Inside the room, his friend was already asleep, still in his borrowed robes, head resting on a bolster and mouth agape as he breathed heavily. Macro smiled. Cato had beat him to it, keen to fall asleep before Macro’s snoring could keep him awake.As Macro kicked off his sandals he noticed that Cato still wore his. He hesitated a moment, then padded over to his friend and pulled the sandals off gently and placed them on the floor. Then he lay down on his own bed, smiling at the comfort afforded by the thick bedroll. In the background the water gurgled pleasantly and dappled sunlight filtered through the foliage on the trellis. Macro closed his eyes. He could do with a few days of this, and he found himself hoping that the King of Nabataea did not return to his capital too soon.

As his thoughts returned to the reason for their presence in Petra, Macro’s mood soured. Somewhere out there in the streets and houses of the city lurked Bannus and his Parthian friends. Whatever the King decided to do on his return, there would be a reckoning, Macro vowed. Bannus must not be allowed to survive and breed yet more rebellion in the troubled, long-suffering province of Judaea.

The days passed slowly and Cato and Macro quickly grew frustrated by the restrictions placed on their movements in the city. Especially Cato, who was fascinated by the sheer peculiarity of the vast tombs and temples that had been carved from the rock with such skill. By day they explored the market, and marvelled at the range of luxury items that rivalled all but the most prestigious establishments in Rome. There was a library where Cato discovered a collection of maps, many of which detailed lands that no Roman had heard of, let alone seen. For his part, Macro was content to sample the food and the wine and catch up on his sleep in the cool garden of Symeon’s house. Soon after their arrival Symeon informed them that he had discovered where Bannus and the Parthians were staying. A rich merchant on the other side of the city had offered them his home. He had no love of Rome, like many Nabataeans who viewed any expansion of the Empire with anxiety.

Then, one afternoon, when Cato was walking through the precinct of the great temple in front of Petra’s wide forum, Bannus emerged from a colonnade right in front of him. Both men automatically stopped and started to apologise before their eyes met and the words died on their lips. There was a tense silence and then Bannus made to move away.

‘Wait!’ said Cato. ‘I want to talk. We have to talk.’

Bannus continued for a few paces before he stopped and turned. ‘Aren’t you forgetting the terms of the oath we took for the chamberlain?’

‘No. But that was to stop us fighting. I just want to talk.’