They kept to the high ground, and could see the east–west road below them, sometimes as close as half a mile, more often further away. There were a few travellers along this route, but most of the traffic was military. They passed a couple of carts going westwards at the plodding pace of draught oxen, and three score of pack mules escorted by a dozen legionaries with as many slaves to tend to the animals. The sight made Ferox think, because the convoy would have made a prime target for raiders wanting to take some heads and get some loot.

Vindex must have had the same idea. ‘Perhaps they were lucky and got through before the ambush was ready?’

‘Perhaps.’

Half an hour later they passed Vindolanda, its buildings a dull white in the distance, and Ferox hoped that the curator was well on his way to the fort. Victor ought to have reached the tower by now, but there was no sign of the beacon’s warning smoke. Another mule convoy passed by on the road, bigger than the first, but still vulnerable to a determined band of fifty or sixty men – assuming they had not been joined by yet more warriors.

Ferox put his horse into a canter and drove the beast hard, slapping with the flat of his hand when the gelding tried to slow. They raced along, the horses’ shoulders and flanks white with sweat, eating up the miles until they could no longer see the fort, but only the thin tendrils of smoke from its fires. The gelding was breathing hard and beginning to stumble, always a sign that the animal had little more to give. Ferox slowed them back to a walk.

‘That’s where I would do it.’ He pointed ahead. The road veered a bit to the north, running along the valley side to follow a much older trackway and avoid meadows that became bogs after just a couple of days of rain. For a mile or so it was less straight, allowing wagons to negotiate a succession of little slopes and gullies. There were scattered copses and a couple of large woods, the trees big and offering plenty of cover from prying eyes. One stretch went along the bottom of a little valley and was even more secluded.

Vindex snorted with laughter. ‘Trust a Silure to pick the right spot for an ambush. Bandits the lot of you.’

‘They say I am a Roman.’

‘So they say.’

There was a murmur from the scouts, making Vindex turn in the saddle. ‘Beacon’s lit,’ he said.