'Why?' I asked, puzzled at his suggestions. And then, quickly, in case he should take that as an indication that I would: 'I'm sorry, Sir Clinton. But I'm leaving tomorrow for-'

He held up his hand. 'Listen to me first, Gansert,' he said. 'You're no longer connected with B.M. & I. - I know that. But you can't give eight years of your life to a concern without something of it sticking to you. Those thorite alloys, for instance. You started that. They were developed as a result of your efforts. And if we could get into full production-'

'That's a pipe dream,' I told him. 'And you know it. Thorite costs dollars. And even if you'd got all the dollars in the world, there just isn't enough of the stuff. American output is negligible, and that's the only known source.'

'Is it?' He fished a small wooden box from the pocket of his overcoat and pushed it across the table at me. Then what's this?' he asked.

I lifted the lid. Inside, resting on cotton wool, was a lump of metallic-looking ore. I lifted it out and with sudden excitement took it over to the window. 'Where did you get this?' I asked.

'First, what is it?' he asked.

'I can't be certain until tests have been made,' I told him. 'But I'd say it's thorite.'

He nodded. 'It is thorite,' he said. 'We've been through all the tests.'

I looked out of the window at the smoke and dirt of London's river. I was thinking of long assembly lines pouring out thorite alloy equipment, stronger than steel, lighter than aluminium, rustless and bright. If we could mine thorite in quantity then Britain would no longer lose ground to America. 'Where was this mined?' I asked.

He sat back in his chair again. 'That's what I don't know,' he said.