He glanced around him, somewhat in the way you might if you felt your employer could be hovering nearby, watching and listening.

'Come and take a little stroll,' I said. 'I do not think there is anyone who will see you talking to me. And I will never reveal anything at all. Word of a journalist, if you doubt my honour.'

He sighed heavily, and gave in. The surrender was complete, and I could see that he would now tell me anything I asked him. My opinion of him was not high. I would have thought better of him had he tried to run, or hit me first.

'So, let's begin. The Argentinian loan. Why is your bank not participating? Was that your decision?'

'Oh no. Not me. I am not sufficiently senior to decide a thing like that. I would never dare defy Barings on my own authority. I arrange the practicalities of taking up a subscription, I do not decide what we subscribe to.'

'So? Who does decide?'

'Normally there is a committee which evaluates each issue. In this case, it was a decision taken by the Chairman alone.'

'And that is unusual?'

'That is unheard of.'

'How did it happen?'

He looked around, nervously once more. 'I was told to write a letter refusing to take part. And also instructed to give no reasons why this decision had been taken. Again, this is unusual. It is normally a matter of courtesy to give an explanation, even if it is informal.'

'And, again, it was the Chairman who gave you these instructions?'

'Yes. He summoned me personally. I asked why, as in the past Barings' business has been very profitable. All he said was that this time no one was going to take part. Not a single institution in France was going to touch it.'

'Why not?'

'Exactly what I asked. Was there something wrong with it? I asked. But no, he said there was nothing particularly wrong with it. That was why Barings was going to get such a shock. And more than Barings, he said.'

'And what did he mean by that?'

'He said no more. But it puzzled me, as I can see it puzzles you. So I listened, you see, and asked questions of my colleagues at other banks. And do you know what I discovered?'

He was positively voluble now, willing to tell me things I hadn't even asked.

'I've no idea.'

'It was true. All the big banks in France will refuse to take any Barings paper. Not only that, I know of two banks in Belgium, and one in Russia, which will also turn it down.'

'How much is this issue?'

'In all, about five million pounds. A very great deal of money, but no more than many South American issues and with better prospects than many. Of course, you can argue that too much money has been put into Argentina, and I would sympathise with that view. Sooner or later the markets will have had enough. But if you want to reduce your liability, then this is a foolish way of going about it.'

'Why so?' I knew the answer to that already, but also knew that the more he told me, the more he would tell me. He hadn't even noticed I wasn't taking any notes.

'Because we hold a substantial amount of South American bonds, and our customers have bought more off us. A failure could panic the whole sector and drive down prices across the board. We could lose a great deal of money. It would be much more sensible to sell off stock first.'

'And that has not been done?'

'There has been some selling, but not enough.'

If South American bonds collapsed, then French institutions would lose money, that was true. But nowhere near as much as English ones would lose. Of all the bonds sold in the past decade, since Barings discovered South America, at least half the value had been sold in England, the rest had to be spread across Europe and North America. I could not call the figures to mind, although it was obvious that it would send a shockwave through the markets. But nothing that the City could not cope with. The American railroad collapse had been just as severe, but had been surmounted without much difficulty. And the effect would run right the way across the Continent. Why would banks connive at conjuring up losses unnecessarily? As M. Hubert said, there were much more sensible ways of getting out of markets you feared might be nearing their peak. Bringing them down while you were still fully exposed was foolish, to say the least.

But he could tell me no more. He confined his interests to bond issues, horses and his lover. He could give no reasons, nor offer any guesses. His was not a speculative mind. I ended up quite admiring him for his little peccadilloes. It showed that he was not entirely an automaton. Somewhere in him there was a little imp, urging him to transgress and, after many years, he had given in. I hoped very much he was enjoying himself, because he was not very good at it. Sooner or later, he would be discovered and his world would crash in ruins.

'Thank you,' I said when it was clear I had exhausted his knowledge. 'You see, you have told me nothing that was so very dangerous. It is a small sin in comparison to your others. And will remain very much more secret than they will.'

'What do you mean?' he asked, apprehensively.

'Simply that what I could find out fairly easily, then so others can.

And will.'

I bowed to him, and left, leaving him standing, watching me. I am glad to say – what a strange world of amorality I had come to inhabit! – that M. Hubert acted on my warning. I never got the full details, but it appears that he set about using his very considerable talents to embezzle a good deal more money over the next year. When the bank finally discovered that the accounts were not quite what they should be, M. Hubert went to Buenos Aires, and vanished for ever.

I had a great deal of puzzling to do, and I think best when I am walking. So I walked back across the Bois de Boulogne to Paris, and walked still further, through the rough houses and ever-shrinking fields which were still a part of the far west of the city then, before resting in a café. There I sat, surrounded by laughter and smoke, as I pondered what M. Hubert had told me. Clearly, I would have to inform Barings. From what he had said, the bank might know that this issue was going to be tricky, but would not yet know the full extent of the difficulties that were coming their way.

But I still could not make sense of it. These banks seemed to be acting in concert, but they were behaving like rank amateurs; almost as if they wanted to throw their money away. If, for a moment, you conceded they were not total fools (which is occasionally tempting with bankers, but rarely with the most senior ones) then there must be a reason. But what might it be? Barings issues a bond, half of which is taken up in England, leaving them with two and a half million sterling to place on foreign markets. Some of it would go, no doubt. So, assume that there is a shortfall of two million. A vast sum of money and it would cause difficulties, as Barings obviously could not cover that from its own resources. But such things had happened before, even if not quite on that scale. At the last resort there was the Bank of England, which would advance Barings the bullion from its reserves. Barings would have to pay through the nose, no doubt, but it would survive. Its reputation for canny manoeuvres would be dented, but its titanic strength would be demonstrated for all the world to see. The only result would be that everyone would have lost a great deal of money. What was the point of that?

Two large glasses of beer brought me no closer to an answer, so I resumed my walk. I enjoyed it; that part of Paris which has the Avenue de la Grande Armée running through it has become much drearier in the past decade or so. Then it was a very peculiar quarter, with great apartment blocks rising up out of nothing, with perhaps a field full of cows to provide the city with milk on one side and a mason's yard or some other small workshop on the other. Tall buildings, six floors high, snuggled up to one-storey workers' hovels which had not yet been swept away by property developers. One patch of barren land was occupied by a gypsy encampment, another by an open-air music hall, in between a fashionable, and spectacularly ugly, church, which looked forlorn and abandoned even though it was brand new.