Vettius beamed happily. Looking after his sick mistress made him most uneasy. Now that she was recovered, all was well with the world once more. Picking up his club, he bowed and left her.

Watching his massive back disappear down the corridor, Fabiola wished that her outlook on life was so simple. A few dozen steps from the Lupanar, Tarquinius was squatting in much the same position he'd occupied for a time eight years before. The spot brought back mixed memories. Back then, he had been waiting for Rufus Caelius, the malevolent noble who had killed Olenus. Unsurprisingly, every moment of the melee outside the brothel was crystal clear. He tried to block out the recollection of his single knife thrust, which at the time had felt so right. Although the haruspex felt it was destiny that had guided his blade, he was still being tortured by the consequences of his action, and the look in Romulus' eyes when he'd told him. Which was partly why Tarquinius found himself here once more, pretending to be a beggar.

It was strange how life worked in circles, he thought.

Fabricius had been as good as his word, taking Tarquinius down to the little fleet in Rhodes harbour. He'd insisted that his fellow devotee should travel on his own ship, the lead trireme. Tarquinius had accepted with alacrity. It seemed perfect: after Mithras' intervention, a passage back to Italy in relative comfort, with possible access to the ancient documents and artefacts he needed. Soon after their departure, though, the haruspex had discovered that most of the items that he wished to look at were on the other vessels. In a stroke, half his plan came undone. He had hoped on the journey to spend as much time studying as possible. In the event, however, the cargo arrangements were a blessing in disguise. When an autumn storm struck the fleet off the island of Antikythera, it was the ships laden with precious goods which sank, not the one with Fabricius and Tarquinius on board. Not that their trireme escaped unscathed. Braving waves taller than a block of flats, and hours of terrifying thunder and lightning, it finally limped into Brundisium with only the stump of its main mast remaining. At least a dozen members of the crew had been washed overboard.

Unharmed against all the odds, the haruspex chose to interpret his good fortune as most would. A deity – Mithras – was guiding his way. Although Tarquinius no longer knew what his purpose was, here was clear evidence that he had one still. He was grateful for this. Rome was where he needed to be.

Fabricius was also thankful to the warrior god. Nonetheless, he made an offering at the temple to Neptune before they left Brundisium. 'Got to keep them all happy, haven't you?' he muttered. Like the Etruscans, Romans commonly worshipped a number of divine beings, depending on their need. Tarquinius was no different.

Reaching Rome, the centurion had taken him to a large house on the Palatine Hill. 'I can do no less,' he had insisted. 'It's a place to rest your head.' The building turned out to be the headquarters of a group of veterans, all followers of Mithras. There, in the underground Mithraeum, Fabricius introduced Tarquinius to Secundus, the Pater of the temple. Stunned by the presence of a Mithraic shrine in the heart of Rome, the haruspex had been even more astonished to recognise in Secundus the one-armed veteran he'd met outside the Lupanar years before. In contrast, the Pater had seemed unsurprised.

Meeting Fabricius and surviving the storm had substantially restored Tarquinius' faith in the gods. Just when it seemed that the obstacles in his way were too immense to overcome, they were removed. During the journey, he'd continued to see occasional images of Rome under a stormy sky. Clouds the colour of blood told the haruspex that someone's life was in danger, but he had no idea who. The vivid dream about the murder at the Lupanar did not go away either, and so the brothel was Tarquinius' first destination once he'd had a night's rest.

Recognising Fabiola soon after arriving, Tarquinius was surprised to discover that she was the Lupanar's new owner. Why she had bought the brothel, no one knew, but the knowledge gave him somewhere to start. Had she something to do with his nightmare? He'd also discovered that Fabiola was the lover of Decimus Brutus, one of Caesar's right-hand men.

The haruspex didn't go bowling in to introduce himself as a friend of her brother, though. That wasn't his style. Instead Tarquinius sat outside, watching who came and went, gaining an understanding of what was going on. Within a few hours, he knew that all was not well in the Lupanar. The brothel was renowned throughout the city for its prostitutes' abilities, yet scarcely ten customers crossed its freshly painted threshold each day. It also seemed to have a disproportionately large number of armed guards, bullet-headed thugs armed with staves, knives and swords. These patrolled the almost empty street, eyeballing anyone bold enough to glance their way. To avoid their attention, Tarquinius had adopted the mien of a drooling, twitching simpleton. It worked nicely; the heavies gave him a wide berth.

This afforded him the time to consider what he was seeing. In Tarquinius' mind, the guards' strong-arm tactics weren't enough to explain the Lupanar's parlous state. They were there as a response to a threat, and those who wanted sex wouldn't be put off so easily. Important men were still visiting the brothel too – he'd heard passers-by mentioning Marcus Antonius' name as a burly figure had gone in that morning. Antonius' must have been a brief encounter, Tarquinius concluded. Less than a quarter of an hour had elapsed before the grinning Master of the Horse emerged. No one had troubled him either, other than another noble. A pleasant-faced man of average build, he appeared most displeased to see Antonius. Could the danger he saw refer to either of them? Tarquinius wondered. What did it matter, unless it impacted on Fabiola? He felt frustrated and fascinated at the same time. If Romulus' sister was in peril, though, he felt a duty to help.

More was revealed at midday as he hobbled away in search of some food. In the surrounding streets, the haruspex noticed different groups of armed ruffians standing around. Directed by a stocky, brown-haired man in a mail shirt, they formed checkpoints reducing, or preventing, access to the Lupanar. Only the most insistent pedestrians – such as a plain-faced woman in middle age he'd just seen – managed to get past. It wasn't difficult to come to the conclusion that some kind of turf war was going on.

Tarquinius still wasn't sure if he should get involved.

Best to wait and watch instead. Morose, Fabiola was sitting at her desk in the reception area when Docilosa returned. It was near sunset, which meant that her servant had been gone for several hours. By the happy look on her face, the visit had gone well. Seeing Fabiola, her features stiffened.

'You've recovered then?' she asked with a show of concern.

The expert needling made Fabiola's hackles rise. 'Yes,' she snapped. 'No thanks to you.'

Docilosa made a small contemptuous sound and brushed past, into the corridor. 'I'll be out the back, washing clothes,' she said.

Furious, Fabiola bit her tongue rather than respond further. The anteroom a few steps away was full of prostitutes who would be listening to every word. Jovina was lurking about somewhere too. The less said in public, the better. Yet the situation could not continue in this manner. It would have to be resolved one way or another, and soon. Fabiola's nostrils flared. Docilosa's friendship was valuable to her, but not under conditions like these.

Before she could do any more, a trio of wealthy merchants from Hispania rolled in the door. Fabiola stood up to welcome them. Well-oiled, they insisted on recounting their story. After a hard week of selling their goods, they'd celebrated by going to Caesar's games that day. A drinking session followed that, and now, the Spaniards declared to Fabiola, they wanted the fuck of their lives. No street gangs were going to stop them visiting the Lupanar, which they'd heard of in their home country. 'You've come to the right place, gentlemen,' Fabiola purred, instantly spotting the heavy purses on their belts. Quite the madam now, she called the girls out to be inspected.