‘Who owns the house?’ Fabiola asked. This was a far cry from the type of accommodation most citizens could afford.

‘Better than an army barracks, eh?’ laughed Secundus. ‘It belonged to a legate, lady. One of us.’

She frowned. ‘Belonged?’

‘Poor bastard was thrown from his horse two years ago,’ he answered. ‘Left no family either.’

‘And you seized his property?’ It was not unheard of for this to happen. In the current uncertain political climate, those who acted with confidence often got away with totally illegal acts. It was how Clodius and Milo had conducted their business for years.

He regarded her sternly. ‘We’re veterans, not thieves, lady.’

‘Of course,’ Fabiola muttered. ‘I’m sorry.’

‘The domus belongs to Mithras now,’ he said simply.

‘So you live here?’

‘We have that privilege,’ Secundus answered. ‘This is the most hallowed ground in Rome. It has to be protected.’

Leaving his men and the statue of Mithras behind, Secundus took them along the corridor and around what would be the corner of the central courtyard. Beneath their feet was a simple but well-laid mosaic, its pattern the typical Roman concentric circles, waves and swirls. Few of the many rooms they passed seemed to be occupied, their open doors often revealing bare walls and floors, devoid of furniture.

Secundus finally came to a halt before a chamber which smelt strongly of vinegar, the main cleaning agent used by Roman surgeons. ‘Janus!’ he cried.

Ushering Sextus in, Fabiola entered the valetudinarium, the soldiers’ hospital. As she would learn later, it was laid out just as it would have been inside a tent in a marching camp. A low desk near the doorway formed the reception area. On a wall behind were wooden shelves covered with rolls of calfskin, pots, beakers and metal instruments. Open chests on the floor were full of rolled blankets and dressings. Neat lines of low cots lined the back of the large room. All were unoccupied. Near them stood a battered table surrounded by a number of oil lamps on crudely fashioned iron stands. Thick ropes hung from each of its legs and while clean, its surface was covered in dark, circular stains. They looked rather like old blood.

Standing up from his leather stool in the corner, a thin-faced man wearing a worn military tunic decorated with two phalerae bowed his head courteously at Fabiola. Like all the soldiers, he wore a belt and a sheathed dagger. The studs of his caligae clashed gently off the floor as he approached.

Respect filled Fabiola. Every single one of Secundus’ men might initially look like a vagrant, but they all carried themselves with a quiet dignity. ‘What’s that?’ she asked, nodding at the table.

‘The operating theatre,’ replied the brown-haired medical orderly.

Fabiola’s stomach clenched at the thought of being tied down and cut open.

Janus ushered Sextus towards it. ‘An arrow?’ His voice was low, authoritative.

‘Yes,’ muttered the slave, bending his head to allow a proper examination. ‘I pulled it out myself.’

Janus clicked his tongue disapprovingly, his fingers already probing the area for further damage.

Secundus saw Fabiola’s surprise. ‘The barbs scrape off flesh as they come out. Makes a ragged and very distinctive wound,’ he explained. ‘Knives or swords come out more cleanly.’

She winced. Romulus!

‘In the legions we see them all, lady,’ Secundus murmured. ‘War is a savage business.’

Her composure cracked even more.

Secundus grew concerned. ‘What is it?’

For some reason, Fabiola felt unable to conceal the truth. The gods had brought Secundus into her life twice in just a few days; as a veteran, he would understand. ‘My brother was at Carrhae,’ she explained.

He shot her a surprised glance. ‘How did that come to pass? Did he belong to Crassus?’

Of course, he knew her past: that she had been a slave. Fabiola peered anxiously at Janus and Sextus, but they were out of earshot. The orderly had made her slave lie down on the table and was cleaning the blood from his face with a wet cloth. ‘No. He escaped from the Ludus Magnus and joined the army.’

‘A slave in the legions?’ barked Secundus. ‘That’s forbidden, on pain of death.’

Romulus had not been discovered and executed for that reason, thought Fabiola. As crafty as she, her twin would have found a way. ‘He was with a Gaul,’ she went on. ‘A champion gladiator.’

‘I see,’ the veteran answered thoughtfully. ‘Might have joined a mercenary cohort then. They’re not as picky.’

‘Romulus was a brave man,’ Fabiola snapped, bridling at his words. ‘As good as any damn legionary.’

‘My words were hasty,’ he admitted, colouring. ‘If he is like you, he must have had the heart of a lion.’

Unwilling to let it go, Fabiola pointed at Sextus. ‘Look! He’s a slave. Yet he fought for me when badly wounded. So did the others, before they were killed.’

Secundus lifted his hands in a placating gesture. ‘I am not what you think.’ He looked her in the eyes. ‘Slaves are permitted to worship Mithras. With us, as equals.’

It was Fabiola’s turn to feel embarrassed. Secundus was not then like the majority of citizens, who regarded slaves as little better than animals. Even manumission did not completely remove the stain: by now, she was well used to the patronising stares given her by many nobles who knew her past. Fabiola sincerely hoped that any children the gods might grant her would not suffer the same discrimination. ‘What do you mean?’

‘Our religion’s main tenets are truth, honour and courage. Those are qualities anyone can possess, whether they are a consul or a low-born slave. Mithras sees all men in the same light, as brothers.’

It was an alien and incredible concept; one Fabiola had never heard of. Naturally, it appealed to her immensely. In Rome, slaves were permitted to worship the gods, but the idea of recognising them as equals to their masters was unthinkable. Their position in society remained the same: the very bottom. The only people who could perhaps have changed that, the well-fed priests and acolytes in the city’s temples, were no more than mouthpieces of the state: they never expressed such revolutionary thoughts. That might upset the status quo, which allowed an elite class of tens of thousands, as well as the ordinary citizens, to rule over hundreds of times that number of slaves. To hear that a god – a warrior god – could see past the stigma of slavery was truly amazing.

Fabiola’s gaze lifted to that of Secundus. ‘What about women?’ she asked. ‘Can we join?’

‘No,’ he answered. ‘It is not permitted.’

‘Why not?’

Secundus’ jaw hardened at her audacity. ‘We are soldiers. Women are not.’

‘I fought today,’ she said hotly.

‘It’s not the same, lady,’ he snapped. ‘Do not presume too much on our hospitality.’

Chapter IX: Omens

Margiana, winter 53/52 BC

Illness had aged Pacorus considerably. The normal healthy colour of his brown skin had still not returned. In its place was a pale waxy sheen, which accentuated his sunken cheeks and the new grey streaks in his hair. The Parthian had lost a huge amount of weight, and clothes which had fitted him well now hung loosely on his bony frame. But, remarkably, he was alive. It was a minor miracle. Despite the high fevers that had racked his body and the foul, yellow poisonous liquids which had repeatedly erupted from his wounds, Pacorus had not succumbed. Scythicon did not kill every man, it seemed. But it was not just his tough nature: all of the haruspex’ skill and another dose of the precious mantar had gone into his recovery.

And the help of Mithras, thought Tarquinius, eyeing the little statue on the altar in the corner. He had spent many hours on his knees before it, making sure when possible that the commander saw him. Half-delirious still, Pacorus had been susceptible to his muttered words and consequently overcome by devotion to his god. With little prompting, he rambled about some of the secret rituals practised by the Parthians in their Mithraeum. The haruspex listened eagerly, picking up valuable pieces of information. He knew now that the statue depicted Mithras in the cave of his birth, slaying the primeval bull. By performing the tauroctony, the god released its life force for the benefit of mankind. Like all killings, the sacred rite did not come without a price, which explained why Mithras was looking away from the bull’s head as he plunged his knife into its throat.