Budapest is, of course, really not one city at all, but two. Unlike Vienna, which has hidden the Danube away in a culvert on its fringes, Budapest allows the great river – brown, wide, and fast-flowing by now, as it floods on southward and eastward – to surge through its middle, dividing it into two refracting capitals, looped together by great bridges, which stare across its waters at each other. High old Buda looks down from its hilltops onto flat nineteenth-century Pest; lowdown Pest stares up at the castle, the battlements, the double hills and deep valleys of ancient Buda. But when my taxi reached the hotel that Lavinia had booked for me that morning back in Vienna, I discovered that I was staying in neither of these places. My hotel lay in the very centre of the river, on Margaret Island, reached by a zigzag bridge, a quiet green corner that made an excellent resort for lovers and joggers, summer walkers and playing children, and no doubt, in the older, darker times just behind us, colluding spies and conspirators.

Back in the days of the Dual Monarchy and the belle époque, the tired and sated aristocrats of middle Europe had, I gathered, come here to its great Grand Hotel for the famous hot sulphur baths, hoping to purge away their old amorous and gastronomic excesses and at the same rime start on new ones. Rumour has it that Franz Schubert was made better here, though we can take it that Franz Kafka was made a good deal worse. Then, in the new postwar order of things, it was Party bosses and members of the nomenklatura, small government officials and workers for the post office, Russian tourists and East German attaches, who came to put on the grotesque rubber bathing-caps, splash in its fountains, take in its sulphurous steam, roll in its mud. Now the Grand Hotel was not so grand, though it retained its shape and dignity. With the twists and turns of recent history, it has taken on another incarnation, and been quite heavily restored. Today it is the Ramada Inn, and stressed German executives and excited American tourists now enjoy the pleasures of its stinking sulphur and eternal mud.

I checked in and got my key in the hotel’s now smart lobby, and changed Austrian schillings for Hungarian forints. Then a slow sad elevator took me upstairs to the long, many-bedroomed corridor, smelling of sulphur and chlorine, on which I hunted for my room. I found it at the very end, one of the smaller suites; even at the former Grand Hotel of Budapest, Lavinia had done all she could to make sure I had not ended up in total luxury. Nonetheless it had a tiny balcony, a view over the fast-flowing Danube, and an enchanting misty glimpse of fairytale battlements on the hillside above. I could not complain. I unpacked a little, sat down at the desk, picked up the telephone, and called the number of Sandor Hollo, which Gerstenbacker had given me. There was a dull dragging sound, then a crackling answer-phone message in Hungarian, one of the world’s most obscure languages, with the exception of African Click, then a quick flourish of Bartok, then the dragging sound resumed.

I tried for most of the afternoon. From what Gerstenbacker had told me, I had assumed that Sandor Hollo was a teacher of philosophy at the university, and so I imagined that he was even now closeted with his students, lecturing to his classes, sitting over books in the university library, or doing whatever university teachers do if they are not Professor Otto Codicil. Still, I kept on trying, on the half-hour, until I saw that November darkness had begun to fall over the river, and bright floodlights were now picking out the battlements and buildings on the high Buda bank. So now I gave up, made my way downstairs, and went over to the hotel bar for a drink. Here, on the barstools, I found myself surrounded by a group of Hungarian beauties, all of them wearing mini-dresses and leather boots that came up over their knees. They sat with their drinks and eyed me with the greatest curiosity. I quickly finished my beer, and went over to the maître d’ at the entrance to the dining-room, to ask for a table for dinner.

The maître checked a plan that lay in front of him on his lectern-like desk. ‘I suppose you are with a film, sir, yes?’ he asked me. ‘Well, I am, that’s right,’ I said. ‘Ah,’ he said, ‘Well, sir, tonight we have BBC making Ashenden, Granada TV making Maigret, Channel 4 making a series on the European Community I think is very good. Which one, sir?’ ‘Oh, none of those,’ I said, ‘I’m here on my own.’ ‘Really it is too bad,’ said one of the Hungarian beauties, who had wandered across from the bar with her Campari soda and was now standing by my side, ‘It is not good to be all alone. If you like it and have twenty dollar I will have dinner with you.’ ‘A table for two, sir?’ asked the maître d’, looking at me with an air of deep human understanding. ‘No, thank you,’ I said, ‘Actually I quite like being on my own.’ ‘You don’t?’ cried the Hungarian beauty, ‘It is too bad to be all alone. Everyone has twenty dollar.’ ‘Well, not tonight,’ I said, ‘Tonight I have some work to do.’ ‘Oh, work to do,’ said the girl, ‘What a pity, well, tomorrow, when you have plenty dollar. You should not be alone, it is not nice. Remember, you can find me here any time.’

That night I slept very peacefully (and also entirely singly) in my bed somewhere in the middle of the great River Danube. In the morning I woke early, and looked out of my window. There were sweatsuited joggers already jogging on the tracks outside, towelled bathers already on their way to their sulphurous pleasures. Fishermen fished, birds dipped and darted, long low Russian cruiseboats slid by on the river, to-ing and fro-ing between here and the Black Sea. I picked up the telephone and dialled my number again, and this time someone answered: ‘Hollo Sandor.’ ‘I believe you can help me,’ I said. ‘Yes, I think so,’ he said. ‘I haven’t explained what it is yet,’ I said. ‘No, but I can help you,’ said Hollo Sandor. A little mystified, I explained that I was a British television film-maker working on the subject of Bazlo Criminale, and that I should like to consult him. ‘A film?’ he said, ‘Everyone makes a film in Budapest now. We are so cheap, of course. Now we are Paris, now we are Moscow, now we are Nice, now we are London, now we are Sydney, Australia. Never of course Budapest, I think they make films about Budapest in Prague. Very well, you like us to meet about your film?’ ‘If you can give me the time,’ I said, ‘I imagine you’re very busy.’

‘For you I find the time,’ Hollo said, ‘Let us meet at noon at the Petofi statue on the Danube prospect. He is our great poet, you know, so everyone will tell you where it is. By the way, you are on expenses?’ ‘Yes, I am,’ I said. ‘Good,’ he said, ‘Then I think we will go somewhere very nice. I know all the places. I will see you at Petofi.’ I went down to the lobby for breakfast, and found there young men from several different and competing film teams, who were packing into vans and trailers the actors and extras, the clapperboards and cameras, the blondes and redheads, that even I knew were the stuff of a television shoot. I imagined our own team coming out to do the same in a few weeks or months. Our Criminale project was not at all unusual. As Hollo had said, these days everyone was shooting films in Budapest.

When I had taken breakfast, I caught the tram into Pest, and found myself walking round a city where, it was very clear, history had been changing very fast. Almost all the street names seemed to have been struck out with red lines, and new names set up either above or below. Karl Marx Square, where I got off the tram, was evidently no longer Karl Marx Square. 1 did, though, discover one more enduring monument. Here in the square was Gustave Eiffel’s splendid little West railway station, as fine as I had hoped. I had not come into it because its trains went east, into the Puszta and to Transylvanian mystery. It was probably from here that Bram Stoker’s innocent Jonathan Harker started, when he chose to take his unfortunate summer holiday in the land of Vlad the Impaler, in the book whose hundredth anniversary was due, like so much else, very shortly. What he would not have seen in those days was the new addition that had been made to the building. Tucked onto Eiffel’s station was the emporium of McDonald’s Hamburgers, a handy meat dish that might have saved Count Dracula a lot of trouble.