Volisios frowned. Aged perhaps forty, some ten years younger than Thalius and Tarcho, he was a small, rotund man with shaven head and plucked eyebrows - an oily man, Thalius thought, slippery. He clearly didn’t know what to make of Thalius, and his story of looking for a particular slave boy. Why would one of the curia of one of the most significant towns in all four Britains come to a place like this, if not to spy, sniff around, look for evidence of tax avoidance and other evasions? And so he squirmed and wriggled as he sought to conceal the petty graft Thalius had no doubt existed. Volisios said, ‘You must understand that the workers wouldn’t be here at all if they weren’t scum, or the spawn of scum - and it’s the devil’s own job to keep them in order.’

Tarcho grunted. ‘And it looks as if the devil has had his hands full.’ He pointed.

On a ridge close to the fort Thalius saw a row of crosses, each eight or ten feet tall, stark shapes silhouetted in the afternoon light. Rags appeared to be dangling from their frames.

‘You can see from the state of those corpses that it’s a while since we had any trouble, and just as well for my purse.’ Volisios began to talk of the cost of the last petty uprising. Those who ran this mine did so under licence, for Dolaucothi was an imperial estate, and from their profits its managers had to contribute to the upkeep of the fort and its soldiers. ‘We even pay for the wood on which the miscreants are crucified,’ he grumbled. ‘But we get by. I’ve run this mine for twenty years, as did my father, and his father before him ...’

It was a typical story. Many professions had long been made hereditary, as had Thalius’s own position on Camulodunum’s curia. People joked that everybody took his father’s job nowadays - everybody but the emperors, who killed other people’s fathers to take their job.

‘My father worked this place in the time of the Emperor Carausias,’ Volisios went on. ‘He kept working right through the time of the Roman Invasion too. That didn’t bother him, but he never got over the way the taxes were hiked up afterwards!’

‘Carausias was no emperor but a usurper,’ Thalius felt compelled to remind him. ‘The purpose of the Invasion was to remove him. And of course taxes are higher now. Things have changed since the days of Hadrian, you know.’

Volisios looked confused. ‘Who?’

‘An emperor from ancient history,’ Tarcho said. ‘From a hundred years ago!’

‘More like two hundred,’ Thalius corrected him mildly. He pointed. ‘You’ll have to take those crosses down. The Emperor has banned crucifixion.’

‘He has? Why?’

Tarcho said heavily, ‘Why do you think? Because the Christ was executed on a cross.’