'Shield up. Thrust. Step back,' the boy muttered. 'Shield up. Thrust.

Step back.'

Next Juba handed over the shield. Romulus slipped his left arm into the smooth leather grips, hefting the unfamiliar weight. The Nubian showed him how to protect chest and face, keeping his weapon ready for an opportunity to strike.

After a moment, they began to spar in slow motion, Juba taking care not to strike Romulus' wooden sword too hard with his own of iron. The knocking of blades echoed down the hall, and soon Fabiola arrived to watch.

'What if the master catches you?' Her face was a picture of concern. 'Stop it, Romulus. I'll tell Mother!'

'Go away! I'm learning to fight like Spartacus!'

His sister watched with a mixture of pride and fear. 'It's too dangerous. Please stop!'

Suddenly the idea of holding a real sword to Gemellus' neck came to him. Romulus redoubled the attack on Juba, who fell back, a wide grin splitting his ebony features.

It would be the last time he ever practised with the Nubian. When they had finished, Romulus returned to the family's small cell, bursting with excitement. Images of freeing all the household slaves and killing Gemellus now filled his mind. It terrified and exhilarated him.

Chores over, that night Velvinna listened to her son recount Pertinax' tale yet again.

'Be careful, Romulus,' she said, her voice full of pride. 'Nobody must see you with a sword, especially Servilius. Gemellus will not stand for it.'

'Don't worry, Mother.' Romulus' eyelids drooped with tiredness as Velvinna pulled the blanket over his shoulders. 'Nobody knows.'

Exhaustion brought him sleep at once, and dreams of being a soldier in Spartacus' army.

Romulus was rudely awoken the next morning when cold links of metal fastened around both wrists. Confused, he found they had been bound with a light chain. The boy sat up and gazed round the room, terror replacing the alarm. Fabiola and his mother were motionless in their beds, staring at Gemellus.

The merchant stood in the doorway, flanked by Ancus and Sossius, two burly kitchen slaves. Neither would meet Romulus' eye. Most of the household had known him since he was a baby.

'Try and use a sword under my roof? Little bastard!' Gemellus spat. 'Then stab me in my sleep, no doubt. I've been soft far too long. It's the gladiator school for you. Today.' A smile flickered across his lips. 'Learn how to fight there.'

Romulus knew instantly that his life as a common slave had come to an end.

'No, Master, please.' Velvinna threw herself at Gemellus' feet.

Fabiola sat bolt upright, her face stricken. This was just what she had feared.

'Get up, bitch.' Gemellus hauled Velvinna up by the hair. She cried out in pain, but the merchant backhanded her across the cheek and she fell back on to the cot, sobbing.

'Take him.' Gemellus gestured.

The end of the chain extended several feet beyond Romulus' wrists. With a powerful yank, Ancus pulled him out of bed and on to the floor.

Tears filled Fabiola's eyes.

'My son!' Velvinna screamed.

'Useless whore. You'll never see him again,' sneered Gemellus. 'I'll be back for his sister later.'

'Don't worry, Mother.' The words rang hollow, but Romulus did not know what else to say.

She wailed and cried even louder. Everyone knew what entering gladiator school meant.

'Let's go. I can't listen to this.' Gemellus turned and led his men out of the room.

'It wasn't me who told on you!' Fabiola's voice was frantic. 'Romulus!'

'Take care of Mother!'

As Romulus opened his mouth to shout again, Gemellus gestured at Sossius, who turned back and slammed the door shut.

More sounds of distress echoed down the hallway as he was marched off, clad only in his loincloth. Romulus knew Fabiola would not lie. They were far too close. One of the others must have seen Juba training him and informed to curry favour. Servilius?

Slaves had no choice in their lives; they could be bought and sold at will. But Romulus had never imagined leaving Gemellus' possession – he had known no other life. He was torn between fear and excitement at what was happening. While the prospect of becoming a fighter was thrilling, he would probably never see his family again. Romulus looked back one last time, Velvinna's sobs tearing at his heart, wishing his weapons practice with Juba had been quieter. But the man holding the chain was twice his size.

Stories were frequently told in the kitchen about famous gladiators who fought barbarians and wild beasts in the arena. Romulus had always enjoyed listening to the tales, but had never been inside a training school and seen the reality. For a moment, his heart began to race, full of romantic ideas about being one of the people 's heroes.

Sensing something, Gemellus cuffed him across the head. 'A boy like you will be dead inside a month.'

Romulus' heart sank. Of course. What chance would a thirteen-yearold have against professional gladiators?

'You'll need to prove yourself damn quick.'

They had reached the alcove by the front door. Romulus saw with alarm that the Nubian was not in the usual spot.

'Think I'd keep anyone who teaches others to fight?' Gemellus laughed. 'The brute 's on his way to the Campus Martius right now.'

He gaped at the merchant, confused.

'To be crucified.'

Romulus lunged at Gemellus, eyes full of murderous rage.

Ancus pulled reluctantly on the chain, stopping the attack before it even started. Romulus stumbled and fell heavily, all too aware he could do nothing to save Juba.

Gemellus kicked him in the belly. 'Born a slave!' Another kick followed. 'Die a slave. Now get up.'

The door creaked open and the merchant led the way outside. No one paid any heed to the little party. It was common practice to shackle slaves outside the home.

Romulus remembered little of the walk. Still winded, he followed numbly, mind awash with grief and guilt at Juba's fate, whose only crime had been teaching him how to use a sword. Now he was responsible for a man's death. For the sale of Fabiola. What would happen to his mother? How long would he last in the savage world of the arena?

All four lives had been turned upside down overnight. Romulus blinked away tears. Show the bastard no weakness. Be strong, like Fabiola. He took a deep breath in, concentrating hard, trying to release the guilt. Jupiter protect me. Look after my family.

By the time Gemellus reached a set of iron gates set into an archway, Romulus had regained some control of his emotions. Red-eyed, shoulders broad, he was determined to remain courageous.

A square stone was set into the bricks over the entrance, inscribed with two words. Although he could not read, Romulus knew their meaning. It was the Ludus Magnus, largest of the four gladiator schools in Rome and a supplier of men for Milo's gangs.

The bare-headed guard outside wore a battered chain mail shirt reaching to mid-thigh. Leaning against the wall behind was a long spear. A short stabbing sword was ready on the man's belt; a sturdy rectangular shield decorated with a strange emblem hung from his left arm.

'State your business.'

'I want to sell this brat to Memor.'

He looked Romulus up and down. 'Bit young, isn't he?'

'What has it to do with you?' Gemellus snapped. 'Let us inside!'

Sullenly the guard pulled open the nearest gate a fraction, just enough space to enter. As soon as they had passed inside, it clanged shut.

Romulus' pulse quickened at the finality of the sound. Many of the inmates were criminals, hence the sentry. For most, entry to the ludus was a death sentence, a career that only the very best survived for more than a year or two. His dreams of glory had been ludicrous, but he could not suppress a shiver of excitement.