4

We’re going into Pictland? Just us – on our own?’

‘We pick up some mounted scouts at Bremenium, but otherwise, yes, just us.’

‘They’ll cut us to pieces and boil our bones…!’

It was mid-morning, four hours of marching behind them already, and now the men of the century were assembled at the side of the road in the shade of the trees. Castus stood facing them, his staff gripped level in both fists. He had not been looking forward to this little address.

‘Quiet in the ranks!’ growled Timotheus, a moment too late. Genialis’s comment had already raised a stir of agitation. Castus scanned the faces of his men: some looked shocked, disbelieving; others apprehensive. One or two grinned in feigned amusement. But a satisfying number just stared back at him, neutral, trusting to the wisdom of their superiors. As do I, Castus thought. For better or worse.

‘We’re not going to be doing any fighting,’ he said, with heavy emphasis. ‘Our job is to escort those two over there’ – he jutted his staff towards Strabo and Marcellinus, waiting with their horses on the far side of the road – ‘up to meet the Picts and talk things over with them in a peaceful and friendly way.’

A few more grins now, the men nudging each other.

‘So nobody’s getting chopped up and eaten, unless I give you permission. We just march up there, stand around looking Roman, then march back home.’

‘So long as we’re not expected to dance for the Picts, or sing…’

‘No, Atrectus, you’re not. That would be counted as a just cause for war.’

The grins broke to laughter, and Castus allowed himself to relax a little, the tension easing from his shoulders. They were fine now, but they had ten more days of marching ahead of them. He would talk to Timotheus and Evagrius. Important to keep the rumours and the muttering in check, or he would be leading a very unwilling set of soldiers north of the Wall.

‘That’s all. Get into line and let’s move – there’s another four hours yet till we reach Cataractonium.’

They marched for the rest of the day, the road reeling on ahead of them and falling away behind, still straight as an arrow-shot. After a while it become hypnotic, the stretch of packed gravel always ahead, never ending, and the eye came to hunger for a bend, a bridge, anything to break the monotony. Castus didn’t mind, though: easier to march steadily when you didn’t have to think.

But it was impossible to banish thought altogether. He had slept badly at the villa; the bed had been far more comfortable than he was used to, and after a few hours he had got out and stretched himself on the hard tiled floor. The image of Aelia Marcellina had haunted him, the girl’s pale face swimming in the darkness, the memory of her whispering voice, and the promise he had sworn to her. The lack of sleep was unsurprising.

Marcellinus and the secretary kept themselves apart, riding together along the verge of the road, often talking intently out of hearing of the soldiers. Good thing too, Castus thought: he had no wish to know any more about the mission than he had to. They were passing through farmland again now, and a group of field labourers straightened from their work and stood to watch as the soldiers went by. They’re like me, Castus thought: simple men with a simple job. Two generations back he would have been the same as them. That was his blood, his heritage. He had no time for the intrigues of diplomacy.

As they approached Cataractonium, the end of the day’s march, Marcellinus rode up alongside Castus. ‘I believe my daughter spoke to you last night,’ he said.

‘She did, dominus.’

‘I’m sorry about that. I had forbidden it. Oh, and you can drop the formal address now, brother!’

He slid down from the saddle and walked beside Castus with the reins looped over his arm. ‘My daughter is an intelligent girl,’ he said. ‘But she’s imaginative, and that isn’t a good thing in a female. They can become fearful so easily. We only received word from the governor about this… mission a few hours before you arrived, so my family were still rather shocked by the news. Please don’t let my daughter’s words shadow your mind.’

‘Of course not, domin… I mean, I’d forgotten them already.’

‘Good, good. Do you have a wife yourself?’

‘Never had the time.’

‘Probably wise. I feel as I get older that we should live without too many attachments. But I love my family – my wife and my children.’

‘You have other children?’ Castus almost choked on the words – he hoped that Marcellinus was not referring to the murdered boy.

‘Yes, I have a younger son in Eboracum. Didn’t you know?’

Castus shrugged and shook his head. They walked on for some time in silence, and Marcellinus took an apple from his haversack and fed it to his horse.

‘You served in the east, so Strabo tells me. With Galerius in the Persian campaign?’

‘I did,’ Castus told him.

‘That must have been something to experience. Galerius is quite the tactician, so I hear.’

‘I suppose so.’ Castus had little concern for tactics: going in hard and heavy, like a charging bull, was his favoured approach, and beating the enemy into the ground by brute force. But he had to admit that Galerius’s planning at Oxsa had been very clever. The emperor had scouted out the terrain himself the day before the battle, so the men had said afterwards, disguised as a cabbage-seller…

‘Tell me about it. It would pass the time.’

‘Well…’ Castus said. He had grown wary, since coming to Britain, of talking too much about his years in the Herculiani. Too many people seemed to think he was just boasting, or to feel lessened by the comparison with their own drab lives. Tentatively, he began to explain the positions at Oxsa, the night march that had brought them round the flank of the Persian royal camp, their battle line on the slopes above the valley. Then the Persian charge, the infantry taking the shock of it, the cavalry sweeping round from the wings… He was not a skilled speaker, and stumbled over the right words, but as he went on he saw the battle once more before him, heard the crash of impact as the cataphracts broke through the forward cohorts. Again he saw the horses rearing out of the dustcloud, over the bloodied wrack of bodies…

‘…then after that we stormed their camp and took the lot – even the ladies from the harem, although Galerius ordered them to be treated with honour. I didn’t see any of it, though. I’d passed out from injuries by then. But I heard about it later.’

‘Must have been a fine sight, a battle like that.’ Marcellinus tipped his head back and closed his eyes, as if he could scent the blood and dust and hear the clash of combat. ‘I would love to have been there.’

Castus glanced at him. His broad faced turned to the sun, his cropped iron-grey hair. This was a man who had commanded troops in battle, he reminded himself, and won great victories. It was strange to speak to him so frankly.

‘I’ve spent my whole life in the western provinces,’ Marcellinus said. ‘Half of it in this damp borderland. Oh, I don’t regret it – I’m rooted here now. But I wonder what I might have made of myself if I’d gone east. Another life, eh?’

‘I suppose so. But you’ve done well yourself, so I heard.’

‘Do you? And what exactly have you heard about me, centurion?’

Castus tightened his jaw, cursing his mistake. ‘Oh, this and that,’ he said. ‘You… won a few battles against the Picts. Strabo told me.’

‘Did he now?’ The envoy’s voice had dropped, grown colder. ‘And how does he know, I wonder? He was in Gaul until eighteen months ago!’

‘I suppose they told him, back at Eboracum.’

‘Yes. I’ll bet they did. Our friend Strabo seems very well briefed indeed.’

They were billeted that night at the town of Cataractonium, and then went on the next day to Vinovium fort. Soon afterwards they entered the hill country, and the road rose and fell across steep ridges and valleys. The sky was dull grey, spitting rain, but the troops marched with silent indifference. On the fifth day from Eboracum they arrived at the military supply depot of Coria, a few miles south of the Wall. Castus gave his men the following day to rest and resupply, and with a free evening ahead most of them filed off at once to the bath-house, the beer shops and the brothels.

The depot commander had allocated billets in a disused cavalry barracks inside the military compound. In his quarters, Castus pulled off his boots and lay on the bed. Evening light came in through the open window, and he closed his eyes and listened to the familiar sounds: soldiers arguing and laughing; the click and rattle of dice from the rough wooden portico; the creak of wagons; and the distant clatter from the armoury workshops. Almost like home, he thought.

Marcellinus and Strabo were accommodated in a house across the street from the compound, and it was a relief to be free of them for a few hours. For the last three days on the road he had watched them, trying to dull his curiosity. Something was going on between the two men, some strange tension that worried Castus like an itch at the back of his mind. Half the time they had ridden apart, as if deliberately avoiding each other, but then they would spend hours in close whispered conversation. Clearly there was little trust between them. It was none of his concern, Castus told himself. And yet… He had the safety of his men to consider, the success of the mission. He couldn’t allow some obscure rivalry or suspicion between the envoy and the secretary to endanger that.

After five days of solid marching he was filled with a punchy energy, and the thoughts revolving in his head would not let him relax. Throwing himself up off the bed, he poured a cup of vinegar wine and drank it down. One of the slaves had left food on the table – fresh bread, pea soup and bacon – and he ate standing, pacing up and down the narrow room as the light faded outside and the first torches glowed in the portico. He cleaned and waxed his boots, then oiled his belts and other kit, and with the last of the light he burnished the rust spots from his helmet with a damp rag and ashes from the fire. Night had fallen, but he did not feel like sleep. He pulled his boots back on, shrugged a cloak across his shoulders and went outside.

Timotheus was under the portico, drinking wine with the sentries.

‘Take over here for a couple of hours,’ Castus told him. ‘I need to stretch my legs.’

‘You haven’t stretched them enough today?’ the optio asked with a smile. They had covered twenty miles since dawn, over steep roads from Longovicium.

‘That was only a stroll,’ Castus said.

Passing between the lounging sentries at the gate of the military compound, he walked out into the muddy central street of the civilian settlement. Dogs ran in the gutters, and light spilled from the open doors of the taverns. Grubby children begged for copper coins in the portico of the market building. It was starting to rain again.

Coria had once been a proper fort, but the ramparts had been torn down years ago and now it was a trading settlement and supply town for the Wall garrison. Beyond the military enclosure with its armouries and storehouses the town straggled along the road in both directions, the home of provisions merchants, craftsmen and prostitutes. Not a cultured or genteel place, but Castus liked the look of it well enough. He paced slowly along the street wrapped in his cape, only his swagger and his army boots marking him out as a soldier. He should check on his men, he thought to himself; there were off-duty cavalry troopers from the Wall forts in town, and plenty of potential for trouble.

By the time he reached the limit of the settlement it was fully dark, and the rain was thin and steady. He turned and looked back along the street. The massive grain warehouses by the market rose up black against the dull glow of the town. He was getting wet, and felt the first waves of fatigue in his blood. Back up the street towards the compound, he passed a group of his own men gathered in the lighted door of a tavern – Atrectus and Genialis laughing as they tipped back their cups, Culchianus playing dice with a group of cavalry troopers just inside – but he kept to the shadows and they did not notice him.

He was almost back at the compound gate when he saw the hooded figure on the far side of the street. There was nothing immediately significant about him – just another local tradesman in a waterproof cape, hurrying home – and Castus might have ignored the man, but there was something familiar about his build and the way he walked. A moment, and he recognised him: it was Strabo. Without thinking, Castus had stepped back into the deeper darkness under the buttresses of the grain warehouse. Where was the secretary going? His quarters had baths, a dining room, and there were slaves to run errands. There was no reason at all for Strabo to venture out into the town alone in the rain. Did he have some strange desire to go drinking with the soldiers, perhaps? Castus considered that he might be on his way to a brothel, but doubted that the dapper secretary would relish an encounter with the sort of hardbitten ladies available in a frontier town like Coria.

Already he was moving, tracing his way along the side of the street. The idea of following Strabo, skulking about after him like an informer, was repugnant; what the man did in his own time was his own business. But Castus had his duty to his own men to consider: if the secretary was doing something suspicious then he had to know, or the thought of it would eat away at him, and in time the men would notice his unease.

He shrank back into the timber portico of a tavern as the secretary crossed the street ahead of him. When he stepped out again the man was gone, but Castus saw the narrow opening of an alleyway. He paced quickly along the wall and peered around the corner. A stink of stale urine met him: the patrons of the tavern had been using the alley as a latrine. But there was the figure of Strabo, briefly visible where the alley widened at the far end.

Treading carefully, steadying himself against a crumbling wall, Castus moved along the alleyway. He had left his sword and staff in the barracks, and the only weapon he carried was a small knife in his belt; in street fights he preferred to trust his fists and physical bulk, but he doubted that Strabo was leading him into that kind of trouble.

He slowed as he reached the end of the alleyway. It opened into a wide courtyard, greasy with slops and ringed with low wooden buildings. At the far side, he could make out the figure of the secretary waiting at a door. A moment passed, and then the door opened: a brief gleam of lamplight as Strabo stepped inside, and then the door closed again behind him.

Castus leaned back against the mossy bricks. If the place was a brothel, it was a very unusual one. Perhaps the sort of establishment that catered for strange tastes? He had heard of such places, in Antioch and even in some of the western cities. But surely not in a rough frontier settlement like Coria? He belched quietly, tasting pea soup.

Crossing the muddy yard in six long strides, he stood before the door. There was no sound from inside, and he gave the planks a careful shove. Bolted, it seemed. As his eyes adjusted to the darkness he saw two symbols scratched into the wood of the doorframe: something that looked like a ship, and below it an X with a line through it, like a solar wheel. He stood breathing quietly, one hand on the door. Strabo might easily spend hours in there, and Castus did not care for the idea of loitering outside in the rain. He could barge the door down and demand to know what was going on, but that would involve crossing a dangerous line. So far, he had just been strolling in the public street. No, he thought, there was no more he could do, and he was feeling very weary now.

He pushed himself away from the door, negotiated the stinking alleyway and headed back towards the military compound, thinking only of the pleasures of sleep.

By the time he found Marcellinus it was the following afternoon. From the door of the storehouse, where Evagrius was arguing with the commissary about a consignment of hardtack, Castus spotted the envoy leaving the depot commander’s residence. Abandoning the standard-bearer to his negotiations, he crossed the gravelled courtyard.

‘Centurion,’ Marcellinus said as Castus dropped into step beside him. Together they walked away from the storehouse into the open ground before the depot gates. Now that he had located the envoy, Castus found it hard to phrase what he meant to ask. Even to admit his suspicions seemed dishonourable, somehow unmanly: he would have felt more comfortable confronting Strabo directly. This kind of subterfuge felt alien to him, but his duty was to the security of the mission. He was just about to speak when Marcellinus cut him off.

‘Are your men prepared to resume the march tomorrow?’

Castus gave a curt nod. Clearly the envoy had other things on his mind.

‘Good. We’ll be crossing the Wall then. First time beyond the frontier for most of them, eh?’

‘There’s a matter I need to discuss with you, dominus.’

Marcellinus paused, laid a hand on Castus’s shoulder and steered him towards the gate of the compound. ‘Very well, we’ll cut the idle chat,’ he said, and something in his tone told Castus that the man had merely been stalling – he knew very well what the question would be.

‘What you make of the secretary, Strabo?’

Marcellinus’s hand tightened on his shoulder, then dropped. ‘I’ve been studying him these last few days,’ the envoy said quietly. ‘But I’m not convinced by what he says. What are your impressions of him?’

‘Not much. He keeps himself to himself.’ Then again, Castus thought, so do you. He did not wish to mention his brief espionage the night before, at least not unless he had to.

‘He’s strange, don’t you think?’ Marcellinus went on in a musing tone. ‘Why was such a man sent on an assignment like this? He’s not a native and he’s only been in the province for a short time.’

Castus was not fooled. The envoy clearly knew more than he pretended, but he wanted to probe for a response without giving away his own position. Castus remained silent. Marcellinus waited a moment more, before turning suddenly, drawing himself up and tipping his head back.

‘Centurion, I’m glad you came to me with your concerns. I wasn’t sure, I confess, whether you knew about our friend Strabo or not… whether you were, shall we say… one of his familiars…’

Castus tightened his jaw at the implication, anger rising in his throat; he was satisfied to see the envoy flinch instinctively and step back.

‘Forgive me,’ Marcellinus said, inclining his head as if in apology. ‘But it’s reassuring to know I’m not alone in my suspicions. It seems I must go and talk to Strabo, man to man, and ask him to explain himself. I would like you to accompany me.’

‘Why?’

‘Because I want the meeting to appear more official than merely personal, perhaps. And because what he tells us might be of great importance once we travel into the north. Will you come with me?’

It was more an order than a request, but Castus nodded. ‘Should I arm myself first?’

‘I don’t think that will be necessary. Hopefully we won’t need to murder him.’

They crossed the street from the compound and entered the house opposite. There were two storeys, built around a little pillared courtyard; Marcellinus tossed his cloak to a slave in the entrance hall and then led Castus up the stairs to a door at the end of the corridor. He knocked and waited until they heard the voice of Strabo from inside.

‘Gentlemen, come in,’ the secretary said. He looked flustered, and quickly dusted the knees of his breeches, as if he had just been kneeling. ‘Can I offer you some wine, perhaps?’

‘No thanks,’ Marcellinus replied. He seated himself on a stool by the window. Castus leaned back against the door.

‘In what capacity were you sent on this assignment?’ the envoy asked, hard and direct. Strabo raised an eyebrow, then he sat down on a divan piled with bedding.

‘As the governor’s representative, of course…’

‘A position of great trust for a mere secretary, no? Tell me plainly, Strabo. What is your rank and station?’

As he watched, Castus saw a swift change come over the secretary: the baffled act fell away, and instead he appeared suddenly more controlled and focused.

‘You tell me, envoy. Since you seem to have your suspicions already.’

Marcellinus smiled. He turned to address Castus now. ‘Centurion,’ he said, ‘have you ever heard of the agentes in rebus?’

‘No,’ Castus replied, shrugging against the door. The title sounded so bland it could mean anything, or nothing.

‘They’re a corps of imperial messengers and investigators. They operate in great secrecy, and take their orders from the Office of Notaries and the emperor himself. One of their agents is placed in every provincial governor’s staff.’

‘Spies, you mean?’ Castus pushed himself away from the door with his shoulders. The top of his head brushed the low ceiling. Strabo was smiling to himself.

‘Not spies exactly, no,’ the secretary said. ‘But your guess is correct, envoy. I am an imperial agent, as you suspect. I was despatched eighteen months ago from the court in Treveris to investigate the loyalties of Aurelius Arpagius, governor of this province. Now I have been ordered to accompany you and… make sure everything proceeds in accordance with the emperor’s wishes.’

‘So why did you go to that house in town last night?’ Castus demanded. He had taken a step forward as he spoke. Marcellinus frowned, raising a calming hand.

‘So it was you that followed me?’ Strabo said. ‘I thought somebody did. But I guessed you would send one of your men, or a slave, rather than do it yourself.’

‘Where did he go?’ Marcellinus asked abruptly, confused. ‘What is this?’

‘He went to a house – I don’t know why. There were symbols scratched on the door. Something like a ship, and a sun-wheel thing. An X with a line through it.’

Marcellinus paused, still frowning. Then he suddenly threw back his head and laughed. ‘Oh, wonderful!’ he cried.

‘What I do, or believe, is none of your concern,’ Strabo said quietly. ‘My loyalties to the emperors are beyond question.’

‘I don’t understand,’ Castus said.

Marcellinus was grinning, teeth clenched. ‘Those were Christian symbols,’ he said. ‘Our friend Strabo is the follower of an illicit superstition!’

‘Such a term proves your ignorance,’ Strabo said, with more anger than his expression suggested. ‘My faith is sincere, as are my loyalties!’

Castus knew little about Christianity. It was a secret religious cult, and its followers denied the gods and the authority of the emperors, and went into tombs to worship the ghosts of executed criminals and eat the flesh of the dead. More importantly, it was illegal. Shortly before the Persian war there had been an order discharging Christians from the legions without honour. Then, a few years later, an imperial edict had outlawed the practices of the cult entirely. But in the military fortresses of the Danube there had been little visible sign of it. Could there really be Christians in Coria? Castus felt a cold churning in his stomach. Such men were clearly deluded idiots, but possibly they were also traitorous, even dangerous. Being in the same room with one now was alarming.

‘To be frank, I’m not too concerned about your faith,’ Marcellinus said. ‘You can believe whatever sordid fantasies you wish. Just keep it to yourself. I trust the centurion here is a tolerant man?’

Castus just grunted. He could only speak for himself, but he worried about the effect on his men if they found out.

‘I’m not afraid of you,’ Strabo said with a cool tone. ‘Believe me, I’ve suffered more for the truth than you can know. But our Augustus Constantius is also a tolerant man, and has shown an inspired lack of the persecuting fervour so common in his imperial colleagues.’

‘So he sent you here, out of the way? Very convenient for everyone. I had believed that the imperial service was purged of all your fellow cultists… But no matter. Now everything’s out in the open. Or is there more you’d like to disclose?’

‘No, nothing more. But, as for my role – we all have our orders. Just like you, envoy. And you, centurion. My own orders require me to keep silent on many matters. I hope you can respect that, as you respect the emperor I am glad to serve.’

‘Very well,’ Marcellinus said, standing up. ‘I’m glad we understand each other, Agent Strabo.’

They reached the Wall of Hadrian at dawn the next day. It was misty, and the fortifications appeared suddenly ahead of them, a hard pale line of stone in all that empty grey. As they drew closer, Castus could make out the huts and sheds lining the road that led up to the single gate. The smell of cooking fires too – neither he nor his men had breakfasted yet, and his guts tightened.

Marcellinus rode forward and spoke to the decurion of the cavalry detachment on guard, while Castus and his men stood and stamped in the damp morning chill. Then the gates swung open, and they moved on along the road into the borderland beyond.

There was no change, at first, in the landscape. Fields to either side, and small farms or homesteads. All this country, Castus knew, had been part of the empire once. Now the tribes of the border were Roman allies, settled and peaceable – or so Marcellinus had claimed. He said that they would meet a party of these tribesmen a day or two further north, who would accompany them to the Pictish chiefs’ meeting. Castus was wary of that idea – far better to keep themselves apart from the locals, he thought. Nobody outside the bounds of Roman control could be trusted. But Marcellinus understood their ways, and they would all have to trust in that understanding now. Castus would also have to trust in the interpreter that Marcellinus had hired at Coria, a weaselly Briton with a nervous twitch, named Caccumattus. The little man claimed to be of the Textoverdi tribe, and to speak the language of the Picts fluently, but his Latin was poor enough for Castus to be dubious of his value.

It was a hard day’s march. The road ran straight as ever, but the horizons rose on either side to bare brown hills, craggy with rock outcrops. The farmland fell away behind them, and they climbed across windy uplands with the sky huge and tumbling with clouds above. At the day’s end they reached the outpost fort of Bremenium, a white-walled bastion on the edge of nowhere. The garrison was made up of frontier scouts, tough wiry men on native ponies, most of them Britons from the mountains in the west of the province. Six of them were ordered by their commander to join the envoy’s party – they would act as forward scouts and guides on the roads ahead.

At dawn Castus assembled his men in formation before the gates of the fort. Fifty-eight blue-black shields emblazoned with the winged Victory emblem. Fifty-eight armoured bodies, fifty-eight upright spears. He drew himself up stiffly before them, throwing his voice to challenge the breeze coming in across the hillside.

‘Men, this is the last outpost of Rome!’ He sounded hoarse, and the wind whined at his back. ‘From now on, whatever you might have heard, we’ll be in enemy country. Remember that, and act accordingly. We might run into some locals along the way, but don’t forget they’re barbarians. Treat them with respect, but keep your distance. And don’t get any ideas about any blue-painted ladies you might happen to meet either – if you want to keep your balls where they’re needed!’

A few smiles, a ragged laugh. Castus had overheard some of the men back in Coria debating the possible wantonness of the native women.

‘We’ve got a hard march still ahead of us,’ he said, raising his voice to reach the men watching from the fort wall. ‘Five days at least. We’ll be camping in the open, so we’ll be making defensive enclosures every night and setting regular watches. You’ve been trained for it, so you know what to do. But keep this in mind, all of you: we’re representing Rome from now on, and the honour of the Sixth Legion. Don’t let your guard down. Don’t get careless. I want you all as smart and tight as you would be on pay parade!’

Pacing before the front-rank men, he scanned their faces as he passed, trying to read their expressions. The optio, Timotheus, stern and alert. Evagrius, with the century standard across his shoulder. Atrectus looking half-asleep. The cornicen Volusius with his big curled horn ready to give the signal. Vincentius and Culchianus frowning beneath their helmets. All of them grey-faced, uncertain behind the mask of duty. Castus glanced away, composing himself. Unconquered Sun, he silently prayed, Bringer of light and life, let me lead these men well. Let me return them all safely when this is done.

‘As I said, this is a peaceful diplomatic mission.’ He smiled, and some of the men smiled with him. He was glad of that. ‘But we’re soldiers, and we’re going into enemy country, so we’re under war discipline from now on. Does everyone understand me?’

A chorus of dull mumbling from the assembled men. Castus slapped his staff into his meaty palm. ‘Speak up!’ he shouted. ‘We’re going to war. Act like it!’

‘Understood!’ the men called back, eagerly now.

A heartbeat’s pause, a glance away at the empty hillsides, the brown heather.

‘Sixth Legion,’ he shouted, ‘are you ready for war?’

‘Ready!’ the traditional cry came back.

‘Are you ready for war?’

‘Ready!’

‘ARE YOU READY FOR WAR?’

‘READY!’

The echo of their voices died over the hillside, into the wind.

‘Optio, form up the men. Cornicen, prepare to sound the advance.’

Behind him, fifty-eight men assembled into marching formation as the slaves drew the pack mules together. The mounted scouts trotted forwards onto the flanks, edging the road. Marcellinus and Strabo nudged their horses into motion.

‘Ad-vance!’

The horn rang out, a sustained double note, and a last cheer went up from the men in the fort as the century swung forward in march step.

They moved off, a small column in the great emptiness of the landscape, dwindling slowly until the sentries on the gatehouse saw them vanish into the far distance and the sound of their marching feet faded to nothing.