He had no exact idea of how much diamonds were worth, although he had heard that if they were monstrously large, as this one was, they could no longer be valued carat for carat: that would put them beyond the reach of even the world’s richest men. But even at auction, this diamond would have to be valued at hundreds of thousands of pounds, perhaps millions.

‘I’m a millionaire,’ he thought to himself. It was like emerging from a wine-cellar into the open air and discovering that he was drunk.

He had no doubt at all that the stone was real. He remembered as he turned it around and around in his fingers what his mother had whispered to him only five weekends ago on the wisteria-wrapped veranda of the Reverend Ponsford’s house at Herne Hill, when everybody else had been playing croquet on the sun-blinded lawns.

‘Your father made sure you were taken care of,’ she had said. ‘Your real father, that is. He provided for you, and for your children, but secretly; so that when I go, you shall never want.’

‘You’re not going to go,’ he had smiled at her, and taken her hand between his. In its white summer glove, it had felt like a dead starling, all bones and feathers.

But whether she had experienced a premonition or not, a kind of Tarot-reading from the weather, and the clouds, and the postures of the reverend gentlemen who were playing croquet, she had gone, within three weeks of the croquet party, of a summer cold that turned to pneumonia. At the age of thirty-three, Peter Ransome found himself to be an orphan.

The effect had caught him off-balance. He had not been prepared for the abrupt loneliness of it; nor for the pain that he would suffer as he tidied up his mother’s affairs with Messrs Winchell & Golightly, Solicitors and Commissioners for Oaths, of Croydon; and as he cleared up his mother’s house in Kennington, in South London, not far from the Oval cricket ground. As he came across photographs and memorabilia from his mother’s past: a sepia print of his stepfather with the Bishop of Woolwich, another of his mother arm-in-arm in some scrubby landscape with Cecil Rhodes, a lion’s-tooth necklet, a silver snuffbox with an embossed view of Victoria Falls, he began to feel as if he no longer knew who he was, or why he was here. He had inherited all of these fragments from other people’s lives, but there was no longer anybody in the whole world to whom he was directly related.

His stepfather, the Reverend Hugh Ransome, had died of a seizure the day before Queen Victoria’s Jubilee celebrations, on 21 June 1897. The excitement of arranging a party for Kennington’s children and old folks had been too much for him: that, and the heat.