‘Good manners are important,’ was all that he said afterwards, although that may have been because he was feeling a little the worse for wear after downing several wooden cups of beer. The Batavians had sucked the liquid down like sponges and after initial suspicion had greatly enjoyed being chosen.

The next day the tribune had a green pallor and Ferox was spared questions for the first few hours. The respite was temporary. ‘Why do the houses have doors facing south-east?’ ‘Why no chimneys?’ ‘Were those people from a certain clan and how can you tell?’ On and on, until the centurion set off to visit the scouts. Crispinus was only prevented from going with him when Masclus insisted that as commander of the escort it was his job to ensure the tribune’s safety and that would not be easy if he started gadding about away from the column.

Two more cold nights were followed by bright days with only gentle winds and the tribune talked about how everyone exaggerated the savagery of northern climes. They passed the great trading post of the Votadini, a walled stronghold and market on a great hill that rose above miles and miles of gently rolling pastures. Ferox had been there a couple of times and often seen the place from afar. It always reminded him of a painting he had once seen of the pyramids in Egypt. They did not go close, for it was out of their way, but he could see that even Crispinus was impressed.

‘Never expected to see so many people up here,’ he said, shaking his head. ‘There are farms everywhere, villages, well-tilled fields and fat cattle and sheep.’

‘What were you expecting, my lord?’

‘More of a wilderness – marsh and dark woods.’

‘Well, there’s some of that, to be sure, but hopefully we won’t need to go through it.’

They kept going, until the crest of a rise gave them a view of the estuary of the great river opening out into the sea. The water sparkled in the morning sun, white-capped in places for the wind was blowing strong and bitter cold from the east.

‘“Thalassa! Thalassa!”’ Crispinus proclaimed at the sight. Ferox felt his heart lift, but he was thinking of his own homeland more than Xenophon and his Ten Thousand mercenaries glimpsing the sea that led them home to Greece. The water up here was a clear blue like glass, not like the muddy brown of the channel near his homeland, and yet its moods were the same. He caught the faint hint of salt on the air and it made him yearn for the simplicity of his childhood when no oaths bound him tight. Here he was, several days’ ride beyond the furthest outpost of the empire, and he still felt confined. More than once in the last days the tribune had asked him why he stayed in his out-of-the-way post.