It did not seem strange to me at the time that Francis had all this information at his nimble fingertips. The truth was that he must have arrived at the idea weeks, even months before, and spent time researching its viability in preparation for this day. During the whole speech he gesticulated wildly, but kept the dripping bundle of ice in the tea towel pressed firmly against his swelling eye, so that he seemed like a pirate revealing the location of buried treasure from his deathbed. He had an answer for each of my objections, and so the usual tide of his enthusiasm, quite strong enough on its own to pull me out of the shallow waters of my own intentions and into the blue deeps, was aided by reasoned argument.

‘But . . . but they have chemical analysis, to date these pictures, they know the pigments and the composition of the materials . . .’ I protested.

‘Yes, yes they do,’ he replied, nodding as if he had been waiting for me to raise just that point, ‘but consider this: firstly, with a watertight provenance, no one would ever bother to check. Chemical analysis is a last recourse to settle questions of doubtful authenticity. Secondly, if we sell the picture illegally, we buy ourselves a certain amount of security. The buyer resigns themselves to never being able to sell the picture on the legitimate market, where any such fraud might be detected, and will never be able to raise the alarm. The picture will never be gone, and there will never be two in circulation. Why would they check?’

The truth of it began to dawn on me, warming the skin of my face. My hands started to tingle. I opened my mouth to speak, and closed it again. I was paralysed by the ridiculousness of his proposition. The impossibility of his scheme seemed so self-evident that I could not frame the terms to disprove it. It was like being asked to prove that the sky was blue: all I could think to do was to point and say, ‘But look.’

At last I said, ‘What about the style? I mean I like to think I’m a good draughtsman, and I’m flattered you think I’m up to Picasso, but really—’

‘That is the simplest part of all,’ Francis said, and clapped his hands in front of my face as if summoning a genie. The bundle stayed balanced in his left orbit. ‘The picture is exquisite, certainly, but composed of no more than fifty continuous pencil lines. It is a sketch, without the complexity of brushstrokes or texture. All you have to do is practise, copy, trace, copy, until you have the movements stored in your brain, until you could reproduce it blindfold. Imagine the kind of people who actually get to see this painting: students in dingy rooms, with no more sense of a picture’s authenticity than you or I have. Do you really think some eighteen-year-old student will have such an intimate knowledge of Picasso’s pencil strokes as to be able to detect the difference? Or is it the bedders you’re worried about?’