‘No,’ replied Samuel. ‘But it could be topaz, or strass, which is high-density lead glass, or even quartz; although I doubt that it’s quartz, because it appears too brilliant.’

Peter was silent for a moment, watching his friend examine the stone through his loupe, but then he said, ‘I have to tell you something which may make you change your opinion.’

‘Well, do,’ said Samuel, ‘because if this is a real diamond, then you’re in the money for the rest of your life, and I’m not joking.’

‘The Reverend Ransome wasn’t my real father,’ said Peter. ‘I know that I always pretended he was, when I was at school, but that was only because I was embarrassed about it. My real father was Barney Blitz.’

Samuel put down the diamond and looked at his schoolfriend in astonishment. ‘Now, you’re really having me on toast. This is just a practical joke, isn’t it? You’re going to go back to all the fellows at Kennington and tell them how Samuel Kellogg thought a piece of glass from a Christmas cracker was worth millions of pounds.’

‘Samuel, I’m telling you the truth. I swear it. When my mother was in South Africa, she lived with Barney Blitz for years. He was my real father.’

‘Well, you could knock me down with a feather,’ said Samuel.

Peter pointed to the diamond. ‘That’s why I’m quite sure that the diamond is real. And that’s why I have to know where I can take it to sell it. I don’t want to be sold short. My father gave that stone to my mother so that my future would be secure. I wouldn’t want to let him down by giving it to the first diamond dealer I meet for only a quarter of what it’s worth.’

Samuel looked at the stone for a long time. ‘You’ll excuse me,’ he said, ‘but I’ve never seen a diamond like this before, and I never will again. I want to make sure that I remember this moment. So, Barney Blitz was your father, was he? You could knock me down with a feather.’

‘The point is,’ said Peter, ‘where can I go with such a diamond?’

Samuel laid the diamond carefully back on his workbench. ‘There’s only one man that I know of. Garth Steinman. I don’t know whether you’ve ever heard of him or not, but he’s a dealer in unusual and speciality jewels only. Quite an eccentric, but a very rich eccentric. He acquired the Montfort emeralds for the late Queen. He’s a friend of the Rothschilds, and of J. P. Morgan. He has a house in St John’s Wood, although he may not be there now. He winters in Italy, and spends his summers in Switzerland.’