‘There’s currency of different sorts in there,’ he said. ‘At most airfields we can operate on credit, but at some of the smaller ones – particularly in South America – we have to pay cash for gas, servicing and airfield charges. Sometimes Mr Salton wasn’t aboard, so he gave me the combination.’

That sounded reasonable. I dug into the safe and produced several sheafs of foreign currency – American dollars, Brazilian cruzeiros, Ecuadorian sucres, Bolivian pesos, Peruvian soles and so on. It was quite a wad, even if it did look like Monopoly money. There were no Campanillan pounds but then those wouldn’t be needed.

There were several objects in protective wallets: two cigarette lighters, one of gold and the other of what appeared to be stainless steel but was probably platinum, and two cigarette cases likewise. Four sets of cufflinks and four tiepins, two signet rings and an American silver dollar with a hole bored through it – a good luck piece?

Nothing else.

I put it all back then looked at Haslam. ‘Was all this stuff here when you took the plane back to the manufacturer?’

The expression on his face was a mixture of shock and surprise. ‘You know, no one even thought of it. Mr Salton didn’t mention it and it never occurred to me.’ He smiled ruefully. ‘I guess we’ve got to thinking of it as part of the standard equipment of the airplane – like the radio, say. Mr Salton’s clothes weren’t taken off, either.’

‘But the alcohol was,’ I said.

Haslam shrugged. ‘The galley is cleaned out as a matter of course after every flight.’

When I stopped to think about the kind of man I was investigating, it all sounded completely logical. The very rich are not just folks like the rest of us. One of the super-rich once said in surprise, ‘You know, a man with five million dollars can live just as though he were a rich man.’ That’s pretty high-level philosophy.

‘Anything else, Mr Kemp?’

‘No,’ I said. ‘Not for the moment.’

Haslam went forward to join Philips in the cockpit or the flight deck or whatever fancy name they give it in planes that size. I sat down and began to go through drawers. I didn’t really expect to find anything, but old habits die hard. There’s a curious fascination about going through a man’s effects, delving into the minutiae of his life – not that there was much to find about Salton because the cupboard was bare apart from blank stationery, office knick-knacks and the like. Everything personal had been cleared out, presumably by the efficient Mrs Forsyth.

Presently the plane began to move. We taxied up the runway and then turned. A loudspeaker over my head crackled and Haslam said, ‘Fasten your seatbelt, Mr Kemp.’