Hairan twirled the points of his long moustache. ‘An open road, the wind in your face, a sword on your hip, a woman in your bed, a poem in your heart – adventure is in the blood of the warriors of Hatra – although there are few women in this desert. Perhaps in Persia . . . Have you ever had a Persian?’

‘No.’

‘You should, they are very lascivious. And a few nights with a houri does wonders for learning a language. Although much of what they say is not polite.’

They had not been searching long when they found Valens’s horse and one of the missing mules at no great distance. The horse was sheltering in a small depression. The mule was standing in the open, enduring with the eternal patience of its kind. But Quintus’s mount and four of the mules were gone beyond recall. As bad luck would have it, one of the lost mules had been carrying half the trade goods.

‘Some tent-dweller will find a fortune,’ Hairan said.

‘Perhaps the bones and the jewels will lie undisturbed forever,’ Valens said.

‘Or some traveller will stumble across them in centuries to come.’ Iudex narrowed his eyes, as if peering far into the future. ‘Long after Rome has fallen, they will hold those artefacts in their hands, and wonder at the pointless ingenuity of the artists who expended such time and skill in carving tiny figures in gemstones, condemn the vanity of those who desired such things.’

‘You do not believe Rome to be eternal?’ Valens asked.

‘Nothing is eternal, except Light and Darkness,’ Iudex replied.

As the merchandise was easily portable, Valens decided to redistribute the remainder in the saddle bags of the eight surviving members of the expedition. That an individual might desert crossed his mind for the first time. Once the idea was there, it seemed extraordinary that he had not thought it before. The three easterners could be most tempted. They were closest to home. Although, of course, Hairan’s city of Hatra was no longer inhabited. But all frumentarii were selected for their resourcefulness. Any of them could decide to vanish. It would not be difficult to make a new life somewhere in the vast expanses of the empire, or even beyond its frontiers. The price of the cameos would set a man up, if not for life, at least for a time. Yet Valens thought sharing out the valuables a risk worth running. If all the trade goods were lost, it would be hard to pretend to be nothing more sinister than a merchant caravan.