Then there was the matter of rotation. Now and again – as had to be the case, or suspicion might grow – one of the copies would have to grace the walls of the gallery proper. Those were worrying times, and I was careful to position the works in the least flattering, most shadowy locations, usually with a much more interesting picture nearby, to lure the spectator away. I would watch the browsers. Once or twice, an art student would come along and sketch the copied work. No one ever showed a moment’s doubt, and my confidence grew.

But then… then…

We had loaned works out before, of course – I’d told the dinner party as much. This or that cabinet minister might want something for the office, something to impress visitors. There would be discussions about a suitable work. It was the same with particular benefactors. They could be loaned a painting for weeks or even months. But I was always careful to steer prospective borrowers away from the twenty or so copies. It wasn’t as though there was any lack of choice: for each copy, there were fifty other paintings they could have. The odds, as Jance had assured me more than once, were distinctly in our favour.

Until the day the Prime Minister came to call.

This is a man who knows as much about art as I do about home brewing. There is almost a glee about his studious ignorance – and not merely of art. But he was walking around the Tate, for all the world like a dowager around a department store, and not seeing what he wanted.

‘Voore,’ he said at last. I thought I’d misheard him. ‘Ronny Voore. I thought you had a couple.’

My eyes took in his entourage, not one of whom would know a Ronny Voore if it blackballed them at the Garrick. But my superior was there, nodding slightly, so I nodded with him.

‘They’re not out at the moment,’ I told the PM.

‘You mean they’re in?’ He smiled, provoking a few fawning laughs.

‘In storage,’ I explained, trying out my own smile.

‘I’d like one for Number Ten.’

I tried to form some argument – they were being cleaned, restored, loaned to Philadelphia – but my superior was nodding again. And after all, what did the PM know about art? Besides, only one of our Voores was a fake.

‘Certainly, Prime Minister. I’ll arrange for it to be sent over.’

‘Which one?’

I licked my lips. ‘Did you have one in mind?’

He considered, lips puckered. ‘Maybe I should just have a little look…’

Normally, there were no visitors to the storerooms. But that morning, there were a dozen of us posed in front of Shrew Reclining and Herbert in Motion. Voore was very good with titles. I’ll swear, if you look at them long enough, you really can see – beyond the gobbets of oil, the pasted-on photographs and cinema stubs, the splash of emulsion and explosion of colour – the figures of a large murine creature and a man running.

The Prime Minister gazed at them in something short of thrall. ‘Is it “shrew” as in Shakespeare?’

‘No, sir, I think it’s the rodent.’

He thought about this. ‘Vibrant colours,’ he decided.

‘Extraordinary,’ my superior agreed.

‘One can’t help feeling the influence of pop art,’ one of the minions drawled. I managed not to choke: it was like saying one could see in Beryl Cook the influence of Picasso.

The PM turned to the senior minion. ‘I don’t know, Charles. What do you think?’

‘The shrew, I think.’

My heart leapt. The Prime Minister nodded, then pointed to Herbert in Motion. ‘That one, I think.’

Charles looked put out, while those around him tried to hide smiles. It was a calculated put-down, a piece of politics on the PM’s part. Politics had decided.

A fake Ronny Voore would grace the walls of Number 10 Downing Street.

I supervised the packing and transportation. It was a busy week for me: I was negotiating the loan of several Rothkos for an exhibition of early works. Faxes and insurance appraisals were flying. American institutions were very touchy about lending stuff. I’d had to promise a Braque to one museum – and for three months at that – in exchange for one of Rothko’s less inspired creations. Anyway, despite headaches, when the Voore went to its new home, I went with it.

I’d discussed the loan with Jance. He’d told me to switch the copy for some other painting, persisting that ‘no one would know’.

‘He’ll know,’ I’d said. ‘He wanted a Voore. He knew what he wanted.’

‘But why?’

Good question, and I’d yet to find the answer. I’d hoped for a first-floor landing or some nook or cranny out of the general view, but the staff seemed to know exactly where the painting was to hang – something else had been removed so that it could take pride of place in the dining-room. (Or one of the dining-rooms, I couldn’t be sure how many there were. I’d thought I’d be entering a house, but Number 10 was a warren, a veritable Tardis, with more passageways and offices than I could count.)

I was asked if I wanted a tour of the premises, so as to view the other works of art, but by that time my head really did ache, and I decided to walk back to the Tate, making it as far as Millbank before I had to rest beside the river, staring down at its sludgy flow. The question had yet to be answered: why did the PM want a Ronny Voore? Who in their right mind wanted a Ronny Voore these days?

The answer, of course, came with the telephone call.

Joe Hefferwhite was an important man. He had been a senator at one time. He was now regarded as a ‘senior statesman’, and the American President sent him on the occasional high-profile, high-publicity spot of troubleshooting and conscience-salving. At one point in his life, he’d been mooted for president himself, but of course his personal history had counted against him. In younger days, Hefferwhite had been a bohemian. He’d spent time in Paris, trying to be a poet. He’d walked a railway line with Jack Kerouac and Neal Cassady. Then he’d come into enough money to buy his way into politics, and had prospered there.

I knew a bit about him from some background reading I’d done in the recent past. Not that I’d been interested in Joseph Hefferwhite… but I’d been very interested in Ronny Voore.

The two men had met at Stanford initially, then later on had met again in Paris. They’d kept in touch thereafter, drifting apart only after ‘Heff ’ had decided on a political career. There had been arguments about the hippie culture, dropping out, Vietnam, radical chic – the usual sixties US issues. Then in 1974 Ronny Voore had laid down on a fresh white canvas, stuck a gun in his mouth, and gifted the world his final work. His reputation, which had vacillated in life, had been given a boost by the manner of his suicide. I wondered if I could make the same dramatic exit. But no, I was not the dramatic type. I foresaw sleeping pills and a bottle of decent brandy.

After the party.

I was wearing my green Armani, hoping it would disguise the condemned look in my eyes. Joe Hefferwhite had known Voore, had seen his style and working practice at first hand. That was why the PM had wanted a Voore: to impress the American. Or perhaps to honour his presence in some way. A political move, as far from aesthetics as one could wander. The situation was not without irony: a man with no artistic sensibility, a man who couldn’t tell his Warhol from his Whistler… this man was to be my downfall.

I hadn’t dared tell Jance. Let him find out for himself afterwards, once I’d made my exit. I’d left a letter. It was sealed, marked Personal, and addressed to my superior. I didn’t owe Gregory Jance anything, but hadn’t mentioned him in the letter. I hadn’t even listed the copied works – let them set other experts on them. It would be interesting to see if any other fakes had found their way into the permanent collection.

Only of course I wouldn’t be around for that.