The real limiting factor, as Francis taught me, was imagination. He argued that the vast majority of people failed to find joy because it never occurred to them to look. It was not only the depth of creative thought, but the direction in which that thought was employed that marked Francis out from the other people I had come across in my life. He was not confined to dreams, to financial or romantic intrigue or even to art – his fantasies were omnivorous. This was the real reason Francis climbed; it was a model of his interaction with the real world. Where the rest of the passing pedestrians saw only a door or a window, Francis saw a fingergrip, a foothold. He thought in different dimensions, and he applied to the buildings a new set of rules in opposition to the strict proportions that dictated the classical façades or the judicious physics that maintained the Gothic fan vaults. His imagination swarmed over them. He had the habit of recognizing possibilities in everyday scenes, so that even as we strolled down the street he would be checking pipes, roofs and railings for possible points of ingress. He was truly unique in this, and it made me feel privileged to be in his presence. I tried to understand the way he saw things, and to incorporate something of his vision into my sketches, so that my work began to grow. My pictures became not merely accurate renderings, but interpretations, and I even made myself thrill with pleasure at my finished pieces, though I showed them to no one. When Francis spoke and plotted, I sometimes felt like a scribe, privileged to follow and record for posterity. In this I was my own audience too, and I would never sleep the morning after a climb, but lie awake as the sun rose and repeat to myself something he had said or done, puzzling out the meaning.

My memory of those climbs is a montage, a blend of similar but distinctive experiences amounting to a kind of advertisement for living passionately. I remember standing with the statues of saints on their pedestals above the Wren Library looking over Tudor Great Court, and clasping my legs around the pinnacle of the lightning conductor on the dome of St John’s, spreading my arms in the void as the sun rose. But I know the climbs themselves were authentic – the exhilaration was real, and left no room for self-consciousness. We began on small and distant buildings, climbs that were both simple and removed from the city centre where the streets were never entirely empty, even in the hours before dawn. If I had any doubts that these choices were made with me in mind, they were dispelled by Michael talking of the time when they could ‘take off the training wheels’, and return to the more interesting haunts near King’s Parade. He was in his element on these climbs, and his boisterous success was almost as effective in driving me as Francis’s careful tuition; I could not stand to come over a lip of brick at his feet, to find that he had already controlled his breath whilst I panted with exertion. Despite our best efforts we were sometimes spotted on the faces of the buildings, and our night would end with a brief and wild chase like the one that first guided Michael through my window. The porters never won, because they could not match our willingness to take risks.