Rolt was on his feet. He shook the hand of the interviewer and turned. The cold, focused gaze melted when he saw Tom. He strode towards him, hand outstretched. ‘I didn’t think you’d come.’

‘Why not?’

Rolt’s hand wrapped itself round Tom’s. ‘An old schoolmate calling out of the blue – who needs that?’

They both laughed.

‘And with all that’s going on.’

‘I was very sorry to hear about your people.’ They shared a moment’s silence before Tom continued, nodding at the TV crew packing up, ‘I see you’ve not lost your taste for a fight.’

Rolt gave Tom a knowing smile. ‘Nor you, I hear.’

There was a note of compassion in Rolt’s tone. But Tom ignored it. He had other reasons for being there.

Phoebe came and stood by Rolt’s elbow. ‘Perhaps you’d like to get away from this lot. Why don’t you go through to the office and I’ll fetch some tea?’

Rolt showed Tom the way down the hall. The office was impressive, with floor-to-ceiling windows that looked out onto St James’s Park. It must be costing him a fortune. And that livid skyscape of red and orange over the fireplace. Was it an original?

‘Don’t tell me that Turner’s real?’

‘Isn’t it a beaut? They used to think it was pigment degradation. Now it’s believed the colours are accurate – refraction by volcanic ash in the atmosphere.

‘There were three eruptions in his lifetime, Tambora in 1815, Babuyan Claro in the Philippines in 1831 and Cosigüina in 1835. Not that Turner knew.’

‘So you were paying attention in class all along.’

‘I think it got in by osmosis. No actual effort on my part.’

Tom turned back to the painting.

‘Tambora spat an estimated twelve cubic miles of magma into the atmosphere. There was so much ash in the atmosphere they called 1816 “The Year without Summer”.’

Rolt beckoned him to turn round. Hanging opposite was a huge faded tapestry, with the faint images of figures visible in the weave. ‘It predates Bayeux. I found it at an auction in Texas. God knows how it fetched up there.’ Rolt pointed at the standard bearing the word ‘Invicta’, held high by solid yeomen, the cliffs of Dover beneath them.

Tom had also remembered something from school. ‘Undefeated – Roma Invicta. The Romans had it stamped on their coins to boost morale when the empire was on the wane.’

Rolt smiled. ‘Correct. And much later, when William defeated Harold at Hastings and set his course for Winchester, these men of Kent, a few with swords but most armed with no more than wooden staves, marched against him. William saw their determination and knew they would fight to the death, so he offered them a deal: safe passage for his army and in return the men of Kent would keep their ancient rights and liberties. Hence “Invicta” became the motto of the county.’