chest was heavily padlocked and covered with a crimson gypsy shawl and no one would have dreamt of putting down a tray of glasses or a plate on it without saying, ‘Sorry, Baboushka’, or ‘Forgive me, Ancient One’. Nor was there anything sad about her, as Anna was quick to explain. For the old lady had belonged to the two pale young men, Boris and Andrey, who now owned the house the club was in and spent their time at a corner table playing Halma and planning to assassinate Lenin. Boris and Andrey had adored the old lady and when she died had, with the help of a famous Egyptologist, found this way of keeping her with them when they fled their native land. Or so they said.

Above the Baboushka there hung an icon of St Cunouphrius, the saint who grew a beard to cover his nakedness and whose stick-like arms and little, white legs were all that protruded, wistfully, from behind the curlicues of coal-black hair. Beside him, there was another picture showing forty martyred bishops busily freezing to death in their shifts on an ice floe, and beneath them was a small shrine containing a crimson icon lamp, a bunch of withered marigolds, a lump of bread and a packet of Cerebos salt. There was an enormous, stuttering, smouldering samovar of fluted brass…

And there was Pupsik himself, the mythical dachshund, his sagging extremeties hanging exhaustedly over the edges of a low footstool which had become a kind of altar. Pupsik, to whom his owner the Baroness de Wodzka had fed, in a moment of panic on the Finnish border, the Rastrelli diamond embedded in a chunk of liver sausage. A priceless diamond, the baroness’s only remaining jewel, which somehow, mysteriously, the ancient, wheezing animal had managed to retain in some diverticular abnormality along the clogged and malodorous drainpipe of its body… Every day during the six months of his quarantine, the baroness had rung the kennels, terrifying the kennel-maids with her imperious, ‘Vell? ’ass ’e voided?’

But Pupsik, though functioning normally in other respects, had not voided the jewel.

Bets had been laid, horrendous physiological disputes had split the club — but Pupsik, returning from quarantine to find himself famous and feted, continued to deprive the baroness of the jewel which would have reunited her with her children in America, secured her a livelihood, a home.

Anna’s entry, with her mother, her governess and Ollie, was the signal for an explosion of hugs, kisses and endearments. The Princess Chirkovsky, Sergei’s mother, enveloped her in an enormous motheaten chinchilla stole; a grey-bearded poet who had been writing verses to her since she was six years old rushed forward with his latest ode. Colonel Terek, who had parked his taxi in the mews, went for more vodka…

For a few moments, Anna gave herself up to the joy of being welcomed. Then she held up her hand and, switching to English, said: ‘I have brought you a very special friend of mine, Miss Olive Byrne. She has been a little bit sad and I have told her that here it is possible to be instantly and completely happy. Was I correct?’

And the party began.

An hour later, Ollie had reached unimaginable heights of glory. Her health had been drunk and the glasses thrown away so that no lesser toast could ever be drunk than the one dedicated to her. Gentlemen behaved in this way in the presence of beautiful women, Anna explained, and she must accustom herself to it. Now she was not only sitting on the stuffed grandmother, but holding in her arms the greater part of the dachshund, Pupsik, bestowed on her by the Baroness de Wodzka herself. On either side of her, as unobtrusively watchful as the Praetorian guard, stood Pinny and Sergei’s erstwhile governess, Miss King. Boris and Andrey, the pale young counter-revolutionaries, were playing the balalaika; Princess Chirkovsky, waving her arms, was expounding to Anna’s mother her latest, absolutely sure-fire method of retrieving the family fortunes: the setting up of a piroshki stall on Paddington Station.

As for Anna, she was everywhere — dancing with a huge blond Cossack, flirting with the eighty-year-old admiral who had lost an eye in the Tsushima Straits, picking up her mother’s shawls — but always returning to Ollie to give the little girl a hug, a smile.

‘Everyone wants to be with Anna, don’t they?’ she said to Pinny, to whom she could have said nothing that would endear her more.

But suddenly something happened. Anna had stopped dancing and was standing stock-still in the centre of the room, her face turned to the door. The colour drained from her cheeks; her clasped hands flew to her mouth…

Then everyone saw what Anna had seen; a tall, tanned, staggeringly handsome man in a dove grey uniform with a high collar, standing in the doorway. The next second, pandemonium broke loose. The Princess Chirkovsky rose, let out a scream and rushed forward, overturning her glass of tea. Miss King, the Countess Grazinsky and a crowd of others followed. Pupsik woke, barked, and slithered out of Ollie’s arms on to the floor.

Only Anna stood still in the centre of the room, hugging her joy.

Then Sergei saw her and parted the people that were between them and she was in his arms. They had shared a childhood and a country. They had not seen each other for three years and, for two of them, Anna had believed him lost. Now, even their excited ebullient compatriots were silent, awed by the measure of their joy.

‘Annushka! Milenkaya… dorogaya…’ He put up a finger, brushed away her tears. ‘Is it you… is it really you?’

Anna could not speak. She just stood looking up at him, letting the tears run down her face, while Sergei pulled her close to hug her, then away so that he could see her, and closer once again.

But even in this moment of homecoming and happiness, Anna did not long forget the little girl whose wound she had set herself to heal, and presently she dried her eyes and led her cousin over to where Ollie sat.

‘Sergei,’ she said, ‘I want you to meet a very special friend of mine. Miss Olive Byrne.’

Sergei, from his great height, looked down on Ollie. He clicked his heels and bowed. Then he reached for Ollie’s hand, turned it over and kissed the palm.

‘Enchanté, mademoiselle,’ he said gravely. ‘Permit me to say that all my life I have wanted to meet a girl with hair the colour of a sunset over the steppes.’

Ollie tilted her head at him. Sergei’s gold-flecked eyes were warm and tender, the smile that lit his lean, tanned face and showed his dazzling teeth was unforced, caressing and perfectly sincere.

She stared down at her kissed palm and up again. And unhesitatingly, uncomplainingly, joined the long, long line of women that were in love with Anna’s Cousin Sergei.

While Ollie was being feted at the Russian Club, Rupert was being led into an upstairs room at Aspell’s, the discreet and world-famous jeweller in Bond Street. Mr Aspell had intended to deal with a client such as Lord Westerholme himself, but Rupert was early; Mr Aspell was still at lunch and it was to old Mr Stewart, whose dry and scholarly exterior hid a deep and romantic passion for rare stones and their history, that Rupert explained his errand.

‘Sapphires… Ah, yes.’ The dry fingertips met, the gold pince-nez fixed themselves on the good-looking young nobleman. ‘What kind of sapphires had you in mind, my lord?’

Rupert smiled. ‘I’m afraid I thought sapphires were just sapphires.’

‘Oh, dear me, no! No, no, not at all.’ Mr Stewart, shaking his bald head, looked quite upset. ‘There are sapphires so dark as to seem almost black in certain lights. Siamese sapphires are like that. So much so that they have been used as mourning jewels during certain periods of history. Then again the Australian stones are almost turquoise with a light, translucent quality that is very characteristic. They’re not quite so valuable, but very pleasing. Whereas certain star sapphires are quite grey in tone…’

‘I see. Well then I’m afraid the limitation may be one of price. I’m not very well off.’

Mr Stewart nodded sympathetically. ‘Yes, quite. Well, this is an exceptional time to pick up a bargain. We are getting some quite outstanding pieces at a very reasonable price from the Russian emigrés. For example, we would be in a position to offer you the Galychev necklace of one hundred and seven cabochon sapphires, each stone weighing not less than thirty carats. Or we are acting as agents for Madame Bogdanin — she is selling off a chain of Burmese stones with an exceptionally fine gold-beaded mounting by Fabergé. No one, in my view, can set jewels like the Russians.’ He sighed. ‘Of course, if I could have offered you the Grazinsky sapphires…’

Rupert leant forward, wondering why his heart had begun to race. ‘The Grazinsky sapphires?’ he prompted.

Mr Stewart nodded. ‘I have never seen such sapphires. Never. It was as if God had at that moment invented the colour blue and wanted it preserved for ever in those stones. It was almost a religious experience to look at them.’

He glanced up, suddenly anxious, for he was aware that of late he had begun to reminisce and ramble in a way that betrayed his age. But the earl’s silence was one of total attention.

‘All the Grazinsky jewels were like that. Beyond price, beyond belief… There was a triple row of pearls with which I suppose one could now purchase Blenheim Palace. I’ve never seen such pearls anywhere. Even in Russia they were a legend and what country understands pearls like the Russians do? Every nursemaid pushing a perambulator has a kokoshnik studded with them. But these… They had the Potempkin pendant, too, and of course the emeralds. They were one of the great showpieces of the world, the Grazinsky emeralds.’

‘You sound as though you have seen them yourself?’ said Rupert.

The old man nodded. ‘Yes, I went out to Russia… oh, twelve years ago it would be now. The autumn of 1908. I was collecting material for a monograph on eighteenth century court jewellery. The period of the Empress Elizabeth.’ He smiled apologetically. ‘It’s my speciality. It may seem dry to you, but I assure you—’

‘No, no, not at all,’ said Rupert. ‘I’m extremely interested. Did you actually meet the Grazinskys?’

‘I didn’t just meet them, I stayed with them. They invited me for as long as I wished. People tell me,’ said Mr Stewart, removing his spectacles and polishing them, ‘that Russia was corrupt, that the revolution was necessary — and I have no doubt that they are correct. But all I can say is that never in my life have I experienced such hospitality… such democracy as I experienced in that house. But I must say their attitude to their jewels amazed me.’

‘In what way?’

‘It’s not easy to put it into words. To a certain extent, all Russians are like that. They treat their jewels — not carelessly, exactly — on the contrary, they glory in them. After all they’re halfway to the Orient. But it’s almost as if they thought of them as… family friends or household pets. For example the Grazinskys didn’t keep anything in the bank — it was all just lying about the house. Once — I really couldn’t believe my eyes — I was invited into one of the upstairs salons and found the baby lying on a bearskin rug — and playing with the Crown of Kazan!’

He looked up to gauge the effect of this on his client.

‘I’m afraid you’ll have to enlighten me,’ said Rupert. ‘I’m very ignorant about jewellery. What is the Crown of Kazan?’

‘You may well ask, my lord. It’s a fifteenth century piece; it ought to be in a museum, let alone a bank. Enamelled, gold-studded with uncut rubies and diamonds… The countess used to wear it to costume balls — and there was the little boy dribbling on it! His sister had given it to him because it was so pretty, she said, and would help him to cut beautiful teeth.’