Fire in the East

XII

'"Beware the ides of March."' The telones shook his head sadly as he watched the cavalcade pass. "Calpurnia turned in her sleep and muttered… beware the ides of March."'

After the last horseman had jingled out from under the tall arch of the western gate, there was an unnatural silence, as if everything were holding its breath.

'What the fuck are you on about?' The boukolos often sounded put out when confronted by things outside his limited experience.

'That is poetry that is. That old centurion, the one who was always drunk, always quoting that he was… you know the one, the Sassanids got him somewhere downriver, cut his balls off, and his cock- shoved them down his throat.' The telones shook his head again. 'Poor bastard. Anyway, today is the ides of March. The day Julius Caesar was murdered by some of his friends. Not a good day to start out on something, not what you would call a day of good omen.'

Just beyond the Palmyrene Gate Ballista had halted his small mounted force to reorder for the march. Two equites singulares were put on point duty in front, and one at each side and the rear. The northerner did not intend to be surprised if he could help it. Ballista would lead the main body with Maximus, Romulus and Demetrius. The two scribes and two messengers would ride next, then the five servants leading the five packhorses. The other five equites singulares would form the end of the column. Ordered like a miniature army, scouts out and baggage in the middle, the force was as ready as it could be for any trouble-not that trouble was expected.

This was a straightforward tour of inspection. The small fort of Castellum Arabum, garrison to twenty camel-riding dromedarii from Cohors XX, lay to the south-east, some thirty miles as the crow flies, some forty-five by road. Castellum Arabum was now the furthest south of Rome's possessions on the Euphrates. It was the tripwire that was intended to warn of the coming of the Sassanids. No enemy had yet been seen. Local experts assured Ballista that it took time for the Sassanids to assemble their forces in the spring; they would not come until April, when there was grass for their horses and no danger of rain ruining their bowstrings. No hostile encounters were expected on this trip: two days' easy ride down, a day to look at the defences and make a speech to hearten the dromedarii, and two easy days' ride back.

As the men on point duty rode off to take up their positions, Ballista looked back at Arete. Bricklayers still plied their methodical trade, facing the earth, rubble and layers of reeds that formed its core but the great glacis that fronted the western wall was in essence complete. The 500 paces that separated Ballista from it was now a wasteland. Scattered low piles of broken bricks and smashed stones were all that remained of the once proud tower tombs of the necropolis.

Looking at the wasteland he had created, Ballista wondered what he should feel. A good Roman would probably be meditating on something like the immutability of fate. To his surprise, Ballista's main feeling, rather than pity or guilt, was one of pride: I, Ballista son of Isangrim, did this – look on my works and tremble. He smiled to himself. Everyone knows we barbarians enjoy destruction for its own sake. And maybe not just us. He half-remembered a line from the AgricoLa of Tacitus: 'Rome creates a desert and calls it peace.' Tacitus had put the words into the mouth of a Caledonian chief called Calgacus. Isangrim's sense of humour had not deserted him all those years ago when naming the Caledonian slave who would look after his son.

The point men were in position. Ballista signalled the advance. The small column set off at a walk towards the south. The cool of the night was giving way before the early morning sun. Only down in the ravines and on the surface of the river was the mist still clinging. Soon it would be hot – or hot by northern standards.

The road was unpaved but, created by millennia of caravans, it was mainly broad and easy to follow. For the most part it kept on the plateau away from the river. Sometimes it even diverted quite some distance inland to go round the ravines that ran down to the Euphrates; at others it descended into these wadis, sometimes climbing straight out the other side, sometimes following the floodplain until the gradient allowed it to climb back to the plateau.

Down by the river they stopped for lunch in the shade of a grove of wild date palms. It was peaceful in the dappled sunlight, listening to the river slip by. Ballista had ordered that the scouts remain on the look-out above them on the plateau. After he had eaten the cold pheasant, bread and cheese that Calgacus had packed for him, he lay back and closed his eyes.

It was good to be out in the country, slightly stiff and tired after a morning in the saddle. It was good to be away from the endless interruptions and irritations of organizing the defence of Arete. Sunlight coming through the palm fronds made shifting patterns on his eyelids. The south wind was getting up; he could hear it moving through the stands of tamarisk. But even in this almost idyllic setting his mind would not rest. Castellum Arabum had a garrison of twenty. It was too few to mount a defence, and more than was needed for a look-out post. He had inherited this arrangement from the previous Dux Ripae. So far he had not found time to visit Castellum Arabum. Now, maybe it was too late to start altering things.

Ballista sat up and looked around at his men. They should start moving. Again it struck him how easy it was to slip into other people's ways of doing things. Twenty-three men and twenty-eight horses just to transport him to look at a small fort less than fifty miles away. Like the garrison of Castellum Arabum, the column was the wrong size. It was too small to fight off any determined Sassanid war party and too large to move quickly. The size of Ballista's entourage, somehow without any intention on his side, had expanded to fit Roman expectations. A Dux on the move needed scribes, messengers, guards. It was lucky he had not found himself saddled with a masseur, pastry cook and a hairy Greek philosopher as well. Ballista felt he should have ridden down to Castellum Arabum with just Maximus and Demetrius. Moving fast, they could have kept away from any trouble. It would be a foolish tent-dweller who decided to try to rob Maximus.

The tethered horses had eaten their hay and were either sleeping or desultorily searching the ground for anything edible. The sun was hot but in the shade of the stand of trees it was still cool. The men were resting or lying down talking quietly; there was all the time in the world. Ballista lay back down and shut his eyes. A sudden childish fantasy came over him. Why not just saddle Pale Horse, slip away and all alone ride west, never to return to the bustling irritations of Arete? But straight away he knew it was impossible. What about Maximus and Demetrius – and Calgacus? And then the big question: where would he go? To sit in his sun-drenched garden on the cliffs of Tauromenium or to drink by the fire in the high-roofed hall of his father?

At length it was Romulus who started them moving again, pointing out somewhat reproachfully that now they would not reach the ruined caravanserai that marked the half-way point by nightfall. Ballista said it did not matter. Maximus loudly and repeatedly said that it was a blessing in disguise: such places were undoubtedly crawling with snakes; the open air was far, far safer.

The afternoon followed the pattern of the morning, the river to the left, the wide emptiness of the sky and the land, the broad road along the plateau always unrolling to the south. As in the morning, sometimes they followed the road down into ravines, the horses' hooves sending showers of stones ahead, sometimes the road climbed straight out again, and sometimes it took its time, meandering down to the river and running along the floodplain, through the tamarisks and date palms, until a suitable opportunity appeared to regain the plateau.

The low winter sun was throwing long shadows to their left, making strange elongated beasts of horses and riders, when something happened. It started quietly. Maximus leant over, touched Ballista's knee and jerked his head back in the direction they had come. Ballista pulled his mount round to one side to see better. The cavalryman on rear point duty was in sight. He was a long way off but rapidly catching them. He was galloping, although not flat out. The south wind was making the dust his horse kicked up stream out behind them. The column came to a halt. Realizing he was observed, the cavalryman gathered the ends of his cloak in his right hand and waved them in the air, the usual signal for Enemy in Sight.

He was still some way off. They waited, all eyes not on the cavalryman but looking beyond him to see what might appear. The five equites singulares with the column fanned out into a line. Behind them the servants waited phlegmatically with the pack animals. The scribes and messengers talked rapidly among themselves. They all looked very frightened, except the scribe with the Spanish accent, who waited as impassively as any of the soldiers.

Nothing had shown itself by the time the cavalryman brought his horse to a halt before Ballista.

'Dominus, Sassanid light cavalry, bowmen – about fifty or sixty of them – about three miles away.'

'Which direction are they heading?'

'They were coming from the west, down from the hills to the river.'

'Did they see you?'

'Yes.'

'Did they chase you?'

'Not straight away. They waited until their lead group had reached the river, then they started to follow me, but at a walk.'

'Lead group?'

'Yes, Dominus. They were split into five groups stretched out over the three or four miles between the hills and the river.'

'Had they seen the rest of us?'

'I don't think so, Dominus.'

Allfather, but this looks bad, thought Ballista. Everyone was looking at him, waiting. He tried to block them out and think clearly. He looked around. Still nothing to be seen.

The man on point to the left, the east, was only a couple of hundred paces away; beyond him was the cliff down to the river. To the west the scout was about 400 paces out. Straight ahead to the south neither of the scouts could be seen, but the fresh wind was carrying a wide line of dust towards them from some miles away.

'Romulus, where exactly are we?' Ballista worked hard at making his voice sound calm, possibly even slightly bored.

'Just under twenty miles out of Arete, Dominus, just over twenty-five short of Castellum Arabum. The disused caravanserai is about three miles ahead.'

'Is there any shelter up in the hills to the west – a fort or settlement, occupied or not?'

'Only the village of Merrha to the north-west. It is occupied and walled, but the Sassanids are between us and it.' Romulus brightened. 'But we can go to the disused caravanserai. Its walls still stand, and we can reach it long before the Persians catch up with us.'

'Yes, it is tempting. But I think that it is possibly the last thing we should do.' Ballista circled his arms, calling in the men from left and right. 'Romulus, which of the equites singulares here has the best mount?'

Before the standard-bearer could answer, another cheekily cut in. 'No question about that, Dominus, me.' The man grinned. Demetrius whispered in Ballista's ear: 'Antigonus.'

'Right, Antigonus, I want you to go and bring in the two scouts from out in front. Meet us back at the last grove of date palms we passed through, down by the river. We will wait for you there. If we are not there, the three of you are to make your own way either to Arete or Castellum Arabum. Save yourselves as best you can. There is not a moment to lose. I will explain when you return. Take care.'

While Antigonus set off to the south at a gallop, the column retraced its steps to the north, also at a gallop. Once they were in the stand of trees, Ballista rattled out orders to put them in a new formation, his voice little above a fierce whisper. They were to form a wedge, an arrowhead. Ballista was to be the point, Maximus close to his right and half a length behind him, three equites singulares beyond and behind him. Romulus and the other four equites singulares were to comprise the left side of the formation. Demetrius and the Spanish scribe were to ride right behind Ballista, then the rest of the staff and the servants with the packhorses.

Ballista quietly, and he hoped calmly, explained what he was about. The aim could not be simpler: they were to break through the group of Sassanids closest to the river. With luck, the Persians would be taken by surprise as they charged out of the shelter of the date palms. Again with luck, this group of Persians down by the river would at that moment be out of sight of the others up on the plateau, buying the Romans just a little time. Anyway, once through the nearest group, the Romans would ride flat out for Arete and safety. With yet more luck, the night would hide them from the pursuing enemy.

It was growing dark among the date palms. The shadow of the cliff stretched out across the Euphrates. The temperature was dropping quickly. The wind worried at the palm fronds and tamarisks. The waters sucked at the banks. It was hard to hear anything clearly and difficult to see in the gathering gloom. Somewhere on the other side of the river a jackal barked.

'How do you know we are in a trap?' Maximus whispered, his mouth very close to Ballista's ear. The northerner took his time replying, wondering how to put his suspicions into words.

'The Sassanids between us and Arete are not acting like a normal scouting party looking for information. If that is what they were they would have chased the one of us they saw, chased him flat out – catch him and they could go home, out of danger. Instead they are moving south at a slow walk, strung out across the plain between the river and the hills. They have been sent on a flank march to catch any of us who escape from the main ambush. That line of dust in the sky to the south – it might just be the wind, but to me it looks all too like the sort of dust raised by a lot of cavalry moving fast.'

The sound of a scatter of stones and the first of the Persian horsemen appeared. They rode out of the wadi and on to the floodplain, advancing in the gathering gloom. As the scout had said, they were light cavalry, horse archers. Dressed in tunic and trousers, they were unarmoured. One or two had metal helmets, but the majority were bareheaded or wore just a cloth cap or bandana. Each had a long cavalry sword on his left hip, some had a small round shield on their left arm. There seemed to be at least fifteen of them. If they had ridden in any particular order, it had been dissipated by the descent into the ravine. Now they rode in a loose group, three horses across and four or five deep. They came on at a walk, their horses stepping delicately.

The Sassanids were getting close. Even in the gloom Ballista could make out their long hair, the glitter of their dark eyes. They were getting too close. Any moment now one of them would see the immobile forms waiting in the deeper shadow of the palm grove. Ballista could feel his heart beating as he sucked in air to fill his lungs.

'Now! Charge! Charge!' he yelled, kicking his heels into Pale Horse's flanks. There was a second's pause as the gelding gathered his quarters and then they were crashing through the reeds which fringed the grove and hurtling towards the Persians. There were exclamations of surprise, shouts of warning. The enemy tugged swords from scabbards. Their horses had come to a halt, some wheeling pointlessly. Ballista aimed at a point between two of the leading Sassanids. As he shot between them the northerner directed a vicious cut at the head of the Persian on his right. The man blocked the blow. The shock jarred Ballista's arm.

There was virtually no gap between the next two Sassanids in front of the northerner. He jabbed his heels into Pale Horse and set him at them. The gelding's left shoulder crashed into the withers of the Persian horse to the left. It staggered back. A gap opened, but the impact had robbed Pale Horse of all momentum. Ballista kicked furiously. His mount responded, leaping forward. To his right he saw Maximus's blade topple first one then another Persian out of the saddle.

They were nearly through; just one line of Persians still ahead. Maximus was no longer right on his shoulder. Ballista drew his spatha back over his left shoulder and aimed a mighty downward cut at the Sassanid to his right. Somehow the man blocked it with his shield. Ballista wrenched his blade free of the splintered wood and cut horizontally over Pale Horse's ears at the man on his left. This time he felt the blade bite home. There were no more enemy in front.

The force of the blow smashed Ballista's head forward. His nose crunched into Pale Horse's neck and blood poured from it. It was broken. He could feel more blood running down the back of his neck. Instinctively he twisted round to the right, bringing his spatha up in an attempt to parry the next blow he knew would come, the blow meant to finish him.

There was the Sassanid, sword arm raised. The bastard smiled – and looked down, clutching his side, staring stupidly at the sword wound.

Ballista waved his thanks to the Spaniard and kicked on. The scribe grinned back and flourished his sword – then the look on his face changed to shock. His horse disappeared from beneath him. He seemed to hang for a moment, then he went down into the tumbling, sliding mass of his own horse and under the hooves of the following Roman and Sassanid mounts alike.

There would be time for pity or guilt later. Ballista could not have stopped Pale Horse in any case. They rushed on, up the wadi, up its steep bank. As they emerged on to the plateau it grew much lighter. Up here the sun had not quite set. Without looking to see who was still with him, Ballista set the pace at a hell-for-leather gallop. He angled away from the road towards the north-west. It was vital that they pass inland of the next ravine.

The northerner looked over his left shoulder. There was the next group of Persians, about twenty of them. They had turned and were now riding hard to cut Ballista and his men off. Their long shadows flickered over the plain. The other groups of Persians had also turned, but they could not possibly reach the ravine in time; for now they were of no concern.

Ballista heard Maximus shout something. He ignored him; he needed to think. Despite the growing ache in his head, his mind was clear. He was calculating the distances and the angles. He saw it all as if watching from a great height: the fixed point of the head of the ravine, the two moving bodies of horsemen converging on it. He leant forward in the saddle, pushing Pale Horse for just that last bit of effort, that last pace or two of extra speed.

Ballista and his men made it with a little bit to spare. They skidded round the mouth of the ravine with the Persians still fifty paces away. They pushed on, but some of the urgency seemed to have gone out of the pursuit. Soon they were a couple of hundred paces ahead. Ballista slackened the pace. It was now twilight. There was something that had to be done. He did not want to do it, but it could not be deferred. He looked round to see who had fallen.

Maximus was there. Demetrius was there. Romulus was there, and four equites singulares, one scribe, both messengers and three servants, the latter commendably still leading their packhorses. The butcher's bill could have been higher – three soldiers, one Spanish scribe and two servants. It could yet mount higher, much higher.

The moon was up, but the strong south wind was pushing tattered clouds across its face.

'Are you all right? You look terrible,' Maximus called.

'Never better.' Ballista replied sourly. 'Like a slave at Saturnalia.'

'Do you think they will give up?' Demetrius asked, trying but failing to keep the desperate wishful thinking out of his voice.

'No.' It was Maximus who firmly crushed his hopes. 'They are settling in for the long haul. They intend to run us down during the night.'

As the Hibernian spoke, a series of twinkling lights appeared strung out between the river and the hills.

'Do we still have a lantern?' Having been assured by one of the servants that they still had two, Ballista ordered one of them to be lit. The order was obeyed amid unvoiced horror. Bright golden light spilled out around them.

'I do not want to appear stupid, but does not your lamp make it just a bit easier for your Persians to follow us?' Maximus asked.

'Oh yes, and that is just what I want.' Ballista asked a servant to tie the lantern securely to the saddle of one of the packhorses. They rode on in silence for a time, travelling no faster than an easy canter. The clouds were building up, the moon ever more obscured. Now it was pitch dark outside the pool of lantern light.

'Romulus, you know where the village of Merrha lies?'

'Yes, Dominus. Off in the hills to the north-west, not far now, four miles maybe.'

'I want you to lead the packhorse with the lantern in that direction. When you think that you have gone far enough or the Sassanids are getting too close, set the packhorse running free and ride for Arete.'

The standard-bearer smiled enigmatically. 'We will do what is ordered, and at every command we will be ready.' He spoke ruefully. He took the horse's leading rein and set off diagonally across the dark plain.

'Now we ride flat out again.'

In complete silence the small group rode hard. Off to their left, the light of Romulus's lantern bobbed across the plain towards the just distinguishable darker mass of the hills. Beaded across the wide plain were the lights of the Sassanids. Soon they altered course and surged after the lone Roman lantern. Ballista and his remaining twelve men rode north into the darkness to safety.

Not one was looking back when the line of Sassanid lights converged on the solitary lantern making vainly for the hills.

They were found by the patrol just after dawn; Turpio was working Cohors XX hard these days: the first patrols set out early, always in the dark. When Ballista and his party were found they were still a couple of miles from town, and in a bad way. Horses and men were completely exhausted. The flanks of the horses were covered in a white foam of sweat, their nostrils wide, mouths hanging open. The men were ashen-faced, almost insensible with fatigue. Apart from a servant more dead than alive who was slung over a packhorse, they were walking, stumbling along by their mounts. The Dux Ripae looked terrible, his face masked in dried blood, staggering, hanging on to the near-side pommel of his horse's saddle.

Before they reached Arete the Dux called a halt. He washed as much as he could of the blood from his face. He put on a hooded cloak borrowed from one of the troopers. He climbed back on to his horse and pulled the cloak up to hide his injuries. He rode into town with a straight back.

After the battered cavalcade had passed through the Palmyrene Gate the telones looked at the boukolos with an air of smug vindication.

'Calpurnia mutters… There is truth in poetry, boy – looks like that old centurion knew a thing or two: the ides of March did not do our barbarian Dux any good.'

'And knowing poetry didn't do your fucking centurion much good either; he still had his bollocks cut off,' replied the boukolos. 'Now this is what I call an omen: first time our commander meets the Persians they nearly kill him. Bloody bad omen that.'

From this first conversation discussions of the events at Castellum Arabum spread out across the town of Arete.

An hour or so after their return, Ballista, Maximus and Demetrius were lying in the tepidarium of the private baths attached to the palace of the DuxRipae. The doctor had come and gone. He had put a couple of stitches in a gash on Maximus's thigh and five or six in the scalp wound on the back of Ballista's head. Demetrius had come through untouched.

They were lying in silence, dog-tired, aching. Ballista's head throbbed.

'No one to blame but yourself… your own fucking fault,' Calgacus grumbled as he brought in some food and drink. Ballista noted that now the Caledonian felt firee to express his opinions before Maximus and Demetrius.

'Those notices you keep posting up in the agora: "the Dux Ripae will be virtually on his own riding down to some fly-blown piece of shite in the middle of nowhere; why not send a message to the Sassanids so they can ambush him?" Never listen… just like your bloody father.'

'You are right,' Ballista said tiredly. 'There will not be any more notices, no more advance warning of what we are going to do.'

'Surely it could just be chance, bad luck? Their patrol just happened to be there and we just happened to run into them. Surely there does not have to be a traitor?' Demetrius's tone could not be mistaken. He desperately wanted one of them to say he was right, it was unlikely to happen again.

'No, I am afraid not,' said Ballista. 'They knew we were coming. That dust cloud in the south was the main force. It was intended to take us as we camped at the disused caravanserai. We were behind schedule. We were never meant to see the ones we ran into. They were just a screen to catch any of us who managed to escape the massacre.'

'So,' said Maximus, 'you see the virtue in sloth – a good long meridiatio saved our lives.'

Four hours after the Dux Ripae rode through the Palmyrene Gate the frumentarii were in their favourite bar in the south-east of the city.

'Left him to die like a dog in the shand.' The emotion was not counterfeit; the North African was packed full of anger.

'Yes,' said the one from the Subura. He kept his voice neutral. He was sorry for the Spaniard, Sertorius as he had dubbed him, but what else could the Dux Ripae have done – stop and get the whole party killed?

'Like a dog… hope the poor bashtard was dead before they got to him.'

'Yes,' repeated the one from the Subura. The North African's Punic accent was becoming stronger, the volume louder and, although the bar was almost empty, the Roman did not want attention drawn to them.

'I will fix that bashtard barbarian… write a report that will fix him, write such a report on him, the bashtard. I just wish I could be there when the princeps peregrinorum hands the report to the emperor – see the look on Valerian's face when he hears how his barbarian boy has fucked up – the fucking bashtard.'

'Are you sure that is a good idea?'

'Godsh below it is… fix that bashtard good and proper.'

The Persian rug which curtained off the inner room was drawn back. Mamurra walked through and over to the table of the frumentarii. He leant down, bringing his great slab of a face close to them.

'My condolences on the loss of your colleague.' He spoke softly, and walked on without waiting for a reply. The two frumentarii looked at each other in some consternation. How long had the praefectus fabrum been there? What had he heard? And was there something in the way he had pronounced 'colleague' that implied more than the Spaniard being a fellow member of the staff of the Dux Ripae?

Seven days after the events at Castellum Arabum Antigonus rode in on a donkey led by a peasant. He told the telones and boukolos to fuck off, made himself known to the centurion from Legio [III in charge at the Palmyrene Gate and, within half an hour, he was in the palace. Sitting in the private apartments of the Dux Ripae, food and drink to hand, he told his story.

Yes, Antigonus had found the two troopers on point duty. The Sassanids had been questioning them, the poor bastards, as he rode past. Oddly, no one had pursued him. There was a line of Persian cavalry coming up from the south, a lot of them. Antigonus had turned his horse loose – excellent horse it was too – hidden most of his kit in a ravine and swum out to an island in the Euphrates. He told them proudly that he was a Batavian from the Rhine. The whole world knew that the Batavians were great swimmers. As everyone in the party of the Dux had taken the standard three days' rations with them, he had sat on his island for two days. He had not seen a Persian after the first day. Then he had swum ashore, picked up as much of his kit as he could carry and walked south to Castellum Arabum. It had not been pretty. Eighteen heads were mounted over the gate and on the walls. The other two dromedarii might have escaped but, more likely, they had been taken for further questioning.

'Anyway,' Antigonus continued, 'I found a peasant who, out of the kindness of his heart, offered to let me have his donkey and bring me home to Arete.' In response to a sharp look from Ballista he hurried on. 'No, no, he is fine. In fact, he is waiting in the first courtyard for the huge reward I said the Dux Ripae would pay him.' Ballista nodded to Demetrius, who nodded back to say he would deal with it.

'There is more. On my way back I came across Romulus, or what was left of him. Nasty – he had been mutilated, hopefully after he was dead.'

The ever-changing stories spread out far beyond the city of Arete. Ten days after the reality had played out in darkness and fear by the Euphrates, a messenger prostrated himself in the magnificent throne room in the Persian capital of Cetisiphon and told a version of the story to Shapur, the Sassanid King of Kings. Twenty-six days after that, a messenger prostrated himself in the palace high on the Palatine Hill and told the first of several versions of the story that Valerian Imperator of the Romans would hear. Another three days elapsed before a messenger tracked down Gallienus, Valerian's son and fellow Augustus, by the cold banks of the Danube. By then, many more things had happened at the city of Arete and, for most there, the events at Castellum Arabum were a fading memory.

From the walls of Arete, for a long time the only sign of the approach of the Sassanid horde was the thick black cloud looming up from the south. On the morning of the fourteenth of April, the day after the ides of the month – always an unlucky day – Ballista, accompanied by his senior officers, staff and familia, took his stand on the battlements above the Palmyrene Gate. There was the cloud downriver, coming up from the realms of Shapur. Dark and thick, it was still some way off, at least as far as the disused caravanserai, if not as far as Castellum Arabum. No one needed to ask what caused it. It was impossible to escape the thought of the tens of thousands of marching men, horses and other, terrifying beasts kicking up the dust, of the smoke writhing up oily from the innumerable fires consuming everything in the path of the horde from the east.

At twilight a line of campfires could be seen burning no more than a couple of miles from the city. The Sassanid scouts were settling in for the night. Later, in the depth of the night, more fires flickered into life, stretching round in an arc along the hills to the west. After midnight a terrible orange glow lit the sky to the north-west as the Persian outriders reached the villages. By cock crow smudges of fire and smoke had appeared on the other side of the river to the east. Everyone within the walls of the town of Arete knew they were surrounded, cut off by land from help or flight. And yet, so far, they had not seen a single one of the warriors of Shapur.

At dawn the Dux Ripae and his men were still at their post. Most had left to try and rest for an hour or two but, to Ballista, sleep seemed impossible on a night so obviously momentous. Wrapped in a sheepskin, he leant against one of the two pieces of artillery on the roof of the gatehouse, a huge twenty-pounder ballista. His eyes ached with fatigue as he peered out on to the western plain. He thought he saw movement but, unsure his tired eyes weren't playing tricks on him in the grey light, he waited until one of the others shouted and pointed. There they were. About where the necropolis used to end, dark shapes were moving fast through the early morning mist. The small amorphous groups of mounted scouts, dividing, reuniting, crossing each other's tracks, reminded Ballista of animals running before a forest fire, until the inappositeness of the image struck him. These animals were not fleeing anything, they were hunting, hunting for a means to attack the northerner himself and all those it was his duty to protect. They were wolves looking for a way into the sheepfold.

The sun was well clear of the horizon and it was towards the end of the third hour of daylight when the vanguard of the Sassanid army finally came into view. Ballista could make out two long dark columns which seemed, like enormous snakes, to crawl towards him infinitesimally slowly across the face of the land. Above each hung a dense isolated cloud of dust. The base of a third cloud had not yet come into sight. The northerner could make out that the nearer column was composed of cavalry, the further of infantry. He thought back to his training in fieldcraft: this meant that the columns must be within about 1,300 paces. But, as he could not yet make out any individuals, they must still be more than 1,000 paces away. If he had not known of their advance toward him, the rays of sunlight flashing perpendicular off spear points and burnished armour would have told him.

Time passed slowly as the columns continued to crawl towards the city. When they were about 700 paces away (the distance at which a man's head can be made out as a round ball) they began to incline away to the north. Ballista moved to the parapet and called Bagoas to his side. By the time the columns reached the beginning of the wasteland where the furthest tower tombs had once stood, they were moving parallel to the western wall. The third column was now revealed as the baggage and siege train. The nearest column, the cavalry, was close enough for Ballista to be able to see the lighter-coloured spots of the men's faces, their costumes and weapons, the bright trappings of their mounts, the banners above their heads: about 500 paces away, just out of artillery range.

Speaking in Greek, Ballista asked Bagoas if he could identify the units of the Sassanid horde and their leaders.

'Excellent, how very cultured our siege will be. We can begin with our very own View from the Wall.' Although Acilius Glabrio had interrupted in Latin, he used the Greek word teichoskopia' for the View from the Wall. To any educated person in the imperium, the word instantly summoned up the famous scene in the Hiad of Homer where Helen looked down from the walls of Troy and identified each of the bronze-armoured Achaeans come to tear her from her lover Paris and take her home to her rightful husband, the broad-shouldered Menelaus. 'And who better than this delightful Persian boy to play the Queen of Sparta?' Acilius Glabrio smiled at Ballista. 'I do hope our Helen does not feel the need to criticize the manliness of her Paris.'

Bagoas's grasp of Latin might still be rudimentary, and Ballista had no idea if the boy knew anything of the Iliad, but it was obvious that he realized he was being mocked, that his masculinity was being questioned. The boy's eyes were furious. Before he could do anything, Mamurra spoke to Acilius Glabrio.

'That is enough, Tribune. This is not a time for dissension. We all know what happened to Troy. May the gods grant that these words of ill omen fall only on the man who utters them.'

The young nobleman spun around looking dangerous. He brought his well-groomed face inches from that of the praefectus fabrum. Then he mastered himself. Clearly it was beneath one of the Acilii Glabriones to bandy words with sordid plebeians like Mamurra. 'The men of my family have always had broad shoulders.' With patrician disdain, he brushed an imaginary piece of dirt from his immaculate sleeve.

Ballista pointed to the enemy and indicated to Bagoas to start talking.

'First ride some of the non-Aryan people subject to my lord Shapur. See the fur cloaks and long hanging sleeves of the Georgians, then the half-naked Arabs, the turbaned Indians and the wild nomadic Sakas. From all the corners of the world, when the King of Kings calls, they obey.' The boy shone with pride. 'And there… there are the noble Aryan warriors, the warriors of Mazda, the armoured knights, the clibanarii.'

All the men on the gate tower fell silent as they regarded the serried ranks of the Sassanid heavy cavalry, the elite of Shapur's army. Five deep, the column seemed to stretch for miles across the plain. As far as could be seen were armoured men on armoured horses. Some looked like living statues, horse and man clad in iron scales, iron masks covering any humanity. The mounts of others were armoured in red leather or green-blue horn. Many wore gaudy surcoats and caparisoned their horses similarly – green, yellow, scarlet and blue. Often man and beast wore abstract heraldic symbols – crescents, circles and bars – which proclaimed their clan. Above their heads their banners writhed and snapped – wolves, serpents, fierce beasts or abstract designs invoking Mazda.

'Can you tell who leads each contingent from their banners?' Ballista had had this moment in mind when he purchased the Persian youth.

'Of course,' Bagoas replied. 'In the van of the clibanarii ride the lords from the houses of Suren and Karen.'

'I thought that those were great noble houses under the previous regime. I assumed they would have fallen with the Parthian dynasty.'

'They came to see the holiness of Mazda.' Bagoas beamed. 'The King of Kings Shapur in his infinite kindness restored their lands and titles to them. The path of righteousness is open to all.'

'And the horsemen behind them?'

'Are the truly blessed. They are the children of the house of Sasan – Prince Valash the joy of Shapur, Prince Sasan the hunter, Dinak Queen of Mesene, Ardashir King of Adiabene.' Pride radiated from the boy. 'And look… there, next in the array, the guards. First the Immortals, at their head Peroz of the Long Sword. Then the Jan-avasper, those who sacrifice themselves. And see… see who leads them – none other than Mariades, the rightful emperor of Rome.' The boy laughed, careless of the effect his words were having, the punishments they might bring. 'The path of righteousness is open to all, even to Romans.'

Out of the swirling dust kicked up by many thousand horses, enormous grey shapes loomed. One, two, three… Ballista counted ten of them. Bagoas literally jumped for joy, clapping his hands. 'The earth-shaking elephants of Shapur. Who could think to stand against such beasts?'

Ballista had seen elephants fight in the arena but had never himself faced them in battle. Certainly they looked terrifying, not altogether of this world. They had to be at least ten foot high at the shoulder, and the turrets on their backs added yet more height. Each turret was packed with armed fighting men. At the bidding of an Indian who sat astride behind their ears, the elephants moved their great heads from side to side. Their huge tusks, sheathed in metal, dipped and swung from side to side.

'Frightening, but inefficient.' The experience in Turpio's voice was reassuring. 'Hamstring them, or madden them with missiles. Kill their drivers, their mahouts, and they will run amok. They are as likely to trample their own side as us.'

The Sassanid army had halted and turned to face the city. A trumpet rang out, clear across the plain.

From the left a small group of five unarmed horsemen appeared, moving at an easy canter. In their midst an enormous rectangular banner embroidered in yellow, red and violet and embedded with jewels that flashed as they caught the sunlight hung from a tall crossbar. The banner was topped by a golden ball, and bright strips of material streamed out behind it.

'The Drafsh-i-Kavyan, the royal battle flag of the house of Sasan.' Bagoas almost whispered. 'It was made before the dawn of time. Carried by five of the holiest of mobads, priests, it goes before the King of Kings into battle.'

A lone horseman appeared from the left. He rode a magnificent white horse. His clothes were purple and on his head was a golden domed crown. White and purple streamers floated out behind him.

'Shapur, the Mazda-worshipping divine King of Kings of Aryans and Non-Aryans, of the race of the gods.' Bagoas prostrated himself on the battlements.

When Shapur reached the Drafsh-i-Kavyan standard at its station in front of the centre of his army, he reined his horse to a halt. He dismounted, seemingly using a kneeling man as a step. A golden throne was produced and Shapur sat on it. A large number of other men ran about.

'Enemy numbers?' Ballista threw the question open to his consilium gathered on the roof of the gate tower.

'I estimate about 20,000 infantry,' Acilius Glabrio answered promptly. 'Then about 10,000 heavy cavalry, 8,000 of them Sassanid clibanarii and 1,000 or so each from the Georgians and Sakas. There seem to be roughly 6,000 barbarian light cavalry at the front of the column, maybe 2,000 each from the Arabs and Indians and 1,000 each from the Georgians and Sakas.' Whatever one thought of the young patrician, it could not be denied that he was an extremely competent army officer. The estimates mapped almost exactly on to those Ballista had made.

'The Sassanids' own light cavalry?' The northerner kept the question short, business-like.

'Impossible to say,' answered Mamurra. 'They are scattered all over the countryside burning and plundering. There is no way for us to estimate their strength. However many there are, the majority will be on our side of the river. There will be just a few across the river – the nearest ford is about 100 miles downstream and we have commandeered every boat for miles. They will not have committed many men across the river.'

'What the praefectus fabrum says is true,' said Turpio. 'We cannot know their numbers. At Barbalissos there were somewhere between five and ten light cavalrymen to every clibariarius, but at other times their numbers have been said to be about equal.'

'Thank you,' said Ballista. 'So it seems the enemy have somewhere between 40,000 and 130,000 men to our 4,000. At best we are outnumbered ten to one.' He smiled broadly. 'It is very lucky for us that it is a bunch of effeminate easterners who get scared at the sound of a noisy dinner party let alone a battle. We would not want to fight anyone with any bollocks at these odds.' The army officers all laughed. Demetrius tried to join in.

Ballista noted that the baggage train had caught up with the other columns, and that its first task was to erect a spacious purple tent just behind the centre of the army. The tent, which could be none other than Shapur's, was being set up directly along the western road out of Arete, about 600 paces from the Palmyrene Gate.

Men continued to rush around Shapur.

'What is going on?' Ballista asked Bagoas, who was still prostrate.

'The King of Kings will make sacrifice of a kid to ensure that Mazda smiles on his works here, to ensure that this town of unbelievers falls to the army of the righteous.'

'Get up off your belly, and mind what you say. You might push our patience too far,' snapped Ballista.

Despite his tone, the northerner was actually pleased with his Persian slave. Just as he had hoped, he was learning a lot about his enemy from the boy. There was the voluble religious fervour, linked to the awe of the king, and the fact that Bagoas had not considered the Sassanid infantry even worth mentioning. So, an army of fanatics of whom only the cavalry were any good at fighting. Ballista just had to hope that this individual Persian was not totally unrepresentative of his countrymen.

As the boy got up, he briefly put his arms behind his back as if they were bound. Ballista knew that this was the Persian gesture of supplication – possibly the boy was begging Shapur not to blame him for being a slave of the King's enemies.

The sacrifice having been made, Shapur could be seen issuing orders to the nobleman known as the Suren. On being asked to explain, Bagoas said that the King of Kings would now send the Suren to Ballista. If Ballista and his men submitted and converted to the most righteous path of Mazda, their lives would be spared.

As he watched the Suren walk his horse along the road towards him, Ballista's thoughts were racing. While the horseman was still about 200 paces away, Ballista quickly issued orders to two of his messengers. All the ballistae on the western wall were to prepare to shoot at the enemy army. They were to take maximum elevation as if going for their greatest range but their crews were to loosen the torsion springs by two turns of the washers so that their missiles fell well short of their maximum range. Hopefully it would deceive the enemy about the true range of the ballistae. The messengers ran off along the wall walk; one south, the other, the one with the heavy accent from the Subura, north. With the Suren about a hundred paces away, Ballista told Mamurra to go below to the first floor of the tower and train one of the bolt-throwers on the approaching messenger. On Ballista's command, a bolt was to be shot just over the head of the Suren.

He was riding a beautiful Nisean stallion. It was jet-black, deepchested, no less than sixteen hands tall. Good job it was light cavalry that ambushed us, Ballista thought. Pale Horse would never knock a beast like that back on its hocks.

The Suren reined in his horse. He had stopped about thirty paces from the gate. Ballista was relieved. The enemy nobleman would have detected two of the traps that Ballista had set. He had crossed over two pits in the road, one at a hundred and one at fifty paces from the gate. The pits were concealed from view, boarded over with sand thickly spread on top, but the hollow ring of his stallion's hooves would have warned the Persian. Yet so far he should know nothing of the final pit, the crucial one, just twenty paces from the gate.

The Suren took his time taking off a tall helmet in the shape of a predatory bird, possibly an eagle. His own features, once revealed, did not look greatly different. With the assurance of a man whose ancestors have owned broad pastures for generations without number, he looked up at the men on the battlements.

'Who is in command here?' The Suren spoke in almost unaccented Greek. His voice carried well.

'I am Marcus Clodius Ballista, son of Isangrim, Dux Ripae. I command here.'

The Suren tipped his head slightly to one side, as if better to study this blond barbarian with a Roman name and title. 'The King of Kings Shapur bids me tell you to heat the water and prepare his food. He would bathe and eat in his town of Arete tonight.'

Ballista tipped his head back and laughed.

'I am sure that the bum-boy who passes for your kyrios would love to get in the bath and offer his arse to anyone interested, but I fear that the water would be too hot and my soldiers much too rough for his delicate constitution.'

Seemingly unmoved by the obscenity, the Suren methodically began to undo the top of the quiver that hung by his right thigh.

'What the hell is he doing?' Ballista demanded of Bagoas in a whisper.

'He is preparing formally to declare war. He will shoot the cane reed that symbolizes war.'

'Like fuck he will. Quietly pass the word for Mamurra to shoot.'

The order was muttered from man to man across the gate-house roof and down the stairs.

Having extracted presumably the correct symbolic arrow, the Suren pulled his bow from its case. He was just notching the arrow when came the terrifying loud twang, slide, thump of a ballista being released. To his credit, the Suren barely flinched as the bolt shot a few feet above his head. Composing himself, he drew his bow and sent his arrow high over the walls of the town. Then he made his horse rear. The glossy coat of the stallion shimmered as it turned on its hind legs. The Suren called over his shoulder.

'Do not eat all the smoked eel, northerner. My kyrios is very fond of smoked eel.'

Ballista called for the rest of the artillery to shoot. As the Suren and his magnificent mount disappeared back up the road, the missiles arched over their heads but fell some way short of the watching Sassanid army.

'Clever,' said Acilius Glabrio. 'Very clever to pre-empt their barbarian declaration of war with an impromptu version of our very own Roman ceremony of throwing a spear into enemy territory.' The ever-present sneer dropped from the tribune's voice as he went on. 'But if you have tricked them into thinking the range of our artillery is only about 300 paces, that is far cleverer.'

Ballista nodded. Actually, he had been thinking of something else, of Woden the Allfather casting his spear into the ranks of the Vanir in the first ever war. And, from the very first war, it was a very small step to thinking of Ragnarok, the war at the end of time, when Asgard will fall and death come to man and gods alike.

Ballista was leaning on the wall of the terrace of the palace of the Dux Ripae. He was looking down and across the river. He was looking at something horrible.

Where had the woman come from? He had had cavalry methodically sweep the opposite bank, driving everyone they found down to the boats and back across the river. Peevishly he thought that it had not been easy getting two turmae of cavalry ferried back and forth across the Euphrates. Of course, some fools will always stay in the false delusional safety of their homes, no matter with what certainty you tell them of the horror that man or gods are about to visit on them. Maybe the Sassanids had brought her with them.

Every now and then the horse archers would pretend to let her get away. She would run towards the river. Before she got there, the horsemen would ride her down. They would throw her to the ground and another two or three of them would rape her. There were about twenty of them.

With none of his usual noises, Calgacus leant on the wall beside Ballista. 'They are all inside. For once Acilius Glabrio was on time. So were Turpio, Antigonus and the four centurions you told to come. It was Mamurra who was late.'

Both men looked across the river.

'Bastards,' said Ballista.

'Don't even think of trying to save her,' said Calgacus. 'It is just what they want. She would be dead by the time you got any troops into a boat, and then your men would land into an ambush.'

'Bastards,' said Ballista.

They both continued to look over the river.

'It's not your fault,' said Calgacus.

'What?' The silence of the Caledonian's arrival should have warned Ballista that something was coming.

'What is happening to that poor girl over there… the fact that this city is being besieged and, no matter what, lots of its people are going to suffer and die… what happened to Romulus and those scouts… none of it is your fault.'

Ballista briefly pulled an unconvinced face but his eyes remained fixed over the river.

'You have always thought too much. Since you were a child. I am not saying it's a bad thing in itself, but it is no help to a man in your position.' Ballista did not respond. 'All I am saying is that if you give yourself over to sentiment, then you will not be thinking clearly, and then things will get still fucking worse.'

Ballista nodded and straightened up. As he unclenched his hands from the wall, he saw his palms had brick dust embedded in them. He rubbed them together.

On the other side of the river the men had encircled the woman. One of them was on top of her. Ballista looked away.

'I suppose you are right.' He looked up into the sky. 'Only just over an hour to nightfall. Let's go in and talk to the others. We have a lot to organize for the unpleasant surprise that is going to befall the King of Kings tonight.'