‘Have you three lost your minds?’ Valens snapped. ‘There are no soldiers here, but there are tens of thousands in Persia. We are hundreds of miles from our objective.’

They stared back at him.

Valens rounded on Clemens and Hairan. ‘You will have done worse as . . .’ he checked himself, avoided the word frumentarii ‘. . . in your duties.’

Both men looked at Iudex.

‘As for you, Iudex, an oath taken under duress is no oath at all. Your god will absolve you.’

It was difficult to face down the huge bald man.

‘We are merchants, not an invading army. We must behave as such.’

The small childlike features regarded Valens with great solemnity.

‘Everywhere, custom is king. Kiss the fucking thing!’

With no expression on his face, Iudex did as he was told.

One by one, with more or less evident reluctance, every man did the same.

Last of all, Valens bent and put his lips to the image.

‘It is all good, my friends.’ The eunuch was beaming with relief. ‘All very good. At the edge of the village is a caravanserai. It is basic for such honoured guests, but it is clean, and the food is excellent, and they tell me that the girls are skilled.’

The cameos were wrapped and packed away.

The eunuch quickly wrote a note, recording them as a merchant caravan that had paid the import duties and was bound for Hyrkania, which he presented to Narses.

‘You can get provisions in our market – wine, venison and bacon, leavened bread and vegetables, palm dates like amber. You must stock up. The land downstream is full of wormwood, everything that grows there is bitter. There are few villages there, and the people are thieves.’

As the fat official prattled on, Valens still felt the cold press of the metal on his lips. If the gods existed, they had no interest in mankind. There could be no sacrilege. Yet somehow he felt vitiated, as if he had betrayed some part of himself.

*

Valens lay back on the narrow bed. The cheap, stained sheets were rumpled.

Alexander the Great had said that only sex reminded him that he was mortal.

The girl ran her palm across his chest, murmuring incomprehensible endearments or compliments.

Her skin was brown, smooth like silk, her dark nipples almost as black as her hair. The first coupling had been brief. It was a long time since the girl in Resaina. In the second, she had feigned pleasure.

Now Valens felt an overwhelming urge to get away, to be downstairs drinking with his men. He removed her hand, and got up. Finding his wallet, he gave her a few extra coins as a tip. When she spoke her tone sounded grateful, but he could not tell if she murmured thanks or was cursing him.

‘Our officer returns.’ Clemens was in fine humour, his air of archaic republican morality set aside for the evening. The armourer flourished his cup, and recited a poem in Greek.