Garth Steinman puffed out his cheeks. ‘It depends on its history. If Mr Ransome here can establish that it is rightfully his, then we can make some enquiries right away, of dealers and collectors, and of royal courts, and we may be lucky enough to be able to close a private sale, which usually fetches more than an open auction. The market price is quite steady at the moment — so we may get three to four millions, if we play things right. I’d expect a commission, of course, of thirty per cent.’

‘That seems excessive,’ said Peter.

Garth Steinman smiled tightly. ‘Seventy per cent of three millions, which is what you’ll be left with, is rather more than seventy per cent of nothing. There aren’t many men on earth who can sell this diamond for you, I assure you. Well — you must know that, or you wouldn’t have brought it here to begin with.’

‘He’s right, Peter,’ said Samuel.

Peter thought for a moment, and then nodded. ‘Very well, Mr Steinman, I’ll leave the sale to you. I shall require a receipt, of course, to the effect that you’re holding the diamond. And I shall also require you to seek my approval before you close the sale.’

‘Naturally,’ said Garth Steinman. ‘Can I offer you a brandy?’

It was more than a month before Peter heard from Garth Steinman again. Then, when he was back at the Vulcan motor works at Southport, on a sullen August day, he received a telegram saying, ‘Entrain for London at once. I have a sale — Steinman.’ He told his chief engineer that he was feeling sick, and took an omnibus back to his small walk-up flat on the outskirts of Southport to pack, hurriedly, a portmanteau. By tea-time, his train was pulling out of Northampton on its way to London, and the first flickers of lightning were lighting up the eastern horizon, over towards the flatlands of East Anglia. He arrived in St John’s Wood at six.

Garth Steinman met him at the door. This time, Steinman was dressed in a consummately-tailored afternoon suit, with a wing collar, which gave his head the appearance of a pale Christmas pudding on a white dish.

‘You’ve been remarkably prompt,’ he said, and showed Peter inside. ‘Do you like nudes?’ he asked, as they passed the fountain in the hallway.

Peter glanced at him. ‘In moderation,’ he replied. ‘There’s a time and a place for everything.’

Garth Steinman cackled out loud. ‘I like your style, Mr Ransome. But then a man of your potential wealth can afford to have style.’

They went through to the library. There was no sign of the blonde girl who had been there before. Instead, by the window, smoking a cigar, stood a broad-shouldered man of about fifty, wearing a black tailcoat and striped trousers. He had a permanently amused expression on his ape-like face, and a very bushy moustache.