‘There was a Peter Cook sketch once,’ said Cooper. ‘From the Footlights, maybe: “When the four-minute warning sounds . . .”’

‘“. . . hold your breath and jump into a paper bag.” Yes, I remember.’

‘The Government’s preparations for nuclear war were ridiculed, weren’t they?’

‘Well, I blame the media for that,’ said Headon. ‘The public got the idea that if there was a nuclear attack, everyone would be wiped out and there’d be nothing left except some kind of radioactive wasteland. That’s why the advice sounded ludicrous. But if people took sensible precautions, most of the population would have survived an attack. You just had to make sure you stayed indoors until the fallout dispersed.’

‘If you say so.’

‘It’s true.’

Cooper had grown up accustomed to the idea that history was all around him – many thousands of years of history, right there, visible in the Peak District landscape. Stone circles and Iron Age hill forts were curiosities to be explored, the bumps and hollows of ancient lead mining added an intriguing feature to many parts of the county. Tudor manor houses and the vast mansion of the Dukes of Devonshire at Chatsworth were obvious historical landmarks. Eyam itself was a monument to a seventeenth century disaster.

But more recent history was sometimes overlooked. Apart from the Dambusters museum at Derwent Reservoir, there was precious little to remind people of the events of the Second World War. And the Cold War, even less.

Perhaps it was because those events were still within living memory for so many people. The years when the world was on the brink of extinction didn’t need a museum or visitor centre, because they were still clear and vivid in the minds of those who’d lived through them, and survived. Well, it was only true of the older generation now. Cooper couldn’t recall being taught many details about the Cold War when he was at school.

But then he thought about the dates again. Of course, the Cold War had still been going on when he was a child, with the likes of Reagan and Thatcher rattling their sabres at the Soviets. All through the nineties, new Trident submarines were still being rolled out. What were they called? Vanguard, Victorious, Vigilant. They sounded much like the names of foxhounds, really.

In 1991, John Major had been in his first year as prime minister, and George Bush Senior was still president of the USA. The pre-Blair, pre-Clinton years. It seemed like a millennium ago.

‘So, 1991 . . .’ said Cooper. ‘The Soviet Union collapsed. The Berlin Wall had come down . . .’

‘Yes, and suddenly there was a big hole in the nation’s defences,’ said Headon. ‘That September, our Chief Observer had a letter asking him to arrange the clearance of the post, and return the equipment and keys. It was adding insult to injury. Frankly, we told them “sod that”. They could collect the stuff themselves. And that was the last we heard from the ROC.’