Marcus trembled at the thought. Not just out of fear for himself but also for his mother. Without him, what hope did she have? If Caesar were to find her after discovering Marcus’s identity, then surely she would be killed too in the name of revenge?

There was a further matter that disturbed him. He had no wish to take part in any campaign against rebel slaves. If anything, he would rather fight alongside Brixus, against those who made people into their property. It was a doomed cause. Even if Brixus were to unite the bands of runaways and brig-ands, what hope would they have against the might of Rome? Caesar was desperate to crush them as quickly as possible. Even though he said he would only need five thousand men, the equivalent of one legion, there were three more legions he could use as reinforcements. The slaves’ only hope would lie in finding an inspirational leader who combined the qualities of a great warrior, a wise general and a formidable personality. In short, a man like Spartacus. With such a man to lead them tens of thousands of slaves would escape to swell the ranks of the rebellion, and at last Rome might meet her match. But Marcus was still a boy. If Brixus had plans for him to follow in his father’s footsteps, then he would surely disappoint.

Marcus felt a sick sensation in the pit of his stomach. He felt trapped. He was marching to battle at the side of Caesar, to fight slaves whose fate he had once shared. And all the while he would live in fear of Caesar discovering his secret. If Brixus was captured and brought before the victorious Roman general, he’d be sure to recognize Marcus. Would he then betray him, either openly, or under torture?

The more he thought about it, the more anxious Marcus became. Once he had completed his packing, he extinguished the oil lamp and lay down on his bedroll to get some sleep. On the other side of the room Lupus lay on his back, snoring lightly. Marcus folded his arms behind his head and stared up into the darkness. Despite everything that had happened to him since being torn from his home and family, he knew that his greatest challenge lay ahead.

The small party of horsemen left Rome by the Flaminian gate at first light. Caesar wore a plain brown cloak as he rode at their head, not wanting to attract attention. He had written a brief note to the Senate, announcing that he had set off to destroy the rebels. By the time it was read out, the riders would be many miles from Rome and it would be too late for his political enemies to summon him to explain his plans. Cato and his allies would have been sure to use every trick in the book to delay Caesar. It surprised Marcus how often politicians put the advantage of their faction above the interests of Rome as a whole.

He cast a glance at Caesar riding at the front of the column. He was even more ambitious than the rest, keen to crush the new slave rebellion quickly so that he could proceed to win glory for himself in Gaul. Despite his misgivings about his former master, Marcus knew that Caesar always rewarded those who served him well. Marcus’s victory in the fight against Ferax outside the Senate House had added to Caesar’s reputation, enabling him to pass new laws improving the lives of ordinary Romans and removing some of the bitter tensions in Rome that could lead to a new civil war. Marcus had every intention to remind Caesar of his promise to help free Marcus’s mother from slavery in return, and that meant staying at his side.

Marcus was riding with Lupus at the rear of the column. Having been raised on a farm, he had learned from an early age how to mount and ride a pony. By contrast Lupus was a poor horseman. He clung to his reins and leaned forward against his saddle horns as if he might fall from his mount at any moment.

‘Sit up straight,’ Marcus advised. ‘The saddle horns will hold you in place. If we have to break into a trot or gallop, then clamp down on your thighs and heels and hold on.’

Lupus shot him a cross look. 'Easy for you to say.’

‘Surely you’ve ridden before?’

‘Oh, yes. I’ve had a few goes on the cook’s mule, and some of the ponies on the master’s country estate last year. But that’s all.’

‘I see.’ Marcus sucked in a breath to cover up his disappointment. ‘Well, I’m sure you’ll get the hang of it soon enough.’

‘Thanks for the encouragement,’ Lupus replied tersely, as he hunched forward again and gripped the reins for dear life.

The road soon left Rome behind and as they crested the brow of a hill Marcus turned in his saddle to look back. Grey clouds were approaching from the west and already the great city was in shadow. The city comprised an ugly sprawl of buildings covering the seven hills, above which hung a filthy pall of woodsmoke. Marcus was glad to be out in the fresh air of the country with its clean scents. He would not miss Rome. Aside from the discomfort of its gloomy alleys, stench and the constant noise, there was the danger of street gangs and the bloodthirsty fickleness of the mob, as well as the endless plots and conspiracies of politicians. With a click of his tongue, he urged his horse forward and caught up with the rear of the column as it continued east, towards the snowcapped slopes of the Apennines.

It had been an unusually cold winter. The open countryside was bleak and the seasonal trees were stripped bare of leaves and stood gaunt and still, like splintering cracks against the leaden sky. The frequent showers of rain and a passing storm had left the fields waterlogged, while puddles gathered in the ruts and dips of the road. At first there were plenty of farms and village along the route, their inhabitants living comfortably off the crops, fruit and meat that they sold at the markets in Rome. But as the day wore on, there were fewer buildings visible and they rode through unspoiled woods interspersed with much smaller farms and the occasional cluster of rural dwellings that could scarcely be called villages. The ruddy-faced inhabitants, who were outside cutting firewood or taking winter feed to their animals, paused with curious, and sometimes suspicious, expressions to watch the riders passing by and then continued with the unchanging routines of country existence.

After a brief rest at noon they set off again. The road entered the foothills of the mountains that ran down the spine of Italia, just as the clouds darkened the skies above, and with them came the first drops of rain. The riders hunched down inside their capes and pulled the hoods up as the rain pattered on the road. Marcus hoped that it might be a passing shower, but the rain continued to fall, and grew heavier. Despite the animal fat that had been worked into the cloaks to help waterproof them, it was not long before the riders were soaked through. The air was already cold and now the gentle breeze made it even colder.

Marcus could not prevent himself from shivering as he gripped the reins and clenched his teeth in concentration. He spared a glance at Lupus and saw that his companion was shaking uncontrollably as his teeth chattered.

Lupus caught his eye. ‘Wh-when is the master going to stop and take sh-sh-shelter?’

‘What shelter?’ Marcus gestured at the landscape on either side of the road. There was nothing but rocks and stunted trees to be seen, and ahead the road entered a dense forest of pine trees. ‘Perhaps up there.’ He pointed at the treeline.

But when they reached the forest Caesar continued riding, and while Lupus muttered curses at his master, Marcus resigned himself to the discomfort and misery of the journey. The road continued through the trees and, as the slope increased, the route began to zigzag up the hill into the grey mist that shrouded the view of the surrounding landscape.

As dusk encroached on the dismally lit world, the horsemen finally reached the gates of a small town. Caesar presented his senator’s ring to the cloaked sentries and they were ushered through the gate and into the street beyond. There were only a handful of travellers’ inns in the town and only one of those large enough to take the entire party and stable their horses. Night had fallen before the needs of the mounts had been seen to and then Marcus, Lupus and the others joined Caesar and Festus inside where they sat at a bench close to the fireplace sipping heated wine. They had already changed into dry clothes, and their riding cloaks, tunics and boots were drying by the fire.