He looked at me cautiously and didn't answer.

'I'm being serious,' I assured him. 'I need to learn about money.'

He remained silent.

'Can I walk with you a little?'

He nodded and we went out together. He was a curious sight. Mrs Morrison had stitched him a large, stiff canvas bag to contain his top hat, which might have been blown off or become soiled as he cycled, and this he tied carefully to the back of his machine. Then he began to pull on two cloth leggings, which he tied around ankle and thigh to protect his trousers, and a form of scarf which went around his neck to defend his stiff white collar against the filth of the London streets.

'You do know that you look ridiculous in all that?'

'Yes,' he said equably, speaking for the first time. 'But my employers are sticklers for appearance. Many a lad has been sent home without pay for not being properly turned out. What do you want to know about money for? I thought you disapproved of it.'

Franklin had once heard me discoursing on the evils of capitalism, but had not seen fit to defend his god against the heresies I spoke.

'Have you heard of someone called Lord Ravenscliff?'

Instantly I could see a look of mingled surprise and curiosity pass over his face.

'I have been asked to write his biography. But I've been told that his life was money. Or that money was his life. One or the other.'

'Why on earth would anybody ask you . . . ?'

I was getting heartily sick of that question. 'I have no idea,' I said testily, 'but his widow decided I was the right person and is paying me for the job. I will happily pass some of my good fortune on to you if you will allow me to use you as a sort of reference dictionary for anything I do not understand. Which is nearly everything.'

He considered this. 'Very well,' he said briefly. 'I will happily oblige, when I have time. I will be free this evening after dinner, if you wish to begin then. What sort of thing do you want to know?'

'Everything. I mean, I know what a share is, more or less. But that's about it. It's not as if I have any money myself, so it's never been of much interest to me. Just a moment.'

I ran back inside and up to my room, grabbed the file from Seyd's and went back outside to the pavement. 'Here,' I said, thrusting it into Franklin's hand. 'This is meant to be a summary of Ravenscliff's business. Could you tell me what it's all about this evening?'

He stuffed it into the bag, along with his top hat and his white gloves, and pedalled off.

I went in to confront Mrs Morrison's bacon and open the post. I rarely got letters of any sort, so the envelope which awaited me, propped up against the toast rack, held an obvious interest, as it was thick, made of heavy cream paper and addressed in a flowery hand. London W was the postmark, and it evidently fascinated Mrs Morrison as well, as she referred to it as she poured my tea, made mention again as she brought me my plate and hovered with excitement as she waited for me to open it.

I could see no reason to deny her the pleasure, so opened it with a flourish using the butter knife as a letter opener. It was from a Mr Theodore Xanthos, of the Ritz Hotel, who referred to having met me the previous day. Careful thought suggested this must be the little elf I had encountered in Bartoli's office. He said that, as he had known Lord Ravenscliff for many years, he might be of assistance in my work, and would be glad to help if he could. As he travelled a great deal on business, he was not often in London, but if I wished to come to his hotel before next Friday, then he would be most pleased to talk to me.

That was useful. It was pleasant to think that someone wanted to help. I tucked the letter in my coat pocket, finished my breakfast, thanked Mrs Morrison fervently for the excellent repast, and walked out into the cool morning sun.

Until that evening the day passed uneventfully. I went to Sloane Square, where I knew there was a bank, and asked to open an account. The Midland and County (a joint stock bank, I learned, as opposed to a private bank – these things become important when you study them) seemed quite enthusiastic when I mentioned the regular payments of £6 14s 8d that would be credited to my account every week. They were not so enthusiastic when I informed them that in fact I had absolutely nothing to give them at that moment, but dealt with the disappointment in a manly fashion. They gave me a book of cheques, with strict instructions not even to think of using one until I had deposited some money.

I went then to the Chelsea library to plunge into the world of money. Banking – joint stock, private, discount. Bills of exchange. Bills on London for forward delivery. Consols. Debentures. Issue at, below or above par. Yield. Dividend. First preference (or second preference) shares. Bonds, international, domestic, government or commercial. Clearly this capitalism was a more sophisticated beast than I had thought. I had considered it to be a means of theft that was more or less magical in its operation, but slowly realised it had its rules. Arcane and incomprehensible they might be, but rules nonetheless. Some people, at least, understood how it all worked. And what they could understand I could understand as well.

This determination was the sole result of my morning in the library. That and a headache, and the information that Mr Theodore Xanthos was, alas, only a salesman working for Ravenscliff's shipbuilding company. A pity. I had hoped he would have been more important than that, but it seemed he was only a minor figure whose enthusiasm to assist came from a desire for a mention in a book which would never get written anyway.

I walked down to the World's End for a sandwich and a pint, and returned to easier, more familiar matters in the afternoon. The death of Lord Ravenscliff. The obituaries. Journalism. Things I could grasp standing on my head. McEwen said start at the end and work back, and it was good advice, even without his own particular interest. I needed to know and understand the man; and a man's death is often very illuminating.

I summoned the papers – The Times and the Telegraph, as well as the financial papers as they always report on their own more fully – and read until my eyes popped out of my head and the library closed. I learned a little, but very far from enough.

The death first. Here the newspapers were singularly uninformative. Lord Ravenscliff had been discovered by a passer-by lying on the ground outside his house at two in the morning of 27 March 1909. He was still alive, but had died soon after. Death was due to head injuries sustained from a fall from a second-floor window. It was believed he had tripped on a carpet. He was sixty-eight years old.

The details were much as his wife and McEwen had related, and gave little else besides. The similarity between the various reports was striking. Evidently not a single one of the reporters had written the account himself. They all had a common source, who must have more or less dictated the report. More than that, the brief summary of events appeared in all the papers some three days after the death – that is on 30 March, an unusual delay in reporting the sudden and violent death of a peer, even if one of recent creation. Ordinarily events would have proceeded thus: Ravenscliff found, police summoned. Police go back to their station to report, man on desk informs journalist, who comes in for routine enquiries, as one does every morning. If it is not the stuff of which great scoops are made (and this would not have been considered such), he informs his colleagues in the pub at about eleven. All make whatever enquiries they see fit, and the first account appears in the evening, the rest the next morning.