'Many thanks, chaps,' he said. 'You can all go home now. I'll deal with the paperwork in the morning.'

As Mr Dickens was the last to leave the building that night, he locked up before walking off in the direction of Green Park station. He didn't notice a man standing in the entrance of an antique shop on the opposite side of the street.

Once Mr Dickens was out of sight, the man emerged from the shadows and walked to the nearest telephone box on Curzon Street. He had four pennies ready, but then he never left anything to chance. He dialled a number he knew by heart. When he heard a voice on the other end of the line, he pressed button A, and said, 'An empty thinker is spending the night in Bond Street, sir.'

'Thank you, colonel,' said Sir Alan, 'and there's another matter I need you to handle. I'll be in touch.' The line went dead.

After BOAC flight number 714 from Buenos Aires touched down at London Airport the following morning, Don Pedro wasn't at all surprised that every one of his and Diego's suitcases was opened, checked and double checked by several over-zealous customs officials. When they had finally placed a chalk cross on the side of the last case, Martinez sensed a little frisson of disappointment among the customs officers, as he and his son walked out of the airport.

Once they were seated in the back of the Rolls-Royce and on their way to Eaton Square, Don Pedro turned to Diego and said, 'All you have to remember about the British is that they lack imagination.'

42

ALTHOUGH THE FIRST lot would not come under the hammer until seven that evening, the auction house was packed long before the appointed hour, as it always was on the opening night of a major Impressionist sale.

The three hundred seats were filled with gentlemen wearing dinner jackets, while many of the ladies were adorned in long gowns. They might have been attending an opening night at the opera, and indeed this promised to be as dramatic as anything on offer at Covent Garden. And although there was a script, it was always the audience who had the best lines.

The invited guests fell into several different categories. The serious bidders, who often turned up late because they had reserved seats, and might not be interested in the first few lots, which, like minor characters in a Shakespeare play, are simply there to warm up the audience. The dealers and the gallery owners, who preferred to stand at the back with their colleagues and share among themselves any scraps that fell from the rich man's table, when a lot failed to reach its reserve price and had to be withdrawn. And then there were those who treated it as a social occasion. They had no interest in bidding, but enjoyed the spectacle of the super-rich taking up arms against each other.

And last, the more deadly of the species, with sub-categories of their own. The wives, who came to watch how much their husbands would spend on objects that they had no interest in, preferring to spend their money in other establishments in the same street. Then there were the girlfriends, who remained silent, because they were hoping to become wives. And finally, the simply beautiful, who had no other purpose in life than to remove the wives and girlfriends from the battlefield.

But, as with everything in life, there were exceptions to the rule. One such was Sir Alan Redmayne, who would be there to represent his country. He would be bidding for lot 29, but hadn't yet decided how high he would go.

Sir Alan was not unfamiliar with the West End auction houses and their strange traditions. Over the years he had built up a small collection of eighteenth-century English water-colours, and he had also, on occasion, bid on behalf of the government, for a painting or sculpture his masters felt should not be allowed to leave the country. However, this was the first time in his career that he would be bidding for a major work in the hope of being outbid by someone from overseas.

The Times had predicted that morning that Rodin's The Thinker could sell for £100,000  -  a record for any piece by the French master. However, what The Times couldn't know was that Sir Alan intended to take the bidding above £100,000, because not until then could he be certain that the only bidder left on the floor would be Don Pedro Martinez, who believed the statue's true value to be over eight million pounds.

Giles had asked the cabinet secretary the one question he'd been trying to avoid answering: 'If you were to end up outbidding Martinez, what would you do with the sculpture?'

'It will be given a home in the National Gallery of Scotland,' he had replied, 'as part of the government's arts acquisition policy. You will be able to write about it in your memoirs, but not until after I'm dead.'

'And if you should prove to be right?'

'Then it will warrant a whole chapter in my memoirs.'

When Sir Alan entered the auction house, he slipped into a seat in the back left-hand corner of the sale room. He had phoned Mr Wilson earlier to let him know he would be bidding on lot 29, and sitting in his usual place.

By the time Mr Wilson climbed the five steps to the rostrum, most of the major players had taken their seats. Standing on both sides of the auctioneer was a row of Sotheby's employees. Most of them would be bidding for clients who were unable to attend in person, or who couldn't trust themselves not to be carried away by the occasion and end up bidding far more than they had intended. On the left-hand side of the room stood a long table on a raised platform. Seated behind it were some of the auction house's most experienced senior staff. On the table in front of them was a row of white telephones that would only be whispered into when the lot their client was interested in came up for sale.

From his seat at the back of the room, Sir Alan could see that almost every place was taken. However, there were still three empty chairs in the third row that must have been reserved for a major client. He wondered who would be seated on either side of Don Pedro Martinez. He flicked through the pages of his catalogue until he came to Rodin's The Thinker, lot 29. There would be more than enough time for Martinez to make an entrance.

At 7 p.m. precisely, Mr Wilson gazed down at his clients and, like the Pope, smiled benignly. He tapped the microphone and said, 'Good evening, ladies and gentlemen, and welcome to Sotheby's Impressionist sale. Lot number one,' he announced, glancing to his left to make sure the porter had placed the correct picture on the easel, 'is a delightful Degas pastel, showing two ballerinas in rehearsal at the Trocadero. I'll open the bidding at five thousand pounds. Six thousand. Seven thousand. Eight thousand . . .'

Sir Alan watched with interest as almost all of the early lots exceeded their estimates, proving, as The Times had suggested that morning, that there was a new breed of collectors who had made their fortunes since the war, and wished to show they had arrived by investing in art.

It was during the twelfth lot that Don Pedro Martinez entered the room, accompanied by two young men. Sir Alan recognized Martinez's youngest son, Bruno, and assumed the other must be Sebastian Clifton. The presence of Sebastian convinced him that Martinez must be confident that the money was still inside the statue.

The dealers and gallery owners began to discuss among themselves if Martinez was likely to be more interested in lot 28, A Corner of the Garden at St Paul's Hospital at St Remy by Van Gogh, or lot 29, Rodin's The Thinker.

Sir Alan had always considered himself to be a calm and collected man under pressure, but at that moment he felt his heart rate rising beat by beat as each new lot was placed on the easel. When the bidding opened at £80,000 for A Corner of the Garden at St Paul's Hospital at St Remy, and the hammer finally came down at £140,000, a record for a Van Gogh, he took out his handkerchief and dabbed his forehead.