At once the shocked legionaries had begged their general to have them back, to help win the struggle in Africa. Caesar repeatedly demurred, even starting to leave, but their pleas grew more frantic. Promises were made that he would need no other troops to achieve victory. With masterful reluctance, he had accepted the service of all except the men of the Tenth. It, Caesar's most favoured and rewarded legion, had disappointed him most, so its soldiers had to be let go. With their huge pride in their unit called into question, the Tenth's veterans had demanded that Caesar decimate them, as long as they were taken back into his army. In a final gesture of magnanimity, he had given in, welcoming the Tenth to his bosom like wayward children, and ending the rebellion at a stroke.

When he heard the story, Romulus' admiration for Caesar soared. For months, Petronius had filled his ears with talk of Alesia, Pharsalus and other victories. In Pontus, he'd seen with his own eyes what Caesar could do, but this quality made him unique. Not only could Caesar lead armies into battle against terrible odds and win, he could lead men like no other. Crassus had been the polar opposite of this, commanding in an impersonal and uncharismatic manner. Even though he had only served under Caesar for a short time, Romulus was glad he had had that experience before he died.

Once the mutineers had been dealt with, there was no further delay. Caesar headed into the capital to meet with the Master of the Horse and the Senate. The Sixth was demobbed for the moment, its soldiers beating an instant path to the local taverns and brothels. After a few days, they would go home to their families. The prisoners were disposed of the same day too. With a dozen soldiers as escort, the centurion who had pronounced sentence on the two friends led the group into the city.

Petronius had never seen Rome before, and was amazed by the thick Servian walls, the sheer size of buildings and numbers of people. Romulus, on the other hand, felt a sense of dread as they walked the streets through which he had run errands as a boy. This was not how he wanted to return home. Even the sight of Jupiter's massive temple atop the Capitoline Hill produced only a flicker of joy in his heart, and this small pleasure was drained away by passing the crossroads near Gemellus' house. Despite the financial difficulties which Hiero had told him of, the merchant might still be living there. A dull resentment filled Romulus' belly. He was only a hundred paces from the door of the man whom he'd dreamt for years of killing, and he was unable to do a thing about it.

Finally they neared the Ludus Magnus, the main gladiator school, and old fear made Romulus' heart skip a beat. It was from this place that he and Brennus had fled, unnecessarily as it turned out. It had been Tarquinius who killed the fiery nobleman, not Romulus. By now, his initial fury at the haruspex' revelation had crumbled to a lingering bitterness at what might have been. It was hard to feel otherwise. Brennus could still have been alive if they hadn't run, and they might both have earned the rudis. Yet Romulus was not naive: underneath lay the knowledge that Tarquinius would have acted as he thought best – and according to the wind, or the stars. Had his accurate divinations not been a comfort through the ordeals of Carrhae and Margiana? After so long together, Romulus knew the haruspex well; he did not think Tarquinius was a man to act maliciously.

The realisation helped him to square his shoulders as he read what was inscribed on the stone over the main gate: 'Ludus Magnus'. The first time Romulus had seen them, as an illiterate thirteen-year-old, he'd only guessed the two words' meaning. Thanks to Tarquinius, though, he could now read them. It was odd that they were here, thought Romulus. There were four ludi in Rome, yet here he was, outside his old training ground. An ironic smile flickered across his lips as the centurion demanded entry.

A moment later, their hobnailed caligae echoed in the short corridor which led to the open square within the thick walls. It was mid-afternoon, and dozens of gladiators were engaged in physical training with each other and against the pali, the thick timber posts as tall as a man. Trainers armed with whips walked among them, pointing and shouting commands. With wicker shields and wooden weapons that were twice the weight of the real thing, the fighters danced around each other, thrusting and stabbing. Romulus recognised none of them, and his heart bled. Sextus, the little Spaniard, and Otho and Antonius, two other friendly gladiators, were probably all long dead. It was also likely to be true of Cotta, his trainer. He scanned the balconies for Astoria, Brennus' Nubian lover, but there was no sign of her either, only the menacing shapes of the lanista's archers, watching for any signs of trouble. It was not that surprising that Astoria wasn't around, Romulus thought gloomily. Memor would have sold her to a brothel.

Romulus' attention was drawn back to the present by other familiar classes of fighter – Thracians with their square shields and curved swords, and murmillones in their distinctive fish-crested helmets. There were even two pairs of retiarii sparring against the same number of secutores, his own former category of hunter. He stopped for a moment to watch. Instantly, there was a sharp prod in his back. 'Get a move on,' snarled one of the legionaries, poking him again with his pilum. 'Follow the centurion.'

Romulus swallowed his anger and obeyed. Soon he and the others were lined up in front of a familiar figure, one whom he'd never thought to see again. Memor, the lanista. The years hadn't changed him that much. Maybe his skin was a darker shade of brown, thought Romulus, and his shoulders slightly stooped, but the lanista's mannerisms and the way he ordered the gladiators about were exactly the same as before. So was his sarcastic manner. Romulus' stomach clenched. Would Memor recognise him?

'What have we here?' the lanista drawled. 'Deserters?'

'Cowards mostly,' the centurion replied. 'They ran away in the middle of a battle.'

Disapproving, Memor flicked his whip along the ground. 'They'd be no damn good as gladiators then. Why weren't the dogs crucified?'

'The games celebrating Caesar's recent victories are short of recruits,' growled the centurion. 'They are to be classed as noxii.'

Memor's lip curled. 'Not my usual line of business, that.'

Only because there's no money in it for you, thought Romulus sourly.

'Taking them on would be seen as a favour to Caesar himself,' responded the other.

At once Memor was all beams and smiles. 'Why didn't you say? It would be my honour to prepare the sons of whores for death. I might even be able to make them perform well.' He gave the prisoners an unpleasant stare. Oddly, it stayed longest on Romulus and Petronius. 'Why are those two here?'

The centurion snorted. 'One is a damn slave who had the cheek to join the legions.'

Memor's bushy eyebrows rose. 'And the other?'

'His fool of a friend. Tried to defend the slave when he was exposed.'

'Interesting,' said Memor, pacing before the chained men in an appraising manner. His whip trailed after him, its weighted tip drawing a line in the sand. He came alongside Petronius, staring at him like a leopard looks at its prey.

The veteran met his gaze with contempt.

'Still proud, eh?' Memor grinned. 'I can soon change that.'

Petronius had the wisdom not to answer.

Memor moved to stand before Romulus, who, keen not to be recognised, looked away. But the grizzled lanista grabbed his jaw and twisted his head around, making Romulus feel thirteen years old again. His deep blue eyes met the black pits that were Memor's, and they stared at each other for a long moment. 'Which is the slave?' Memor asked abruptly.