I stiffened. 'What makes you think that Kant would know?'

'Martin often goes to his house,' she replied without hesitation. 'He's been helping Kant to write a book.'

'He's been doing...what?' I spluttered.

'Not that he makes a penny out of it,' she went on resentfully. 'I've no idea what he does precisely. He comes home so tired out, he's not fit for work in the garden.'

'After your husband was dismissed from service,' I interposed, 'he was prohibited from ever visiting the house again. Professor Kant's friends keep a close watch to make sure there's no communication between them.'

Frau Lampe laughed shrilly. 'Even his dearest friends have to sleep, sir. Martin goes there after dark. I warned him, but he would not listen to me. The forest is a dangerous place at night.' She frowned and her voice was suddenly tense. 'You've no idea what my Martin's life was like in that house, have you? For thirty years he waited hand and foot on the most famous man in Prussia. If you knew the truth, sir, you wouldn't envy him.'

'Your husband has been most fortunate,' I said stiffly, 'in having served the n.o.blest mind that ever lived in Prussia.'

A veil seemed to fall over her face. 'I could tell you things that Kant's best friends don't know,' she replied in a low voice.

'Go on,' I said, steeling myself to hear the gossip that cast-off servants and their irate wives reserve for their former employers.

'Everyone in Konigsberg and elsewhere for all I know has heard of Professor Kant. His precise way of thinking, the regularity of his habits, the stern morality of his temperament, the impeccable elegance of his dress. Not a hair out of place, not a word out of turn, not a spot on his reputation. A living clock, they call him in this town. A clockwork man, says I. Nothing happens in his life by chance. No accidents befall him. Have you ever stopped to think how that affects the people in his service? Martin had no freedom, no life. Every single instant of every day, from the moment Martin woke him in the morning to the second when he tucked the Professor up in bed and blew out his candle, my husband was at his side, and never a single thought in his head but what his master put there. Waiting hand and foot on that man like a slave.'

She halted, her facial expression changed. Some rebellious thought seemed to pa.s.s through her mind and ripple the furrows on her brow like wind over still water.

'My husband was obsessed with the need to a.s.sist Professor Kant. When Herr Jachmann dismissed him, I realised that something was wrong. He blamed Martin...'

'It was not a question of blame,' I interrupted. 'Herr Jachmann decided that a younger man was needed.'

'Perhaps,' she replied, shrugging her shoulders. A nervous motion of her hands and the glinting brightness of her eyes suggested a fear of something that I could not name. 'Martin had a special task in that house. Something only he could do,' she added, her voice sinking to a barely audible whisper.

'A special task?' I echoed. Distressed by her husband's disappearance, I wondered whether she had begun to imagine plots.

' "I am the water in Kant's well," Martin told me once.'

'And what do you think he meant by that?'

Frau Lampe's eyes flashed up at me.

'Why, the book Professor Kant was writing!' she exclaimed. 'Martin told me he was helping his master to put the finishing touches to his final work. Kant's hand was not so steady as it used to be, his sight was poor, he needed a secretary to write it out for him.'

'Kant was dictating the text to your husband?' I burst out incredulously. 'Is that what you are suggesting, ma'am?'

Frau Lampe closed her eyes and nodded. 'Night after night after night. Often dawn was breaking before he got home. Martin isn't young any more, but he always was so diligent. He was so proud of what they were doing together. Helping Professor Kant rewrite his philosophy. That was what he said.'

'When did all of this begin?'

Frau Lampe grimaced with the effort of recall. A chasm split her brow. 'More than a year ago, sir. Martin was torn from my bed once more by that ogre. He came home when he could, but some nights he didn't come at all. And when he did come, he was not the same man. He'd sit by that window there, looking out like a haunted soul. He didn't say a word to me.'

I gazed at the murky window and tried to imagine what Martin Lampe had been thinking about. Had the murdering demon in his soul risen to the surface while his wife looked helplessly on?

'Did he tell you what this work involved?' I asked.

'He said I wouldn't understand. He and his master were exploring a new dimension. That's what he said, sir. A new dimension.'

Martin and Professor Kant, I noted. Not Professor Kant and Martin. Was that how she had interpreted Lampe's words, or had the husband presented the case to his wife in that light?

'Has your husband ever studied philosophy?' I asked.

'Oh no, sir. But he learnt a great deal from his master. Martin was always going on about the new philosophers who'd been attacking Kant. He said they'd be obliged to eat their words when the book came out.'

There it was again. The final testament of Immanuel Kant. The book that no one had ever seen. n.o.body, apart from Martin Lampe...

'That book turned Martin into a different man,' she continued. 'He frightened the life out of me sometimes, sir. He was obsessed, driven, and it was all Kant's doing.'

'Your husband was only executing his duty,' I suggested vaguely, 'unpleasant as it might have been.'

'Unpleasant?' she hissed. 'It was worse than that. Kant brought Martin to the verge of murder.'

'Indeed?' I said coldly, as if what she had just told me was a reasonable argument and not an obscene calumny.

'Martin told me so. One day a young gentleman came to visit Kant. When Martin served them tea, he said that they were pleasantly engaged in a discussion of philosophy...'

The relationship Jachmann had mentioned earlier flashed through my mind. 'Was the name of the visitor Gottlieb Fichte?'

Frau Lampe shook her head. 'I've no idea, sir. After they'd finished talking, Professor Kant accompanied his visitor to the door and saw him out.' She stared at me, a smile frozen on her face.

'What happened?' I asked.

'Kant told my husband to run after that young man and kill him with a knife.'

Here was the other side of Herr Jachmann's coin. Not a mad Martin Lampe, but a mad and murderous Immanuel Kant.

'Did your husband obey?'

'Of course, he did, sir. It was his duty. But that young philosopher ran away before Martin could catch up with him.'

'Would your husband have obeyed Kant up to that final point?'

She joined her hands as if she to pray. 'I begged him not to listen,' she whispered with a moan. 'Kant is senile, I said. He's demented. To tell you the truth, sir, I was glad when Herr Jachmann dismissed my husband. I thought he'd be out of harm's way. But nothing really changed. Professor Kant sent a secret message, calling him to the house under cover of night.'

'Frau Lampe,' I said, turning the argument aside, pointing to a piece of embroidered linen draped over the back of a chair. 'Are you interested in needlework?'

She glanced up in perplexity, then nodded.

'Where do you purchase your materials?'

She looked at me as if I were deranged.

'From a shop? A travelling draper, perhaps?' I suggested.

'There are two shops that I go to,' she said hesitantly.

'Do you know a man named Roland Lutbatz?'

'Yes, sir.'

'Have you bought anything from him recently?'

'I do not know him personally, sir,' she replied. 'He supplies goods to shopkeeper Reutlingen. I've seen him there on one or two occasions.' She stopped and frowned. 'What has Herr Lutbatz to do with my husband's disappearance?'

'He says that he spoke to your husband recently,' I answered. 'Martin was interested in buying needles for carding tapestry wool.'

'Carding wool?' she repeated, as if she did not understand.

'Did you instruct your husband to buy them for you?'

She did not reply. She was too frightened to answer, I could see that, calculating whether her husband would gain or lose by what she might have to say. I knew how I wished her to answer. I desired it with all the impelling force that Doctor Mesmer mentions when he speaks of the transference of thought. I wanted her to tell me that her husband had, indeed, bought those needles for her, and for no other purpose than that for which they were intended. I prayed with all my heart that the certainty I had felt in identifying the murderer would be dashed to smithereens. I wanted Lampe to be innocent. If Kant's unwitting influence had driven him to murder, there would be no end to the scandal.

'I did not ask my husband to purchase anything from Herr Lutbatz,' she said at last. 'He may have wished to surprise me with a gift. He sometimes does.' She studied my face carefully. 'Will this help you to understand what has happened to him, sir?'

'You have been a great help to me, Frau Lampe,' I said, standing up and preparing to leave, ever more convinced of the guilt of her husband. 'Please contact me if anything else occurs to you. With your a.s.sistance the police will find him soon, I'm certain.'

'There's something else, sir,' she said, stopping me on the doorstep. 'I should have mentioned it before, but I hoped it would not be necessary.'

'Of what are you speaking, Frau Lampe?'

'I'll show you, sir.'

She led the way quickly into the back garden, tramping through the deep, packed snow to the farthest corner of the enclosed land. It was a small plot in which Frau Lampe and her husband had managed to cultivate an apple tree and some rows of vegetables, the plants now frozen, black and withered with the frost. A dense, dark, untended wood stretched away up the hill behind the house. There was a vague, menacing quality about the place. Wisps of fog clung to the naked branches and the stark damp trunks. Dripping icicles hung from the trees like the stalact.i.tes in the gloomy caves of Bad Merrenheim.

'Can you see these marks?' she said, bending to the ground and indicating footprints in the frozen snow.

I knelt to examine them. They were little more than scuffs left by someone in a hurry wearing shoes unsuited to the weather and the terrain.

'It was snowing the night that Martin disappeared. I saw these tracks the morning after, when I went to the shed over there to get some dried herbs. It has not snowed since.'

'Why should he come this way?' I asked.

'It's a short cut to Professor...to the town,' she corrected herself.

Leaving her at the garden's edge, I ventured further into the wood, following the tracks until I reached a wild plum tree. Enshrined in the frozen snow was the first clearly delineated footprint. I stared at it for what seemed an eternity of time.

'Are you certain these traces were left by your husband?' I called back.

'I cut the soles of Martin's shoes myself. The leather was worn. I did not want him to fall and injure himself.'

I had seen the distinctive cross-cut that Frau Lampe had made three times before. In the drawing made by Officer Lublinsky at the scene of the first murder. The previous afternoon in Professor Kant's garden. And the night before, beside the lifeless body of Amadeus Koch in Sturtenstra.s.se.

Chapter 32.

After leaving Belefest, I returned to my office in a troubled mood.

I knew exactly what I ought to do. The killer had a name. Martin Lampe should be hunted down and prevented from striking again. Yet, there was something else that I had to do, something no magistrate should ever do. I determined to hide the ident.i.ty of the killer. Professor Kant must never learn who he was, or know how close he had been. If the murderer could be stopped, if I could cover his tracks, I would lead the investigation away from him until it fizzled out. If any man spoke the name of Martin Lampe again, it must only be to remember him as Professor Kant's valet. Anything else was a blasphemy.

I planted my elbows on the desk, pressed my head between my hands. I felt as though my brain might erupt from my throbbing skull. The first thing to do was to draw him into my net. He had murdered Sergeant Koch, but I had been the real target. Lampe had set his heart on slaughtering me, and he would not rest until he had eliminated the danger. Could I offer myself as a bait to entice him out of his hiding hole?

Suddenly, another course of action opened up before me, one which would set me for ever beyond the pale of the law.

Lampe had disappeared. His wife presumed that he was dead. She had come to the Fortress to report him missing. Could I turn the situation to my advantage? All I had to do was call Stadtschen, inform him that the man was nowhere to be found, provide a detailed description, and suggest that Lampe might have been murdered. A search would be set in motion. If he were found alive, he would be brought to me for questioning. Then, I would have him where I wanted him.

I poured myself a gla.s.s of wine, and drank it off in a single draught. As the liquid traced its acid path to my stomach, I realised with a shudder what would follow on once I had him in my custody. A terrible energy began to surge through my veins. My thoughts were swept up, invaded, conquered by the recollection of a cold grey morning ten years before. The intoxicating smell of blood as the blade scythed effortlessly through the neck of the French king. I clutched my fists to my eyes, trying to cancel that image from my memory.

I would kill Martin Lampe.

I sat still for quite some time, seeking to reclaim possession of myself, struggling to remember who I was, to understand what I had become what I was about to become. I could not risk a public trial. The manipulation of justice is no simple matter. If Lampe were forced to stand before me in the dock, I would have to prove his guilt in full. A magistrate is charged not only to condemn guilt, he must also demonstrate what led the felon to his error. Too much might be said in a courtroom debate of Professor Kant's influence over his valet. But if I gave orders to take the man up for his own safety, who would question my motives? If something happened while he was in my care, would any man dare to accuse me?

A short time later, a knock came at the door, and a soldier entered carrying despatches. 'Begging your pardon, sir,' he apologised, setting them down on my desk. 'Officer Stadtschen sent these.'

I glanced at the two letters, waiting for the door to close. The larger one, a white envelope with an imposing red seal, brought a lump to my throat as I slit it open. It was one of those missives all Prussians in the civil administration dread to receive, an anonymous secretary informing me that I was to give a full account of myself. A report of my investigation to date was required for submission to His Majesty, King Frederick Wilhelm, the following morning.

I let the paper fall on the table.

What was I to do? Could I avoid the Royal Imperative? Postpone the task until I was in a better position to reveal to the King what I wished him to know of the situation in Konigsberg? I picked the letter up, read it once more, let it drop back onto the table, turning my attention to the second despatch, which seemed less intimidating. This message bore no Hohenzollern seal. It was a single sheet of grey paper, folded in four, and closed with a loop of string. But as I read what Stadtschen had written, my heart began to race.

...a heap of bones. Tatters of clothing suggest the victim may have been a man. He had been chased through the woods, as streaks and stains of blood in the snow reveal, and was torn to pieces as he tried to escape. Pawprints indicate at least a dozen animals in the pack. The beasts were famished...

Another body had been found. Why had I not been informed at once?

My conception of the murders that Martin Lampe had committed was well-defined, precise in every detail. Whoever he was, the victim had not been killed by Lampe. But that did not diminish my impatience with Stadtschen's interfering ways. With Koch dead, he had spotted an opportunity for his own advancement. He had taken upon himself the responsibility to have the soldiers collect the bones in a sack, and bring them to the Fortress. 'The remains will be held for a day in case someone comes to claim the body,' he noted officiously. 'If no one does, burial in a pauper's grave will follow on.'

A groan of angered exasperation escaped me.

Did he think I would tell General Katowice what a clever fellow he was? Did he hope that I would mention him by name in my report to the King? I read on, my annoyance flaring into white-hot anger as I neared the end.

'Though not within the city walls, the place where the body was found still falls within the jurisdiction of Herr Procurator,' Stadtschen continued, 'being the abandoned hunting ground of the ancient feudal manor of...'

I jumped up from my chair, threw open the door, and called out the name of Stadtschen with all the force of rage in my lungs.

The empty corridor boomed with the sound. Footsteps clattered further off, and the echo of my cry was taken up by other voices, all of them calling the name of Stadtschen.

The man arrived at a gallop a minute later, his wig set lopsidedly on his head, the top b.u.t.ton of his uniform loose, as if my summons to duty had caught him unprepared. His sweaty face might have been wiped with a k.n.o.b of lard, and I took some pleasure in his discomfiture.

'Sir?' he said, breathing heavily after the exertion.