Ferox smiled at him. He was an old man with long hair and beard that were white except where the hair was greasy or stained with dirt. Ferox stood up straight and tried hard to look him in the eye, but his sluggish mind took a while to recognise the beggar he had seen at Vindolanda, and then only because of the little mongrel, rubbing against the old man’s legs. ‘It is a blessing,’ he said.

‘They call you Flavius Ferox,’ the old man asked, ‘but what is your real name, Prince of the Silures?’

‘If you know anything of my people, you know that I will never tell you that.’ Every Silurian boy was given a name three weeks after birth, a secret name known only to the closest family and never used except in silent prayer for their protection.

‘I do know your people, and I knew your grandfather. I was there when the Romans killed your father and left his mangled corpse in the surf, blood soaking out into the pebbles. I was there, boy, and I know that you are still of your people and not of Rome.’

Ferox did not reply and stared at the puddle he had just made. He had finished so began fastening everything back into place. He did not want to think about what the man was saying, or how he knew such things.

‘I remember you as a boy,’ the old man said, ‘sitting with the others and listening to Diviciacus drone on.’ A noise more cackle than laugh, and even more like someone choking than either, was presumably the sound of merriment. ‘He was an old fool even when he was young, but a druid nonetheless, and fit to teach infants.’

The memories came flooding back. Diviciacus was a Gaul, who had come to Britannia to study, and missed the slaughter of the priests at Mona so never completed his full training. Ferox’s grandfather had liked him, and entrusted him with the education of the children in his family. For reasons Ferox had never understood, the druid was ordered to teach him – and only him – to speak, read and write Latin.

‘It was a long time ago in a different world,’ Ferox said at last. The old man watched him as if reading every thought. Diviciacus was a mild, worried man, and the children had played many tricks on him, but every now and again another druid had appeared, young, but with a voice full of power and horror. The two men knew each other, and whenever the druid appeared the tutor let him speak to his charges. A name rose from distant memory – a name the children had used to frighten each other.

‘Acco?’

‘You remember then,’ said the old man. ‘Then remember the truth of who you are. You are of the tribes, boy, not a lackey to an emperor. Join us.’

‘Us?’ Ferox did not look up.