'I hope that you'll excuse me, sir,' he said, 'but I've already eaten. A particularly painful swelling of the stomach, and a ripping gripe in the bowels, sets in if I eat too late. I'll keep you company, of course. Unless you have already partaken?'

'I made a point of waiting,' I said, my stomach churning on the smell in that enclosed s.p.a.ce.

'Just heating it up for you. Ready in a few minutes. Would you care to view your bedroom before you dine, sir?' he asked, as if certain preliminaries needed to be got out of the way.

Had other lodgers made themselves at home, eaten his onions, then fled as soon as they saw the bed without bothering to pay him?

He pointed to a shimmering grey curtain, which was heavy with grease and smoke, then pulled it aside like a theatre-manager who intended to impress with the scene he would reveal.

'Did you shift out when the French came through?' I asked, staring into the narrow cubicle beyond the curtain. My 'bedroom' was six feet long and four feet wide, a corridor closed off by a barred door, which led, I guessed, to the rear of the house where rubbish could be tipped and chamber-pots emptied. If there was a bedroom upstairs, it was his. I knew such 'lodgings' from my own days at the university in Halle.

'Not for very long,' he said with a hearty chortle. 'This is the bit of Prussia that they didn't want. I'd like to see the rat-holes they are used to in Paris,' he added with a sarcastic French accent on the second syllable.

He stepped into the alcove, and gently ran his hand over the bed. 'These sheets are fresh. Three nights only, as I told you,' he said again, raising the grey pillow-case to his nose, inhaling deeply. 'The lad was most particularly clean. He sat his doctoral tripos the other day. It went off very well.'

He pinged his knuckle against a large ewer which was standing in a matching bowl on top of a hat-box.

'Water for washing and drinking, sir.'

He flicked his nail against a chamber-pot.

'Freshly rinsed,' he said.

I nodded, thinking that I would need to keep my wits about me during the night. I did not wish to drink from the one when I ought to be drinking from the other. There was no lamp or candlestick, which was no bad thing. In such confinement an outbreak of fire and instant immolation was more than probable.

'And now, sir, if you wish to eat, the soup is on the hob.'

We turned around, the curtain fell on the scene of my nocturnal slumbers, and we were in the kitchen again. I sat down at the table where the plate had been set. He pulled up the armchair and sat himself opposite, reaching for the pot and the ladle, carefully filling my bowl to the brim.

'Did the French leave onions behind to pay the rent?' I asked convivially. 'The streets are full of the smell of them.'

'You have a selective nose, Herr Stiffeniis. The French complained of everything else. Our onions are in good supply this year.'

As he spoke, he gestured impatiently to me to eat.

'Delicious!' I lied, spooning up the thin and tasteless gruel. 'And thank you for pointing me towards the Kantstudiensaal today. It has greatly changed, as you remarked. Do you go there often, Herr Doctor Rickert?'

His eyes gleamed fiercely. 'I would if I had the time. Unfortunately . . . Still, I am glad that n.o.ble benefactors have taken the place in hand.'

'n.o.ble?' I queried.

'In a figurative sense,' he replied quickly. 'I've no idea, really. But if that archive were to close, why, it would be as if Kant had died a second time. It had fallen into a terrible state before the French came along and laid another heavy block of granite on Kant's grave.'

'Do you know who pays for it all? The Albertina University does not, as Herr Ludvigssen happened to mention.'

Rickert stared at me, then he winked. 'Good Prussians, sir. Who else?'

'Ludvigssen does not seem to think so,' I replied.

His eyebrows met in a stern frown. 'Is he complaining? I'd like to know what for!'

I broke a piece of black bread. 'The new masters watch him like sharp-eyed, sharp-beaked hawks,' I said. 'He feels threatened by them.'

Rickert's eyes widened. His lips pursed. 'Threatened? They are paying him a decent salary!' he snorted. 'While I'm obliged to rent out rooms to survive . . .' A sickly smile lit up his face. His lips parted, exposing his brown teeth again. 'Of course, sir, it is a great, a very great, pleasure for me to have guests. Guests like you, I mean. Unless we get some students for philosophy, the Albertina will decide to get rid of me next. Then, I'll be obliged to find a sponsor, or take in sailors, soldiers, and the refuse of the taverns. It will be the ruin of me, I can tell you!'

He sank into a fit of sighing depression.

'Did Herr Ludvigssen find a sponsor?' I asked. 'Or did the sponsor find him?'

Rickert closed his eyes, shook his head. 'No idea, sir. No idea at all.'

'Did you manage to find any trace of Vulpius in the lists, as you promised to do?'

Rickert's eyelids flickered rapidly. 'Did you discover nothing at the Kanstudiensaal?'

'Vulpius had been there pretty frequently, but Ludvigssen had no idea where he might be living.'

Dr Rickert put his hands to his head and pulled fiercely at his hair. Blond on the crown of his head, it was dyed as black as coal around his ears. Even Pietists fall prey to vanity, it seemed.

'Goodness me! I thought we'd solved that little problem. That's where I send anyone who, you know, expresses an interest in Professor Kant nowadays.' He pushed his lower lip out in a show of uncertainty. 'But, sir, I made it clear, I think. The . . . the money which you gave me was for pointing you towards the archive.'

'The money which I paid you,' I repeated more severely, 'was to ensure that you searched through the Albertina registers.' If I hoped to get anything out of him, I would need to show the same regard for cash that Dr Narcizus Rickert did.

He poured me a beaker of water like the perfect host.

'I wouldn't like you to feel that money has been squandered, sir,' he murmured. 'I did look, and would have given you my report in time. Vulpius has never been enrolled in the schools of theology or philosophy. Not in the last ten years, at any rate.' He pursed his lips and thought for a moment. 'Still, you really should have found him there at the archive. If he is a true follower of Professor Kant, you'll find him nowhere else. They all go there . . .'

He spread his arms wide, his palms turned up to heaven, like the plaintiffs who sometimes appear before me in the court-house. 'You will remember, sir, the price that we agreed on does not, cannot, guarantee the successful outcome of the research. One can only try. Do one's best, so to speak. What did you particularly want to know about him?'

'His address,' I said.

He rubbed his hands, then asked me: 'Have you ever actually met the man?'

'Never.' I lifted the water to my lips, drained it off, then stared into the thick bottom of the gla.s.s, as if the information might be found there. 'Have you ever met him?'

'Me, sir? Vulpius?' His appeal to me was not so much of surprise, more of alarm. 'Can you believe, Herr Stiffeniis, that I would not have told you everything and straight away?'

There, that was the point. Could I believe what he chose to tell me?

He knew about the recent changes at the Kantstudiensaal. He must have realised that the archive had become a potent symbol of nationalist resistance, the hub and focus of a movement which had found its inspiration in Immanuel Kant. I recalled the concern that General Malaport had expressed regarding the presence of Prussian rebels in Konigsberg. They are everywhere, he had said. To the local French authorities, the archive might seem like little more than a pathetic attachment to a former glory, a long-forgotten library where the books and papers of a deceased Prussian philosopher were kept. It was a small bone that might be thrown to the Prussians without losing any sleep.

But what if the danger was real? What if the Kantstudiensaal was the place where the rebels congregated? And more to the point, what if Vulpius was one of them?

I was shaken from my reverie by the voice of Rickert.

'May I ask, sir, why you are looking for him?'

I hesitated for some moments, then I started to tell him precisely who I was, and exactly why I was looking for Vulpius. That is, I told Dr Rickert what I wanted him to know.

The boot was on the other foot.

Dr Rickert leant back in his seat when I had finished.

'I heard about those bodies that were found beneath the Grunen Brucke bridge,' he murmured thoughtfully. 'It's only a three-minute walk away from here. It was the talk of the town 'til the French hanged a gang of saboteurs who were trying to mine the docks. Five of those men were living right across the street from here. Can you imagine that, sir? By the time the commotion blew over, those poor women had been forgotten. What was it, a couple of months ago? And now you say they think that Vulpius was involved in the murder? A Kantian scholar?'

I did not give him time to collect his thoughts. 'The French suspect him. It is in their interests to blame everything on a Prussian. They've set their sights on Vulpius. But you and I, sir, why, we are Prussians. We know where our duty lies. I have always been a fond admirer of Immanuel Kant.'

On that count, at least, I was only telling half a lie.

'Me, too, sir,' Rickert pitched in enthusiastically.

'Just like Vulpius, a Kantian through and through,' I insisted. 'I must find him and warn him of the danger. And I must do so before the French manage to get their hands on him. That's why, Herr Doctor, it is imperative that you help me to locate him.'

I gave him time to think on my proposal by finishing off his soup. But evidently, Rickert needed more time, placing his own survival in the form of cash earned on one side of the balance, and the life of Vulpius, Prussian nationalist, on the other.

'I may be able to help you find him,' he said at last.

Thinking back on that evening in Rickert's house, I often puzzle over what actually happened. Along with the other things that he offered me-bed, soup, water, conversation-had Rickert set out from the start to feed me privileged information that I would never have unearthed without his help? Was his performance chicanery? An attempt to squeeze more money out of me? Or was it, instead, a form of fear, a sublimation, a means of indirectly providing me with information that he would rather not have told me, and which he would never admit having personally given away?

Then again, was it something of an entirely different nature?

'Do you know Salthenius?' he enquired, his voice low, his head bent close to mine. 'Daniel Lorenz Salthenius.'

The name was familiar.

'I studied at the University of Halle,' I replied. 'Salthenius was once the Professor of Philosophy there. It was long before my own time, of course.'

Doctor Rickert clapped his hands like an excited child. 'Correct! But he was more than a philosopher. Born in Sweden, Salthenius was forced to flee for . . . Well, sir, let's just say that serious allegations were made against him. He found refuge in Halle, where he was converted to Pietism by Philipp Jakob Spener himself. Later on, Salthenius moved to Konigsberg. He taught for many years here at the Albertina University and his lectures were packed, sir. Just imagine those days. All those students looking for bed and board at any price . . .'

His eyes flickered, lost in a dream of endless beds and cauldrons of onion soup.

'I do not see what this has to do with Vulpius,' I reminded him.

Rickert raised his finger. 'One moment, sir, I'll get to it. In 1740, his world was turned upside down. Malicious voices were raised against Salthenius once again. In Sweden, he had been condemned to death. In Konigsberg, they satisfied themselves by removing him from the Albertina. But in the meantime, he had met a young scholar who was just beginning to make his own reputation.' He stopped short, and stared at me. His eyes were two bright, interrogative lamps. 'You know who I'm talking of, do you not? I discovered a note from Immanuel Kant in the university archive, asking whether he might visit Salthenius.'

I did not see where his reminiscences were leading.

'A letter that is not in the Kantstudiensaal,' he clarified, tapping his closed fist against his chest. 'I alone know what Kant asked Salthenius . . .'

'A philosophical problem, I imagine.'

He vigorously shook his head. 'Kant asked Salthenius how to contact Satan!'

It had been a long, frustrating day. I did not have the strength to argue with a madman and I had no intention of resurrecting Kant, or the Devil. I would not go down that road. It is always a problem in Prussia: relax your guard and the Devil leaps out at you as if he is something real and tangible. There, I thought, that's one thing the French will never rob us of: our fascination with the diabolical.

'Why would Kant ask Salthenius about the Devil?' I forced myself to say.

'He fled from Sweden, bringing that terrible knowledge along with him.'

'But Salthenius became a devout Pietist,' I objected. 'I have never heard of a Pietist who worships the Devil.'

'Salthenius was never his familiar,' he protested. 'He never bowed to Satan. He tried to use the power of the Devil for the good of Prussia. For the good of all of us!'

He shook his finger in my face.

'If only we had found the spiritual strength to learn from his teachings! Kant tried, believe me, sir.' Were those tears of pa.s.sion glistening in Rickert's eyes? 'When you came by today, asking about Kant,' he said, 'I took it as a sign. A potent sign, though I did not fully understand it.'

'A sign of what?' I felt unable to withdraw from the delirium of his attack.

'You are looking for Vulpius to save him from an unjust French accusation. Vulpius is a follower of Kant. Kant ignored the false accusations against Salthenius. And you have come to me.'

'But you have told me nothing about Vulpius,' I replied, attempting to shatter the brittle chain of his strange logic.

'Not yet, Herr Procurator Stiffeniis. Not yet.'

He rose suddenly, and went over to a small wooden chest positioned near the fireplace. Dropping down on one knee with a grunt, he raised the lid. The chest was full of papers. There were hundreds of sheets crammed in haphazardly. Some were crushed and bent; others were twisted, folded, ripped. When he closed the lid, and returned to his seat, he was holding a small pewter saucer in one hand, and a bundle of papers in the other. The sheets were shaking as if they had a heart that was tremulously beating of its own accord.

'Here we are, sir,' he muttered, beginning to lay the sheets on the surface of the table one at a time, folding out the pages that were bent, smoothing this one, removing creases, aligning them edge to edge, spreading a second layer over that one, until he had covered the entire surface, like Lotte when she made a sandwich-cake.

Then, he set the pewter plate exactly in the centre of the table.

'Just there,' he murmured to himself. 'That's right.'

I tried to see what was written on the sheets, but it was impossible. The contents seemed to be a jumble of words and symbols scrawled and scribbled by a childlike hand in what might have been red ink. It had turned a dull dark brown. Many of the words and letters had run, or smudged, where ink appeared to have bled into the paper.

'What are these messages?' I asked.

'The words of Satan.' He stared at me hard. 'Salthenius transcribed these messages in his own blood. As the Evil One required him to do.'

Was Rickert totally mad?

He was staring at me from deep within himself. He might have been peering out of some dark cavern. I felt a sudden repugnance for Prussia, and all things Prussian. Wasn't it better-simpler-to deal with someone like les Halles? The Frenchman was driven by a blunt materialism that was uncompromising. His hands were dirty. His concerns were finite. His gantries and pulleys were too large, or too small. They worked, or they did not work. His coq du mer would penetrate the sea-bed, or the sea-bed would repel it, send it back, obliging him to make more trials, more calculations. And when his engineering science had found the answer, the solution was there for all to see.

For an instant, I prayed that France would impose its practicality on Prussia. That Bonaparte's men would cancel out the mult.i.tude of devils that continue to haunt us.

'It all began with this,' said Rickert, waving a flimsy piece of paper in the air. 'It was folded up inside the syllabus that he wrote in 1737. You know the Pietist principle? Bukampf. A man must win his individual struggle with the Devil if he hopes to enter the Kingdom of Heaven. Salthenius had a greater plan: he challenged the Evil One to tell him everything that he wanted to know.'

'And what did Salthenius ask?' I said at last.

Herr Rickert held a different note out to me. I took the paper from his trembling hand, and read the single sentence.

Anti-Christ will come from Paris . . .

'He told Salthenius that Bonaparte would come before the Corsican was even born!' he murmured darkly. 'He can tell you what you want to know, sir.'

Was this what it had come to? A devil-worshipper was going to tell me where to find Vulpius, having consulted his friendly house hold demon? I was prompted to take up my bag again, pay for what I owed, make my excuses, and leave him to it. What was to stop me? In retrospect, I realise that there was only one reason: I am a Prussian. The Dev il fascinates us all. Without exception.

'Daniel Salthenius speaks to me,' he continued. 'He placed that paper where I would find it. I was chosen . . . Chosen! Look here, sir,' he added sharply, pointing his finger like a magician's wand at the ma.s.s of papers on the table-top. 'This is our correspondence. From beyond the grave.'