‘He had help from someone important,’ Ferox went on, looking now at Flaccus. ‘A senior officer in one of the legions. On the day of the ambush he betrayed the Lady Sulpicia, letting the rebels know about her journey. But someone else arranged for soldiers to go to the tower and murder our own men so that they could not light the beacon and raise the alarm. The men who did were legionaries, and they bore the symbols of the Augusta, but that was a ruse to throw us off the scent. Same when some of the men were at Vindolanda at Samhain.’

Ferox kicked Crispinus again. ‘Talk, you mongrel.’

Crispinus moaned.

Ferox spat on him. ‘I’m afraid that the murderers came from the Ninth.’

Flaccus’ hand gripped his sword, but he did not draw it.

‘Did you know they raped that poor woman before they killed her?’ He invented the detail on the spur of the moment. Given the state of poor Fortunata’s body, there was no way to tell. ‘All of those Roman soldiers took turns and then handed her across to the rebels for them to torture.’

There was a flicker of surprise in the junior tribune’s eyes, but although Flaccus glanced at the soldier with the drawn sword, he said nothing.

‘I will need your help to find them, my Lord Flaccus. And to find the officer who led them. I suspect one of your centurions, although the man dressed as a tribune to confuse us. Will you help me?’

Flaccus’ hand stayed on his sword, but he seemed to relax a little. ‘Of course, centurion, although with so little to go on it will not be easy.’

‘Ah, but we have a witness.’ Ferox turned away and looked north towards the hills above the ferry crossing. ‘He’s late, but should be here soon. The survivor from the attack on the tower. No. No sign of him yet.’ Ferox turned back and smiled. ‘He did not get a good look at the officer, but he claims he saw some of the soldiers clear enough to recognise. We can find them, I am sure.’

Ferox strolled towards Flaccus. ‘You may as well have your man kill him,’ he said mildly. ‘I don’t think he is going to talk.’

‘Do it.’ Flaccus told the soldier with the drawn sword. ‘Make it clean.’

Ferox watched the man pace over to Crispinus, who did his best to roll away. Flaccus sneered and shook his head. ‘A nobleman,’ he said sarcastically, and then Ferox swung his blade up and jabbed straight into the junior tribune’s throat. Flaccus’ eyes widened, blood jetting from the wound as the centurion pulled his sword free, stamped forward and drove the point through the eye of the legionary standing behind the officer.