‘I don’t know,’ Cato admitted. ‘I’ve never thought about it.’

Symeon shrugged. ‘Then maybe you should.’

After Symeon had dismissed his Nabataeans they rode on, threading through the marshalling arena until they reached a broad road that led towards the rock cliffs. The road was paved and gently cambered with a drainage ditch on either side. There was plenty of traffic along the route, more porters, merchants and mercenaries like the men who rode with Symeon and Murad. On either side of the road were tombs, carved into the rock with great skill so that the facades looked like freestanding columns. Then the road curved round a large rock formation and Cato and Macro saw a small but solid-looking gateway built across the road. Behind it soared sheer cliffs of red rock marked with darker and lighter bands of stratification. There was a narrow fissure between the cliffs that led back into the mountains. Symeon turned to his Roman companions.

‘That, my friends, is the siq.’

The gateway was guarded by a score of men in fine robes and polished scale armour that gleamed brilliantly when they stood directly in the sunlight, out of the shade of the cliffs. Before the gate stood a crowd waiting to pay their toll to go through, while a steady stream of people passed by in the opposite direction. Symeon indicated that they should dismount, and led them over to join the crowd entering the siq. The crowd slowly shuffled forward until Symeon approached the table set up by the entrance. A smiling, over-indulged official greeted him in Aramaic.

Symeon responded, indicating the size of his party, and the official quickly rattled some beads across an abacus to work out the toll. Symeon took out his purse and handed over some silver coins, and the official slipped them into the slot atop a big chest to one side of the table. He was about to wave them through when he spotted Macro and Cato and his eyes narrowed suspiciously. He raised his hand to halt Symeon and shot some questions to him in a hostile tone. Symeon responded as reasonably as he could, but the official became increasingly ill tempered and finally shouted an order to the guards by the gate.

Macro stepped towards the table. ‘What’s going on?’

‘Our friend seems to have taken exception to you. There were some Parthians amongst a party seeking entry to Petra early this morning. Now there are two Romans. He wants to know why representatives of the great powers are suddenly so interested in visiting Petra.’

‘But we’re not representatives. We’re just hunting down Bannus. Tell him.’

‘I did. I said I have a house here and that you are my guests. He didn’t believe me. He says he must detain you and is going to inform the palace that you are being held.’

‘Detain? You mean arrest?’ Macro frowned.’Not likely.’