‘And then things will not go well for him.’

‘As you say, things will go badly for Saurmag at my hands.’ Azo’s eyes were dancing. ‘There was another I had intended to suffer. But a man who helped put the diadem on the king’s head should perhaps be allowed certain intimacies with the royal family.’

Ballista said nothing. Your whole family is rotten to the core, Ballista thought.

‘Your own household is waiting for you in the fort,’ Narseh said.

‘You took your fucking time,’ Calgacus said.

‘How was it?’ Ballista asked. They were alone on the steps of Cumania.

‘I have had better times. At first Azo hardly spoke. But since a Suanian sneaked into the fort a few days ago with the news that you and Narseh were coming, the little shite has never drawn breath. He has an inventive mind when it comes to torture. Good job he has got used to the idea of you fucking his sister.’

‘How are the others?’

‘Waiting inside. Young Wulfstan is strong. Hippothous is off his head – does nothing but stare at people and mutter about physiognomy telling him the future. Fuck me, another few days and I would have had to kill him.’

The eunuch Mastabates came down the steps. He had a gold-trimmed ivory codicil in his hands. ‘ Ave, Marcus Clodius Ballista, Vir Ementissimus.’ He spoke formally in Latin.

‘What is that?’

Mastabates handed it to Ballista. ‘Your new mandata.’

‘What?’

‘Your new mandata. Signed by the hand of the pious, invincible Augustus Publius Licinius Egnatius Gallienus himself.’

‘How did you get this?’

The eunuch said nothing.

‘You have had it all the time?’

Mastabates acknowledged this with a dip of the head. ‘My instructions were to give you this when your mission in Suania was complete.’

‘And it is?’

‘Without doubt. The first task was to ensure that the nomads were contained beyond the Caspian Gates. That you accomplished today. But the other half was to win back the peoples of the Caucasus to Rome. There is a Persian army at the Gates. The kings of Albania, Iberia and Suania have never been more under the influence of the Sassanids. You, Rutilus and Castricius can hardly be said to have succeeded. Still, you have not failed as spectacularly as the noble senator sent to Abasgia.’

‘What happened to Felix?’

‘He has been expelled from Abasgia for being an accomplice to attempted murder. He is lucky to be alive. My colleague Eusebius was apprehended trying to kill King Spadagas.’

‘Why?’

Mastabates gave a thin smile. ‘What would you do to the man who castrated you for money?’

‘He did not succeed?’

‘No, but he died well.’

‘Did Felix help him?’

‘I very much doubt it.’

Ballista opened and read the codicil. ‘The Heruli?’

‘Yes.’

‘I have to go to the north-east of the Black Sea, beyond Maeotis?’

‘Up the Tanais river.’

‘Out on to the sea of grass?’

‘A not altogether pleasing destination,’ Mastabates agreed. ‘But you will have Castricius and Rutilus as companions. And, I fear, I am ordered to accompany you.’

‘Why?’

‘His imperial majesty did not divulge his thinking to me, but I assume that you, like an Abasgian eunuch such as myself, are supremely expendable.’

Pythonissa came to the chamber at the top of the fort of Cumania where Ballista was going to spend the night. This time there were no carpets, no flirtatious subterfuge. She dismissed her men outside, walked in and told Wulfstan to leave. The boy had been bandaging Ballista’s various grazes from his fall. She did not offer to take over.

‘When did you intend to tell me?’

‘Tomorrow,’ Ballista said.

‘When are you leaving?’

‘Tomorrow.’

‘Take me with you.’

Ballista had been dreading this since he had been given the mandata. If he were honest with himself, he had been dreading this since the start.

‘No. I have a wife.’

‘Take another wife.’

‘It is not permitted among my people.’ It came out easily. It was close to the truth. He had rehearsed it.

‘I have read Tacitus. Leading men among the German tribes can have more than one wife.’

‘I am not a German any longer. I am Marcus Clodius Ballista, a Roman equestrian. I live in Sicily with my wife. Romans have one wife.’

‘Gallienus has taken a second wife.’

Ballista smiled – rueful, placating; he was not sure which. ‘Emperors do not encourage their subjects to follow all their practices. Anyway, Pippa is not a wife but a concubine.’

‘Take me with you as a concubine.’

‘It would not answer. You would not be content. Anyway, I am ordered to travel to the nomads.’

Pythonissa came close. ‘Take me with you.’

‘You will be better here. Without your help, your brother would not have reached the throne. He will be grateful, find you the sort of match you seek.’

Pythonissa waved the idea away angrily. ‘Gratitude does not run in my family. Take me with you.’

‘No.’ There – it was said.

‘I saved your life.’ Her blue-grey eyes looked into his. ‘I love you.’

‘There is nothing to be done.’

She stepped away – tall, straight-backed, angry. ‘They told me you were sick on the battlefield. Did you think I had poisoned you?’

‘It crossed my mind. I thought my usefulness might have ended.’

‘I wish I had.’ She turned and left the room.

Under a lowering sky, Ballista led the small column south up the pass towards Dikaiosyne. It was an oddly assorted company: six fighting men in Roman armour, three eunuchs, eight slaves and a Suanian called Tarchon who would not be left behind – eighteen horsemen with five baggage animals.

It was raining. Groups of Sassanids paused from the grisly work of sorting cadavers and watched them pass. Nothing was said.

The path ran through the village. The horses stepped carefully in the mud of the alleys. The blank, forbidding walls of the towers were black in the rain. They came out into the village square. She was there. Dressed in black, standing in the rain, hair unbound. Standing by the Mouth of the Impious.

Ballista reined in.

Pythonissa did not look at Ballista. She stretched her hands down to the earth. ‘Hecate triple-formed, who walks the night, hear my curse. Vengeful furies, punishers of sinners, black torches in your bloody hands, hear my curse.’

Now she turned her blue-grey eyes on him. ‘Kill his wife. Kill his sons. Kill all his family, all those he loves. But do not kill him. Let him live – in poverty, in impotence, loneliness and fear. Let him wander the face of the earth, through strange towns, among strange peoples, always in exile, homeless and hated.’