‘Huh.’ She raised her eyes to the sky. ‘Well, of course I must believe you.’ She stared at him straight-faced, and then laughed that rich, musical laugh. ‘Nearly home,’ she said, a moment later. ‘So I had better become the great lady once more.’ Sulpicia Lepidina gave him a stern look, lips pursed in exaggerated distaste as she glanced down at his mud-stained cloak, and then with a jerk she pulled the curtain closed.

They were through the canabae and approaching the main entrance to the fort. Compared to Syracuse it was massive, with double gates each high enough for a horseman not to have to lower his spear and wide enough to let a big wagon – let alone the raedula – through, or a rank of men pass four abreast. The rampart of the turf wall with its palisade on top was fifteen feet high and the wide tower over the gateways was as high again, although it was not roofed. Ferox could see a pair of sentries standing miserably on the platform on top. Vindolanda was in the process of being rebuilt for the second time in less than a decade, mainly because the previous fort had been thrown up too quickly for it to last.

A file of sentries straightened up, spears held perfectly straight to salute the passing carriage. One of the men stepped forward in a less welcoming manner as Ferox, Vindex and Philo walked their mounts forward, coming level with the deep ditch on either side of the road through the gates.

‘Flavius Ferox, centurio regionarius.’

‘Sorry, sir. Didn’t recognise you, sir.’ The man stiffened to attention, without quite matching the respect shown to the commander’s wife. ‘And your party, sir?’

‘Vindex, son of the high chief of the Carvetii and commander of the scouts that serve alongside us, and Philo, scholar, philosopher, doctor and teacher from the great city of Alexandria.’

The senior soldier knew when an officer was having his little joke. ‘Yes, sir. Very good, sir. I’m sure you know best, sir. Officer and two others to pass!’ he shouted up to the sentries in the tower. ‘Use the right-hand passage if you please, sirs,’ he added.

Ferox also knew the signs and could see the big puddle and churned mud in the middle of the road behind the open gate. ‘Let the horses walk two paces then canter through,’ he whispered. Vindex followed his lead, kicking his horse so that it surged forward. Philo was confused, and when he kicked the mule the animal bucked and threw him. The other two just made it through before a jet of water shot down from the underside of the rampart. Ferox guessed that there was a gutter leading from the open platform to funnel the rain downwards and that the men on top had opened a little sluice.