A Roman might have been a little different. They always boasted of their willingness to adopt the best of foreign things. But, apart from Greek culture, that really boiled down to weapons and military practices – a Spanish sword, a German war cry, the Punic word for ‘tent’. Ballista would follow them in that. He actually relished the chance to ride with the Sassanid clibanarii and see what war was like with them. And he had the dangerous opportunity to fight the nomadic Alani and see how they waged war.

But Ballista wanted to go further. He wanted to find out how the other peoples he was thrust among did things, how they regarded the world and the things in it. He was not going to fall into the trap of considering the customs of every people as good as each other. The Suani were too murderous; the Persians too god-haunted. But by looking at their attitudes, his own values might come more clearly into focus. The fable told that each man had a wallet on his back containing his failings. Those of others were easy to see; your own very difficult. Maybe exile could provide the chance to sit down, unstrap the wallet, bring it around to the front and examine its contents with care.

Duty, friends, family – in ascending order, Ballista had decided that these were what he was about. Trying not to let any of those three down, trying not to do things of which he would be too much ashamed. Pythonissa slipped into his thoughts. How did she fit into the image he was constructing of a man made better by being refined and tempered by exile? Allfather, what if Julia found out?

The warriors of Hamazasp were waiting for them on the far bank of the Alazonios river. It was a serious levy, twenty thousand or more, arrayed for war. The Iberian king was in the centre, mounted on a black Nisean charger, beneath a great black banner embroidered with a red bull. The men with Hamazasp outnumbered those with Narseh several times.

The Sassanid forces neatly manoeuvred into position: the clibanarii in the centre with Narseh, the light horse on either side, the Albanians out on the right flank.

The two armies watched each other across the water. The Iberians looked much like the Persians. But they were less well armed, and showed less discipline. The Persians sat quiet in their units, awaiting the words of command. The Iberians surged about, horse and foot intermingled. Their nobles caracoled their horses, sang out things in their native tongue.

Ballista spotted the tall, red-headed figure of Rutilus stationed with the nobility near Hamazasp.

Hamazasp and another rider, backed by half a dozen others, walked their horses out to midstream. The Alazonios was the border between Albania and Iberia. It was neutral ground, watched over by the deity of the river.

Narseh told just the mobad Manzik, young Gondofarr, Ballista and Pythonissa to accompany him. Obviously, the veteran Tir-mihr was to take command, should anything happen to the prince. The five riders splashed out into the river. Narseh halted the length of a horse from Hamazasp.

It was for Hamazasp to speak first. The water ran around the horses’ legs. The king of Iberia looked over those with the Sassanid prince. When he reached Ballista, he sneered.

At length, Hamazasp bowed in the saddle, blew a kiss. ‘Welcome the glorious Prince Narseh, son of the Mazda-worshipping divine Shapur, King of Kings of the race of the gods, grandson of the Mazda-worshipping divine Ardashir, King of Kings of the race of the gods, great-grandson of King Papak of the house of Sasan. I, Hamazasp, by the grace of Mazda king of Iberia, and my brother the pitiax, Oroezes, welcome you. How may we and the warriors of Iberia serve you?’

With a slight movement of the head, Narseh acknowledged this. ‘We thank you for the gracious words. In the name of my father Shapur, we wish to cross your land unhindered to drive the nomad Alani back through the Caspian Gates to the sea of grass.’

‘It shall be as you say.’

‘Furthermore, we wish you to provide food for our men, fodder for their horses.’

‘It shall be as you say.’

‘Furthermore, we wish you or your brother, the pitiax Oroezes, to join our expedition with one thousand horsemen, and to take a binding oath to these things.’

‘I will be honoured to lead my men to war with you.’ Hamazasp could not prevent the sly look on his face. ‘All will be as you wish, noble prince of the house of Sasan. But I have a petition. The late King Polemo of Suania unjustly seized territory from Iberia. If his daughter who rides with you will take an oath to return all the land up to the Dareine Pass, my warriors will fight all the more courageously in a just cause with friendship restored between the Iberians and the Suani.’

Narseh turned to Pythonissa. She curtly bowed her head.

Hamazasp took his oath first. It was in the Persian fashion. The mobad Manzik produced the salt, and the king of Iberia swore with his hand on that.

Pythonissa nudged her horse nose to tail with that of Hamazasp. The pitiax reached across her and tied her thumb to that of Hamazasp. The king of Iberia produced a knife. He cut his own thumb, then hers. ‘Neither with steel nor poison,’ he said. Raising their bound hands, he licked the blood from his own thumb then from that of the woman who had once been his daughter-in-law. ‘Sealed and countersealed in blood.’

As Pythonissa repeated the oath, Ballista knew full well that neither of them would keep it.

XXXI

The prince Narseh of the house of Sasan with his warriors and his father’s Caucasian vassals marched out of the north gate of the Iberian town of Harmozike five days before the ides of September. Ballista’s odyssey to rescue Calgacus was going to be decided soon, one way or the other. Yet he feared it may all have taken too long. After they had met Hamazasp down at the Alazonios, etiquette had demanded they remain camped on the riverbanks for two days. First, the king of Iberia had feasted the son of the Sassanid king, then Narseh had returned the compliment. These had been uncomfortable occasions for Ballista. Beyond a formal greeting, he had managed to keep from having to talk to Hamazasp – there were many present – but he could not avoid the Iberian’s glances. The monarch did not attempt to disguise his hatred. Ballista knew the man would like to eat his liver raw.

Another six days had passed as the combined forces wended their way up to Harmozike. There, two more precious days had been consumed by yet larger, yet more extravagant dinners. Wedging himself among Rutilus, Castricius and Maximus, and using Pythonissa as a screen, Ballista again had avoided any conversation with Hamazasp. But in his own residence the king had become bolder, especially when fortified with wine. Several times, Ballista had looked up the hall to realize that Hamazasp was talking about him, laughing with his nobles. Ballista was certain of it. He could not hear the words, but they had glanced over. Had Hamazasp been telling them what he had nearly done to Ballista in the cell in Edessa? Was he claiming more than the truth – claiming that he had gained some revenge for the death of his son by raping his killer? Ballista was furious. If the Iberian said something in Ballista’s hearing, the northerner would have to try to kill him – even though the chances of success were minimal and the likelihood of himself being killed almost certain. But unless that happened, there was nothing he could do.

Pythonissa had said that there was much more than sexual innuendo to be concerned about. Ballista had argued that, as he was doubly protected as an envoy of Rome and a companion of Narseh, the king of Iberia would not dare harm him. Pythonissa’s withering reply had surprised Ballista in the crudity of its language. Did he not understand that they were lodged in the palace? Hamazasp hated him – the northerner had killed his son, and now was fucking his daughter-in-law under his own roof. Pythonissa’s father had not countenanced her remarriage to the old king, but Hamazasp himself had given every indication of wanting to fuck her. Hecate knew, he had tried often enough, in this very building, when she was married to his son. Of course, Hamazasp would not make an overt move against Ballista, just as he would say nothing that Ballista could hear – the Iberian may be a filthy, perverted goat who had tried to fuck his son’s wife – but he was not a fool. Yet had Ballista failed to notice that, in the Caucasus, poison was a way of life? Anyway, she was as concerned for herself as for Ballista. Her relationship with the northerner had made her an enemy in Hamazasp, that and not going to the king’s bed. She had insisted neither Ballista nor she ate or drank anything that had not been tasted by her poor eunuch. She advised Ballista not even to touch anything that others had not already handled. Such procedures were hard to carry out unobtrusively. She did not seem to even try. It had not helped the general atmosphere at court. Nor had Pythonissa’s open nocturnal visits to Ballista’s chamber. At least the eunuch had not died yet.

It was a fine morning as they rode out of Harmozike. The early autumn had taken the intense heat out of the weather. Ballista felt better. He was fully armed and mounted on a good horse – a Nisean stallion lent by young Gondofarr. Ballista’s three Roman friends were around him. They rode at the head of the army, just behind Narseh, well away from the Iberians.

The order of march remained as before, with two thousand of Hamazasp’s Iberians added to the rear. At a last-moment command of Tir-mihr, the rearmost group of Sassanid light horse were divided into two, and one half was placed between the Albanians and the Iberians. Old ethnic animosities might flare at any time. Ballista was confirmed in his admiration for the elderly Persian general.