'Perhaps I should let the shell speak for itself,' I demurred. My wife was less tolerant of my tendency to bore. I lifted the shell to my ear and listened to the whispering trumpet.

The helix reflected the swishing of the waves, the contours of the shell in some way magnifying the sounds, so that they echoed with the darker murmur of deep water. Around me the breakers fell among the rocks with a rhythmic roar and sigh, but from the shell poured an extraordinary confusion of sounds, and I seemed to be listening not merely to the waves breaking on the shore below me but to an immense ocean lapping all the beaches of the world. I could hear the roar and whistle of giant rollers, shingle singing in the undertow, storms and typhonic winds boiling the sea into a maelstrom. Then abruptly the scene seemed to shift, and I heard the calm measures of a different sea, a steaming shallow lagoon through whose surface vast ferns protruded, where halfsubmerged leviathans lay like sandbanks under a benign sun My companion was watching me, her high face lifted to catch the leaping spray. 'Did you hear the sea?'

I pressed the shell to my ear. Again I heard the sounds of ancient water, this time of an immense storm in progress, a titanic struggle against the collapsing isthmuses of a sinking continent. I could hear the growling of gigantic saurians, the cries of reptile birds diving from high cliffs on to their prey below, their ungainly wings unshackling as they fell.

Astonished, I squeezed the shell in my hands, feeling the hard calcareous spines as if they might spring open the shell's secret.

The woman still watched me. By some freak of the fading light she appeared to have grown in height, her shoulders almost overtopping my head.

'I... can't hear anything,' I said uncertainly.

'Listen to it!' she admonished me. 'That shell has heard the seas of all time, every wave has left its echo there.'

The first foam splashed across my feet, staining the dried straps of my sandals. A narrowing causeway of rocks still led back to the beach. The cave had vanished, its mouth spewing bubbles as the waves briefly receded.

I pointed to the cliff. 'Is there a path? A way down to the sea?'

'To the sea? Of course!' The wind lifted the train of her robe, and I saw her bare feet, seaweed wreathed around her toes. 'Now listen to the shell. The sea is waking for you.'

I raised the shell with both hands. This time I closed my eyes, and as the sounds of the ancient wind and water echoed in my ears I saw a sudden image of the lonely bay millions of years earlier. High cliffs of white shale reached to the sky, and huge reptiles sidled along the coarse beaches, baying at the grotesque armoured fish which lunged at them from the shallows. Volcanic cones ringed the horizon, their red vents staining the sky.

'What can you hear?' my companion asked me insistently, evidently disappointed. 'The sea and the wind?'

'I hear nothing,' I said thickly. 'Only a whispering.'

The noise erupted from the shell's mouth, the harsh bellows of the saurians competing with the sea. Suddenly I heard another sound above this babel, a thin cry that seemed to come from the cave in which I had sheltered. Searching the image in my mind, I could see the cave mouth set into the cliff above the heads of the jostling reptiles.

'Wait!' I waved the woman away, ignoring the waves that sluiced across my feet. As the sea receded, I pressed my ear to the conch, and heard again the faint human cry, a stricken plea for rescue 'Can you hear the sea now?' The woman reached to take the shell from me.

I held to it tightly and shouted above the waves. 'Not this sea! My God, I heard a man crying!'

For a moment she hesitated, uncertain what to make of this unexpected remark. 'A man? Who, tell me! Give it to me! It was only a drowned sailor!'

Again I snatched the shell away from her. Listening, I could still hear the voice calling, now and then lost in the roar of the reptiles. A sailor, yes, but a mariner from the distant future, marooned millions of years ago in this cave on the edge of a Triassic sea, guarded by this strange naiad of the deep who even now guided me to the waves.

She had moved to the edge of the rock, the strands of her hair shimmering across her face in the wind. With a hand she beckoned me towards her.

For the last time I lifted the shell to my ear, and for the last time heard that faint plaintive cry, lost on the reeling air.

'Hheelp!'

Closing my eyes, I let the image of the ancient shore fill my mind, for a fleeting instant saw a small white face watching from the cave mouth. Whoever he was, had he despaired of returning to his own age, selected a beautiful shell and cast it into the sea below, hoping that one day someone would hear his voice and return to save him?

'Come! It's time to leave!' Although she was a dozen feet from me, her outstretched hands seemed almost to touch mine. The water raced around her robe, swirling it into strange liquid patterns. Her face watched me like that of some monstrous fish.

'No!'

With sudden fury I stepped away from her, then turned and hurled the great shell far out into the deep water beyond her reach. As it vanished into the steep waves I heard a flurry of heavy robes, almost like the beating of leathery wings.

The woman had gone. Quickly I leapt on to the nearest rock of the causeway, slipped into the shallows between two waves and then clambered to safety. Only when I had reached the shelter of the cliffs did I look back.

On the ledge where she had stood a large lizard watched me with empty eyes.

1964.

The Lost Leonardo The disappearance or, to put it less euphemistically the theft of the Crucifixion by Leonardo da Vinci from the Museum of the Louvre in Paris, discovered on the morning of April 19, 1965, caused a scandal of unprecedented proportions. A decade of major art thefts, such as those of Goya's Duke of Wellington from the National Gallery, London, and collections of impressionists from the homes of millionaires in the South of France and California, as well as the obviously inflated prices paid in the auction rooms of Bond Street and the Rue de Rivoli, might have been expected to accustom the general public to the loss of yet another overpublicized masterpiece, but in fact the news of its disappearance was received by the world with genuine consternation and outrage. From all over the globe thousands of telegrams poured in daily at the Quai d'Orsay and the Louvre, the French consulates at Bogota and Guatemala City were stoned, and the panache and finesse of press attaches at every embassy from Buenos Aires to Bangkok were strained to their not inconsiderable limits.

I myself reached Paris over twentyfour hours after what was being called 'the great Leonardo scandal' had taken place, and the atmosphere of bewilderment and indignation was palpable. All the way from Orly Airport the newspaper headlines on the kiosks blazoned the same story.

As the Continental Daily Mail put it succinctly: LEONARDO'S CRUCIFIXION STOLEN 5 Million Masterpiece Vanishes from Louvre Official Paris, by all accounts, was in uproar. The hapless director of the Louvre had been recalled from a Unesco conference in Brasilia and was now on the carpet at the Elysee Palace, reporting personally to the President, the Deuxieme Bureau had been alerted, and at least three ministers without portfolio had been appointed, their political futures staked to the recovery of the painting. As the President himself had remarked at his press conference the previous afternoon, the theft of a Leonardo was an affair not only for France, but for the entire world, and in a passionate plea he enjoined everyone to help effect its speedy return (despite the emotionally charged atmosphere, cynical observers noticed that this was the first crisis of his career when the Great Man did not conclude his peroration with 'Vive La France').

My own feelings, despite my professional involvement with the fine arts I was, and am, a director of Northeby's, the worldfamous Bond Street auctioneers by and large coincided with those of the general public. As the taxi passed the Tuileries Gardens I looked out at the crude halftone illustrations of da Vinci's effulgent masterpiece reproduced in the newspapers, recalling the immense splendour of the painting, with its unparalleled composition and handling of chiaroscuro, its unsurpassed technique, which together had launched the High Renaissance and provided a beacon for the sculptors, painters and architects of the Baroque.

Despite the two million reproductions of the painting sold each year, not to mention the countless pastiches and inferior imitations, the subject matter of the painting still retained its majestic power. Completed two years after da Vinci's Virgin and St Anne, also in the Louvre, it was not only one of the few Leonardos to have survived intact the thousand eager hands of the retouchers of four centuries, but was the only painting by the master, apart from the dissolving and barely visible Last Supper, in which he handled a composition with a large landscape and a huge gallery of supporting figures.

It was this latter factor, perhaps, which gave the painting its terrifying, hallucinatory power. The enigmatic, almost ambivalent expression on the face of the dying Christ, the hooded serpentine eyes of the Madonna and Magdalene, these characteristic signatures of Leonardo became more than mere mannerisms when set against the huge spiral concourse of attendant figures that seemed to swirl up into the distant sky across the Place of Bones, transforming the whole image of the crucifixion into an apocalyptic vision of the resurrection and judgment of mankind. From this single canvas had come the great frescoes of Michelangelo and Raphael in the Sistine Chapel, the entire schools of Tintoretto and Veronese. That someone should have the audacity to steal it was a tragic comment on mankind's respect for its greatest monuments.

And yet, I wondered as we arrived at the offices of Galleries Normande et Cie in the Madeleine, had the painting really been stolen at all? Its size, some 15 feet by 18 feet, and weight it had been transferred from the original canvas to an oak panel precluded a single fanatic or psychopath, and no gang of professional art thieves would waste their time stealing a painting for which there would be no market. Could it be, perhaps, that the French government was hoping to distract attention from some other impending event, though nothing less than the reintroduction of the monarchy and the coronation of the Bourbon Pretender in Notre Dame would have required such an elaborate smokescreen.

At the first opportunity I raised my doubts with Georg de Stael, the director of Galleries Normande with whom I was staying during my visit. Ostensibly I had come to Paris to attend a conference that afternoon of art dealers and gallery directors who had also suffered from thefts of major works of art, but to any outsider our mood of elation and high spirits would have suggested some other motive. This, of course, would have been correct. Whenever a large stone is cast into the turbid waters of international art, people such as myself and Georg de Stael immediately take up our positions on the bank, watching for any unusual ripple or malodorous bubble. Without doubt the theft of the Leonardo would reveal a good deal more than the identity of some crackpot cat burglar. All the darker fish would now be swimming frantically for cover, and a salutary blow had been struck at the official establishment of senior museum curators and directors.

Such feelings of revenge obviously animated Georg as he moved with dapper, lightfooted ease around his desk to greet me. His blue silk summer suit, well in advance of the season, glittered like his smooth brilliantined hair, his svelte rapacious features breaking into a smile of roguish charm.

'My dear Charles, I assure you, categorically, the confounded picture has actually gone , Georg shot out three inches of elegant chalkblue cuff and snapped his hands together ' puff! For once everyone is speaking the truth. What is even more remarkable, the painting was genuine.'

'I don't know whether I'm glad to hear that or not,' I admitted. 'But it's certainly more than you can say for most of the Louvre and the National Gallery.'

'Agreed.' Georg straddled his desk, his patent leather shoes twinkling in the light. 'I had hoped that this catastrophe might induce the authorities to make a clean breast of some of their socalled treasures, in an attempt, as it were to dispel some of the magic surrounding the Leonardo. But they are in a complete fuddle.'

For a moment we both contemplated what such a sequence of admissions would do to the art markets of the world the prices of anything even remotely genuine would soar as well as to the popular image of Renaissance painting as something sacrosanct and unparalleled. However, this was not to gainsay the genius of the stolen Leonardo.

'Tell me, Georg,' I asked. 'Who stole it?' I assumed he knew.

For the first time in many years Georg seemed at a loss for an answer. He shrugged helplessly. 'My dear Charles, I just do not know. It's a complete mystery. Everyone is as baffled as you are.'

'In that case it must be an inside job.'

'Definitely not. The present crowd at the Louvre are beyond reproach.' He tapped the telephone. 'This morning I was speaking to some of our more dubious contacts Antweiler in Messina and Kolenskya in Beirut and they are both mystified. In fact they're convinced that either the whole thing is a putup affair by the present regime, or else the Kremlin itself is involved.'

'The Kremlin?' I echoed incredulously. At the invocation of this name the atmosphere heightened, and for the next half an hour we spoke in whispers.

The conference that afternoon, at the Palais de Chaillot, offered no further clues. Chief DetectiveInspector Carnot, a massive gloomy man in a faded blue suit, took the chair, flanked by other agents of the Deuxieme Bureau. All of them looked tired and dispirited; by now they were having to check up on some dozen false alarms each hour. Behind them, like a hostile jury, sat a soberfaced group of investigators from Lloyds of London and Morgan Guaranty Trust of New York. By contrast, the two hundred dealers and agents sitting on the gilt chairs below the platform presented an animated scene, chattering away in a dozen languages and flying a score of speculative kites.

After a brief resum, delivered in a voice of sepulchral resignation, Inspector Carnot introduced a burly Dutchman next to him, Superintendent Jurgens of the Interpol bureau at The Hague, and then called on M. Auguste Pecard, assistant director of the Louvre, for a detailed description of the theft. This merely confirmed that the security arrangements at the Louvre were firstclass and that it was absolutely impossible for the painting to have been stolen. I could see that Pecard was still not entirely convinced that it had gone.

'... the pressure panels in the floor surrounding the painting have not been disturbed, nor have the two infrared beams across its face been broken. Gentlemen, I assure you it is impossible to remove the painting without first dismantling the bronze frame. This alone weighs eight hundred pounds and is bolted into the wall behind it. But the electric alarm circuit which flows through the bolts was not interrupted..

I was looking up at the two lifesize photographs of the front and reverse faces of the painting fastened to the screens behind the dais. The latter showed the back of the oak panel with its six aluminium ribs, contact points for the circuit and a mass of chalked graffiti enscribed over the years by the museum laboratories. The photographs had been taken the last time the picture was removed for cleaning, and after a brief bout of questioning it transpired that this had been completed only two days before the theft.

At this news the atmosphere of the conference changed. The hundred private conversations ceased, coloured silk handkerchiefs were returned to their breast pockets.

I nudged Georg de Stael. 'So that explains it.' Obviously the painting had disappeared during its period in the laboratory, where the security arrangements would be less than foolproof. 'It was not stolen from the gallery at all.'

The hubbub around us had restarted. Two hundred noses once again were lifted to scent the trail. So the painting had been stolen, and was somewhere at large in the world. The rewards to the discoverer, if not the Legion of Honour or a Knighthood, then at least complete freedom from all income tax and foreign exchange investigations, hovered like a spectre before us.

On the way back, however, Georg stared sombrely through the window of the taxi.

'The painting was stolen from the gallery,' he said to me pensively. 'I saw it there myself just twelve hours before it vanished.' He took my arm and held it tightly. 'We'll find it, Charles, for the glory of Northeby's and the Galleries Normande. But, my God, the man who stole it was a thief out of this world!'

So began the quest for the missing Leonardo. I returned to London the next morning, but Georg and I were in regular contact by telephone. Initially, like all the others on its trail, we merely listened, ears to the ground for an unfamiliar footfall. In the crowded auction rooms and galleries we waited for the indiscreet word, for the giveaway clue. Business, of course, was buoyant; every museum and private owner with a thirdrate Rubens or Raphael had now moved up a rung. With luck the renewed market activity would uncover some distant accomplice of the thief, or a previous substitute for the Leonardo perhaps a pastiche Mona Lisa by one of Verrocchio's pupils would be jettisoned by the thief and appear on one of the shadier markets. If the hunt for the vanished painting was conducted as loudly as ever in the outside world, within the trade all was quiet and watchful.

In fact, too quiet. By rights something should have materialized, some faint clue should have appeared on the fine filters of the galleries and auction rooms. But nothing was heard. As the wave of activity launched by the displaced Leonardo rolled past and business resumed its former tempo, inevitably the painting became just another on the list of lost masterpieces.

Only Georg de Stael seemed able to maintain his interest in the search. Now and then he would put through a call to London, requesting some obscure piece of information about an anonymous buyer of a Titian or Rembrandt in the late 18th century, or the history of some damaged copy by a pupil of Rubens or Raphael. He seemed particularly interested in works known to have been damaged and subsequently restored, information with which many private owners are naturally jealous of parting.

Consequently, when he called to see me in London some four months after the disappearance of the Leonardo, it was not in a purely jocular sense that I asked: 'Well, Georg, do you know who stole it yet?'

Unclipping a large briefcase, Georg smiled at me darkly. 'Would it surprise you if I said "yes"? As a matter of fact, I don't know, but I have an idea, a hypothesis, shall we say. I thought you might be interested to hear it.'

'Of course, Georg,' I said, adding reprovingly: 'So this is what you've been up to.'

He raised a thin forefinger to silence me. Below the veneer of easy charm I noticed a new mood of seriousness, a cutting of conversational corners.

'First, Charles, before you laugh me out of your office, let's say that I consider my theory completely fantastic and implausible, and yet , he shrugged deprecatingly ' it seems to be the only one possible. To prove it I need your help.'

'Given before asked. But what is this theory? I can't wait to hear.'

He hesitated, apparently uncertain whether to expose his idea, and then began to empty the briefcase, taking out a series of looseleaf files which he placed in a row facing him along the desk. These contained what appeared to be photographic reproductions of a number of paintings, areas within them marked with white ink. Several of the photographs were enlargements of details, all of a highfaced, goateebearded man in mediaeval costume.

Georg inverted six of the larger plates so that I could see them. 'You recognize these, of course?'

I nodded. With the exception of one, Rubens' Pieta in the Hermitage Museum at Leningrad, I had seen the originals of them all within the previous five years. The others were the missing Leonardo Crucifixion, the Crucifixions by Veronese, Goya and Holbein, and that by Poussin, entitled The Place of Golgotha. All were in public museums the Louvre, San Stefano in Venice, the Prado and the Ryksmuseum, Amsterdam and all were familiar, wellauthenticated masterworks, centrepieces, apart from the Poussin, of major national collections. 'It's reassuring to see them. I trust they're all in good hands. Or are they next on the mysterious thief's shopping list?'

Georg shook his head. 'No, I don't think he's very interested in these. Though he keeps a watching brief over them.' Again I noticed the marked change in Georg's manner, the reflective private humour. 'Do you notice anything else?'

I compared the photographs again. 'They're all crucifixions. Authentic, except perhaps in minor details. They were all easel paintings.' I shrugged.

'They all, at some time, have been stolen.' Georg moved quickly from right to left. 'The Poussin from the Chateau Loire collection in 1822, the Goya in 1806 from the Monte Cassino monastery, by Napoleon, the Veronese from the Prado in 1891, the Leonardo four months ago as we know, and the Holbein in 1943, looted for the Herman Goering collection.'

'Interesting,' I commented. 'But few masterworks haven't been stolen at some time. I hope this isn't a key point in your theory.'

'No, but in conjunction with another factor it gains insignificance. Now.' He handed the Leonardo reproduction to me. 'Anything unusual there?' When I shook my head at the familiar image he picked up another photograph of the missing painting. 'What about that one?'

The photographs had been taken from slightly different perspectives, but otherwise seemed identical. 'They are both of the original Crucifixion,' Georg explained, 'taken in the Louvre within a month of its disappearance.'

'I give up,' I admitted. 'They seem the same. No wait a minute!' I pulled the table light nearer and bent over the plates, as Georg nodded. 'They're slightly different. What is going on?'

Quickly, figure by figure, I compared the photographs, within a few moments seized on the minute disparity. In almost every particular the pictures were identical, but one figure out of the score or more on the crowded field had been altered. On the left, where the procession wound its way up the hillside towards the three crosses, the face of one of the bystanders had been completely repainted. Although, in the centre of the painting, the Christ hung from the cross some hours after the crucifixion, by a sort of spatiotemporal perspective a common device in all Renaissance painting for overcoming the static nature of the single canvas the receding procession carried the action backwards through time, so that one followed the invisible presence of the Christ on his painful last ascent of Golgotha.

The figure whose face had been repainted formed part of the crowd on the lower slopes. A tall powerfully built man in a black robe, he had obviously been the subject of special care by Leonardo, who had invested him with the magnificent physique and serpentine grace usually reserved for his depiction of angels. Looking at the photograph in my left hand, the original unretouched version, I realized that Leonardo had indeed intended the figure to represent an angel of death, or rather, one of those agents of the unconscious, terrifying in their enigmatic calm, in their brooding ambivalence, who seem to preside in his paintings over all man's deepest fears and longings, like the greyfaced statues that stare down from the midnight cornices of the necropolis at Pompeii.

All this, so typical of Leonardo and his curious vision, seemed to be summed up by the face of this tall angelic figure. Turned almost in profile over the left shoulder, the face looked up towards the cross, a faint flicker of pity investing the grey saturnine features. A high forehead, slightly flared at the temples, rose above the handsome semitic nose and mouth. A trace of a smile, of compassionate resignation and understanding, hung about the lips, providing a solitary source of light which illuminated the remainder of the face partly obscured by the shadows of the thundering sky.

In the photograph on my right, however, all this had been altered completely. The whole character of this angelic figure had been replaced by a new conception. The superficial likeness remained, but the face had lost its expression of tragic compassion. The later artist had reversed its posture altogether, and the head was turned away from the cross and over the right shoulder towards the earthly city of Jerusalem whose spectral towers rose like a city of Miltonic hell in the blue dusk. While the other bystanders followed the ascending Christ as if helpless to assist him, the expression on the face of the blackrobed figure was arrogant and critical, the tension of the averted neck muscles indicating that he had swung his head away almost in disgust from the spectacle before him.

'What is this?' I asked, pointing to the latter photograph. 'Some lost pupil's copy? I can't see why '

Georg leaned forward and tapped the print. 'That is the original Leonardo. Don't you understand, Charles? The version on your left which you were admiring for so many minutes was superimposed by some unknown retoucher, only a few years after da Vinci's death.' He smiled at my scepticism. 'Believe me, it's true. The figure concerned is only a minor part of the composition, no one had seriously examined it before, as the rest of the painting is without doubt original. These additions were discovered five months ago shortly after the painting was removed for cleaning. The infrared examination revealed the completely intact profile below.'

He passed two more photographs to me, both largescale details of the head, in which the contrasts of characterization were even more obvious. 'As you can see from the brushwork in the shading, the retouching was done by a righthanded artist, whereas we know, of course, that da Vinci was lefthanded.'

'Well...' I shrugged. 'It seems strange. But if what you say is correct, why on earth was such a small detail altered? The whole conception of the character is different.'

'An interesting question,' Georg said ambiguously. 'Incidentally, the figure is that of Ahasuerus, the Wandering Jew.' He pointed to the man's feet. 'He's always conventionally represented by the crossed sandalstraps of the Essene Sect, to which Jesus himself may have belonged.'

I picked up the photographs again. 'The Wandering Jew,' I repeated softly. 'How curious. The man who taunted Christ to move faster and was condemned to rove the surface of the earth until the Second Coming. It's almost as if the retoucher were an apologist for him, superimposing this expression of tragic pity over Leonardo's representation. There's an idea for you, Georg. You know how courtiers and wealthy merchants who gathered at painters' studios were informally incorporated into their paintings perhaps Ahasuerus would move around, posing as himself, driven by a sort of guilt compulsion, then later steal the paintings and revise them. Now there is a theory.'

I looked across at Georg, waiting for him to reply. He was nodding slowly, eyes watching mine in unspoken agreement, all trace of humour absent. 'Georg!' I exclaimed. 'Are you serious? Do you mean '

He interrupted me gently but forcefully. 'Charles, just give me a few more minutes to explain. I warned you that my theory was fantastic.' Before I could protest he passed me another photograph. 'The Veronese Crucifixion. See anyone you recognize? On the bottom left.'

I raised the photograph to the light. 'You're right. The late Venetian treatment is different, far more pagan, but it's quite obvious. You know, Georg, it's a remarkable likeness.'

'Agreed. But it's not only the likeness. Look at the pose and characterization.'

Identified again by his black robes and crossed sandalstraps, the figure of Ahasuerus stood among the throng on the crowded canvas. The unusual feature was not so much that the pose was again that of the retouched Leonardo, with Ahasuerus now looking with an expression of deep compassion at the dying Christ an altogether meaningless interpretation but the remarkable likeness between the two faces, almost as if they had been painted from the same model. The beard was perhaps a little fuller, in the Venetian manner, but the planes of the face, the flaring of the temples, the handsome coarseness of the mouth and jaw, the wise resignation in the eyes, that of some welltravelled physician witnessing an act of barbaric beauty and power, all these were exactly echoed from the Leonardo.

I gestured helplessly. 'It's an amazing coincidence.'

Georg nodded. 'Another is that this painting, like the Leonardo, was stolen shortly after being extensively cleaned. When it was recovered in Florence two years later it was slightly damaged, and no further attempts were made to restore the painting.' Georg paused. 'Do you see my point, Charles?'

'More or less. I take it you suspect that if the Veronese were now cleaned a rather different version of Ahasuerus would be found. Veronese's original depiction.'

'Exactly. After all, the present treatment makes no sense. If you're still sceptical, look at these others.'

Standing up, we began to go through the remainder of the photographs. In each of the others, the Poussin, Holbein, Goya and Rubens, the same figure was to be found, the same dark saturnine face regarding the cross with an expression of compassionate understanding. In view of the very different styles of the artists, the degree of similarity was remarkable. In each, as well, the pose was meaningless, the characterization completely at odds with the legendary role of Ahasuerus.

By now the intensity of Georg's conviction was communicating itself to me physically. He drummed the desk with the palm of one hand. 'In each case, Charles, all six paintings were stolen shortly after they had been cleaned even the Holbein was looted from the Herman Goering collection by some renegade SS after being repaired by concentration camp inmates. As you yourself said, it's almost as if the thief was unwilling for the world to see the true image of Ahasuerus's character exposed and deliberately painted in these apologies.'

'But Georg, you're making a large assumption there. Can you prove that in each case, apart from the Leonardo, there is an original version below the present one?'

'Not yet. Naturally galleries are reluctant to give anyone the opportunity to show that their works are not entirely genuine. I know all this is still hypothesis, but what other explanation can you find?'

Shaking my head, I went over to the window, letting the noise and movement of Bond Street cut through Georg's heady speculations. 'Are you seriously suggesting, Georg, that the blackrobed figure of Ahasuerus is promenading somewhere on those pavements below us now, and that all through the centuries he's been stealing and retouching paintings that represent him spurning Jesus? The idea's ludicrous!'

'No more ludicrous than the theft of the painting. Everyone agrees it could not have been stolen by anyone bounded by the laws of the physical universe.'