He looked up at Lugos, shaking his head.
‘Wherever they might be.’
Marcus stepped forward.
‘I am Marcus Tribulus Corvus, a representative of Rome, an ambassador if you prefer the term. I have come to Ctesiphon in order to return the King of Kings’ son to him, and to ask the king-’
‘In good time. That you are Roman is evident to all who see you, and your self-professed role is of no interest to the priesthood. And these two men?’
‘I am Martos, King of the Votadini people in the Roman province of Britannia, far to the north of here. And this is Lugos of the Selgovae, my friend and travelling companion.’
The priest looked at Martos for a moment.
‘King? Of how large a kingdom?’
The one-eyed Briton laughed.
‘Small enough, compared to your King of Kings’ empire. But enough to have given the Romans a bloody nose in battle, before my brother in arms here captured me.’
Artapanes shook his head again.
‘A tale the King of Kings will wish to hear, I expect. You will meet him soon enough, and when that time comes I will instruct you as to your behaviour in his presence. For now, you are under strict instructions to stay within the confines of this building, for your own safety. Not all of my people will be as understanding as my master, and many still remember the atrocities inflicted on the city by your legions only twenty years ago. You will be fed and refreshed, and any other needs you have will be looked after by the staff assigned to watch over you. I must leave now, and take information to my senior priest.’
He left the room, and when Martos looked out of the door he found a pair of burly and implacable guards blocking any attempt to follow him.
‘It looks as if we’re here for a while. Perhaps you could use that Greek language of yours and get them to bring us some food?’
Marcus nodded.
‘You realise we’re effectively within the Parthian royal court now? If they’ve decided to have us quietly disappear then poison would be a good way to do so.’
The Briton shrugged.
‘That may be true, but it’s also indisputable that we can’t go without sustenance. Get them to bring some wine as well. If we’re going to die we might as well go to meet our ancestors with some style.’
‘You called for me? I presume it’s important, given the messenger gabbled out the request like a man with his arse on f-’
Still breathing hard from the exertions of climbing up to the northern wall’s parapet, Scaurus followed his first spear’s pointing arm.
‘The enemy are breaking camp.’
The legatus took a long look across the expanse of plain before them. The Parthian infantry were parading in neat formations, while the camp slaves were rapidly striking their tents and packing them onto carts.
‘So they are.’
Petronius grinned at him triumphantly.
‘They’ve had enough! I knew they wouldn’t be able to outlast us! More than one enemy has camped out there to no purpose, and this one’s no different.’
His eyes narrowed at the expression on Scaurus’s face as the legatus looked over the enemy army.
‘Legatus?’
Scaurus looked down at the enemy army again, shaking his head as he realised what it was that was troubling him.
‘They’re not leaving. Look at them. Does that look like an army that’s getting ready to slink away with its tail between its legs? Their flags are unfurled, the infantry are armed and ready to fight.’
‘Why?’
Both men looked round at Julius, who was staring down at the enemy soldiers with a thoughtful expression.
‘Why now? They’ve no more chance of getting over these walls now than they did yesterday, or last week. I’d presume they were just rehearsing for an attack, if they weren’t striking their tents.’
Scaurus leaned over the parapet, looking around the wall’s sweep to the west.
‘But they’re only striking their tents across a quarter-mile front on this side of the city.’
As he spoke, the huge command tent that had been the source of so much amusement collapsed as its central poles were removed, the movement catching Scaurus’s eye as he turned and stared down at the Parthian army in puzzlement. The three men stood and watched as the structure’s white canvas roof sank slowly to the ground, hundreds of slaves converging on the expanses of canvas and dragging it away from the river with no apparent concern for any damage they might do.
‘And that doesn’t make any sense either. Why treat such a valuable piece of equipment with so little care?’
As the previously concealed riverbed was gradually revealed, Scaurus suddenly made the connection that had been nagging at his subconscious since the river had ceased flowing days before, confirming his suspicion that the Parthians had dammed it in the mountains to the north.
‘Gods below! Look at the riverbed!’
With the tent no longer obstructing their view, the reason for the construction of what they had taken for a palatial headquarters became suddenly, sickeningly clear. A ten-foot-deep trench the same width as the river’s bed had been dug from the point where the Mygdonius swung to the east in its bend around the city, the excavation running arrow-straight from the dry watercourse towards the city walls for a hundred paces, the last quarter of its length gradually becoming shallower until the ramp this formed merged with the sandy soil. The soil from its excavation had been dumped into the empty river bed to form a fresh dam at the point where trench and watercourse met, its purpose immediately clear to Scaurus.
‘They didn’t build a dam in the hills to run us out of water, they were building a weapon!’
Petronius stared at him in consternation.
‘They’re going to break the dam?’
‘Yes! And when they do, all the water they’ve got backed up in the hills is going to come down the river with more power than a hundred battering rams! That trench they’ve dug will point the flood straight at this section of the wall, and they’ve dammed the river to make sure the water has nowhere else to go. It will bring tonnes of soil and rock with it, which will shoot down that trench and hit this wall like a monstrous hammer.’
‘But if that much water breaks through the walls …’
Scaurus nodded grimly.
‘There’ll be chaos in the city.’
Julius tilted his head.
‘Listen!’
The distant sound of axes on wood turned Petronius’s face white. Scaurus turned to Julius, pointing at the perfectly straight streets beneath them.
‘If the water breaks this wall down it’ll be channelled through the streets and do the same on the other side. Get the southern wall evacuated!’
The first spear saluted and ran, and the legatus turned to the prefect.
‘I’ll deal with the wall here, you get as many of the streets between here and the southern wall as you can evacuated to the east and west! Go!’
Petronius dithered for an instant, then turned and ran for the nearest tower.
‘Centurion!’
The officer of the guard stepped forward and saluted smartly.
‘Have this section of the wall cleared immediately. We take anything that we can carry and we leave everything that’s too heavy to move. I want every man four towers away from this point and I want it doing now! Move!’
Clearly fighting the urge to question the command, the centurion turned away and started barking orders, sending men running to spread the order in both directions. Scaurus turned back to the scene below, nodding in reluctant admiration as the enemy troops on either side of the river started marching away.
‘Perfect timing …’
In the hills behind the Parthians the sound of axes had died away, and an unnatural silence descended on the field as the enemy soldiers halted their march, leaving a quarter-mile gap in their line with the river at its heart.