The Stock Exchange daily bulletins are the dreariest of all newspapers; the prices for dozens of government stocks, the prices of innumerable foreign stocks and utilities. The discount rates and interest rates applicable to hundreds of different instruments, in dozens of countries. News of new issues and dividend payments. By carefully considering all of these, a man of sense can make his fortune. So it is said; it was my great weakness as a banker that I never had the slightest interest in any of it. I had forced myself to understand it, but it never brought me the pleasure or satisfaction that it gave to many of my colleagues.

I tortured myself reading columns of numbers and prices and rates, hoping to find some hint of how the second stage of this adventure was going to play out. For there must be a second stage. M. Hubert was right: why do something which could scarcely hurt Barings, and could cost you a lot of money? But if banks across the Continent were indeed co-ordinating a response, something serious was taking place and it could be assumed that it was being organised by people of intelligence.

It took the better part of two hours, but then I had it. And even I was shocked. I had assumed I would find some sort of evidence of a secondary assault on Barings, but in fact it was much more serious than that. So much so that I didn't even look at the relevant figures until late; it never occurred to me it would be important.

Barings wasn't the target. They were aiming at the Bank of England itself.

The figures were clear, once I had noticed them. For the past two months, bullion had been draining out of the Bank. Money was withdrawn, new deposits were not made, or were delayed. The Bank of France, citing the need for gold to pay for a tax shortfall due to a poor harvest, had postponed depositing ten million sterling; the Bank of Russia had withdrawn fifteen million. Commercial banks which ordinarily would keep smaller but substantial quantities of gold on deposit in London had been pulling it out: £100,000 here, £200,000 there. In all – I settled down with pencil and paper and added it up going back six weeks – another seven million had been withdrawn in this way. According to my calculations, the Bank had probably less than four million in bullion in its vaults.

And next week, the most powerful bank in the world was going to get a shock which would send it reeling, causing panic throughout the London markets. When people panic, they want their money back. They want gold. And Barings would be wanting to borrow the same gold, to cover the holes in its positions. It had promised the Argentinian Water Company five million. It had to pay, and it wasn't going to have enough money. Every stock listed on the Exchange would plummet in value. Banks and their customers would panic. A queue of bankers would form at the Bank of England and it wouldn't have enough gold to satisfy demand. It would have to suspend convertibility, say it would no longer give gold for paper, and the reputation of the entire City of London would be in ruins, with Barings the first to fold. 'I promise to pay the bearer on demand the sum of one pound.' On demand. In gold. Except that it would be revealed as a lie. Not worth the paper it was printed on, so that paper would rapidly become worthless.

It was breathtakingly audacious. And simple. And it was going to work. 'A determined enemy would not waste his time and gold striking at the navy or invading the colonies. He would aim to destroy belief in the word of a handful of bankers in London.' That was what Netscher had said, and he was right. It was going to happen. And that idiot Felstead wouldn't believe me.

The beauty of the scheme was that even telling someone would merely start the panic earlier, rather calm it down. There was not enough gold in London, and nothing could change that.

I came to the conclusion that, even though it might already be too late, I must, at least, alert Mr Wilkinson, and for that I needed the assistance of John Stone. The Times could not help me, as we ordinarily sent our stories by the public telegraph, going down to the local post office and sending them off, word by word. This was not very private, and it was well known that the operators of the machines received a small stipend from the police to report anything of interest. Felstead would not help, but Stone certainly would, I thought. And I knew that his companies maintained their own private telegraph links, which might, perhaps, be intercepted but which were more likely to pass undetected.

Finding Stone, however, was not so simple. I knew that he had offices close to the Palais Royal, but these were closed – it was already so late that I went there just to be thorough, rather than with any real hope of success. I knew, also, that he stayed usually at the Hôtel du Louvre, but again he was out. It took a hefty inducement before I was allowed to go up and talk to his manservant.

'I'm afraid I do not know where Mr Stone is, sir,' said this character, his face immobile as he looked me straight in the eye.

'Yes, you do,' I replied tartly. 'And however commendable your lying may be under normal circumstances, it is not now. I have to see him, and as swiftly as possible. It is a matter of the highest urgency, and he will not thank you if you do not tell me where to find him.'

The servant hesitated for a few seconds, then said, with the greatest reluctance, 'I believe he had an appointment for tea with the Countess von Futak. But I do not know where that might be . . .'

I grinned broadly at him. 'But I do. Excellent man, thank you. I will make sure he is aware of your impeccable judgement.'

I didn't quite run down the stairs, but I hurried, and I certainly pushed aside an old gentleman waiting to be handed into a cab outside the main door. He scowled, I made an apologetic gesture as I leaped in and gave directions.

It took fifteen minutes to get to Elizabeth's house, and I battered on the door until I was let in and demanded to see both her and Stone. It then occurred to me that I might well be placing both of them in a position of considerable embarrassment. Elizabeth had told me that she was open to visitors only on certain days and at certain hours. For the rest she had her business to attend to. This was not an evening when she received anyone other than her shareholders. Did that mean that Stone had acquired a stake? Oddly, as I waited, I hoped very much not. But I did not have time to wonder why it mattered to me.

There was no embarrassment, fortunately. I was shown into the little salon, the one she kept for herself, rather than visitors, a charming room furnished to her tastes, not to the requirements of show. And there they were, sitting in two little chairs, side by side, just like couple spending a few intimate moments together, talking about their day and enjoying each others' company. The difference in her struck me immediately; she was relaxed, unguarded, and completely at ease. I didn't think I had ever seen her quite like that before. Certainly she was never so when with me. Always I sensed a tension, as though she expected to have to defend herself. I felt jealous, although it did not hit me at the time.

But the moment I entered that watchfulness came back, and Stone rose to greet me and break up all impression of intimacy.

'Forgive me, both,' I said. 'I would not be here uninvited if it was not a matter of importance. Mr Stone; may I have a word in private, please.'

Elizabeth rose. 'Stay here; I have matters to attend to upstairs. I will not disturb you.'

She left the room swiftly, and Stone eyed me with a mixture of curiosity and, I could tell, no small amount of annoyance.

'As I say, I apologise. However, I need to send a telegram to Wilkinson which will not be read by anyone else. I would like to use your telegraph system.'