‘By the gods, who are you?’ In the face of the armed men, and Narses’s assured intransigence, the tone of the eunuch had changed to a whine of entreaty.

‘Since you asked me with politeness this time, I will tell you. I am Narses, son of Rastak of the Suren, caravan guard in the service of Marcus Aelius Valens, merchant out of Antioch. We carry carved gemstones and jewellery to trade in Hyrkania.’

As if by magic, the attitude of the eunuch became civil, even obsequious. Although a gleam in his eyes indicated this might have been caused by him scenting his own perquisites on these valuable commodities.

‘If you would be so kind as to accompany me to the customs house.’

Inside the building, the merchandise was brought out. In the negotiation, Narses was gracious but firm. The tax across the border was set at twenty-five per cent, the highest known in the world. A contribution to the official brought the sum down.

Even when Valens had handed over the money, the business was far from over. Through Narses the eunuch asked each man his name and family, what was his profession, from where he came, and his reason for travelling. As there was no reason not to, they gave their real names. The official wrote everything down in a book, although all the answers except the names were the same. It seemed to take an inordinately long time.

‘He is recording our dress and appearance,’ Hairan quietly told Valens. ‘They will be passed on to the Ears of the King – the Persian King, like the Roman Emperor, has those who watch and listen.’

‘One last formality.’ The eunuch went to a sort of shrine, and brought back a small statuette. It was made of gold, and looked incongruous in this poor village.

‘What is this?’ Hairan asked.

The eunuch looked surprised that another in the party spoke his language.

‘Shapur the King of Kings has decreed that everyone entering his territory must pay their respects by kissing his image.’

‘Romans are exempt from this ceremony.’ Hairan said with finality.

The official wrung his hands apologetically. ‘Only envoys from the Roman Emperor.’

When Hairan translated the exchange, Clemens bristled. ‘A free man only gives such a tribute to a god.’

Unexpectedly, Iudex also refused. ‘It is anathema in the eyes of the Lord to venerate idols.’

‘They are right,’ Hairan said. ‘I will not abase myself to an image of that murderous bastard.’

Although unable to follow the Latin words, the eunuch understood their refusal. ‘It is the law. Anyone has to be arrested with dishonour unless he pays honour to the image.’

‘Never,’ Clemens said.

‘It is an abomination,’ Iudex said.

‘There are no soldiers here,’ Clemens said. ‘We have nothing to fear from this excuse of a man.’

‘Fuck the Persian bastard,’ Hairan added.