If the love between his mother and his real father had been only half as fierce as his mother had described it (and being a modest woman, a vicar’s widow, it had probably been twice as passionate, and twice as jealous as she had told him), then this diamond which symbolised it just had to be authentic, and flawless, too.

His mother’s maid, Olive, came into the bedroom, with a japanned carpet sweeper, her hair a chaos of henna-stained curls and tortoise-shell combs. ‘It wouldn’t be disrespectful to open the curtains, do you think, sir?’ she suggested. ‘I would hate to think of you straining your eyes. My ’enry strained his eyes, fighting in the dark at Nicholson’s Nek.’

Peter clasped the diamond protectively in both hands, and turned around in a way that was stiffer and more mannered than he would have liked. ‘By all means draw them,’ he said. ‘I don’t think Mother would have wanted to see the house so gloomy in any case, do you?’

Olive drew back the thick brocade drapes with a rattle of brass rings. The London sunlight fell across the patterned rug, and on to the white-covered bed on which only a fortnight ago his mother had closed her eyes for the last time, as if asleep. On the wall beside the bed hung a plain wooden crucifix: his mother used to tell Peter that she had been given it by a missionary in South Africa, when she was still a young girl — before she could even speak English.

‘You’d like some tea, sir?’ enquired Olive.

Peter kept his hands clasped tight together. ‘Yes, tea,’ he said. ‘I shall be down directly.’

‘Very good, sir.’

When Olive had gone, he left the dressing-table and walked across to the oval cheval-glass by the window. In it, he saw a dark, shy-looking young man in a plainly-tailored grey suit; a young man whose complexion was too dusky to be English, and yet whose short straight nose and sharply-defined forehead were too European to be those of a pure-blooded African. Racially, he was a thrice-cut cake: a third Dutch, a third Hottentot, and a third German-Jewish.

He was used to the difficulties of having tinted skin. He was an automobile mechanic, working for the Vulcan motor car company in Southport, Cheshire, but he knew that for all of his talent with a spanner he would never make chief engineer. He raced, too, a little, whenever there was a spare 10-hp car and enough ethyl. But he would never be allowed to make the grade as a first-class driver. This was an England which tolerated half-castes as the inevitable outcome of a far-flung colonial empire, but which scarcely ever admitted a ‘fuzzy-wuzzy’ to the inner circles of society.