‘That’s soldiers for you,’ Brigonius said. ‘Their work is solid and fast, but it’s always functional rather than elegant.’

‘Perhaps, but look around you! This is more than a wall, Brigonius. It is like one immense town that stretches eighty miles from coast to coast. I live in Rome itself and have never seen anything like it - I daresay there is nothing like it in all the world. But here it is in Britain, and you built it, Brigonius. And even when Rome is gone - oh, don’t argue, our Emperor, who rules the wreckage of vanished empires himself, has a profound sense of the mortality of all things - even when the Romans are forgotten this Wall’s mighty ruins will strike awe.’

He said impulsively, ‘You know, you remind me of your mother.’

She shot him a look of suspicion. ‘What do you mean by that?’

He held up his hands. ‘Only her best qualities. When we first rode up from Rutupiae together - do you remember? She spoke to me, and it was as if I was seeing my own country through her eyes. So it is now with you.’

She pursed her lips. ‘I think you’re trying to compliment me.’

He sighed. ‘But that woman keeps coming between us, doesn’t she?’

‘Yes, she does. Shall we ride on?’

They walked their horses further along the line of the Wall, and the sun rose steadily into the sky. Brigonius talked of his wife, his boys; she spoke of her own children who were growing up in such unimaginably different circumstances. And they spoke of old times, of Karus, long retired to Camulodunum - ‘I’ve had enough of history,’ he had protested, ‘all I want is life!’ - and old Tullio, who had completed his twenty-five years in the army, filled a sprawling farm with a brood of red-haired grandchildren, continued to use his own mighty cock as a reference-point in every conversation, and died peacefully in his bed.

They halted on another bit of high ground, overlooking still more of the Wall as it marched on out of sight.

‘You told me before that it felt as if I still belonged at your side.’

‘You said it for me,’ he reminded her gently.

‘You thought it, though.’

‘That’s true.’

‘And do you still think so now?’

He said honestly, ‘I don’t know. Too much has happened.’

‘Yes. For us to be together the tapestry of time would have to be unpicked and woven again - wouldn’t it? Perhaps if I had stayed in Brigantia all those years ago, rather than leaving with my mother. Or if you had given up all this to come with me to Rome.’

He shrugged. ‘What’s the point of speculating that way? You can’t change history.’

‘No. But, Brigonius - what if you could? For that is what my mother believes is the meaning of the Prophecy.’