I was looking up at the two life-size 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 inscribed 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 fool-proof. 'It was not stolen from the gallery at all.'
The hubbub around us had re-started. 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 I', 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 foot-fall. 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 third-rate 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 fights something should have materialized, some faint due 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, an 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 serionsness, 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 loose leaf 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 high-faced, goatee-bearded man in medieval 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' Piet 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 Crudfixions 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, well-authenticated masterworks, centre-pieces, 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 xsim, 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 Hermann Goering collection.'
'Interesting,' I commented. But few master-wors 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 in significance. 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.'