Tarquinius waited until they had all stopped. ‘What of the Indians though?’ he asked softly.

Shock replaced the happiness in men’s faces. The five words hung in the air, which had suddenly turned clammy. Romulus glanced at Brennus, who shrugged.

‘The Indians?’ Pacorus laughed, but it rang hollow. ‘They would have to defeat the Bactrians before coming anywhere near Margiana.’

‘They have already done so.’

Pacorus’ complexion turned pale grey. ‘Spring has only just started,’ he retorted.

‘A hundred miles to the south, the snows have melted early,’ came the instant response. ‘And Bactria’s army has been crushed.’

The commander was visibly deflated.

‘A huge army is on the move towards us,’ Tarquinius continued. ‘The Indian king Azes desires more land. Unchecked, he will sweep through Margiana.’

Pacorus’ miserable expression spoke volumes. Tarquinius had mentioned this once, a long time ago. ‘How many?’ he asked.

‘Thirty thousand infantry,’ intoned the haruspex. ‘And perhaps five thousand cavalry. Battle chariots too.’

Shouts of disbelief rose into the air from the nearest legionaries.

‘A small threat,’ growled Pacorus, trying to shrug it off.

Tarquinius’ eyes were dark pits. ‘There are also elephants. One hundred of them at least.’

Now the soldiers began to look scared and the Parthian’s shoulders slumped.

Romulus’ joy at seeing his mentor again began to dissolve. This was the doom of the Forgotten Legion. And of his friends too. He knew it. Wrapped in new misery, he did not notice Brennus’ reaction.

There was a long silence before Pacorus finally regained control of his emotions. ‘Back to barracks. At once!’ he muttered. Morale would be affected if even more was revealed, but judging by the unhappy voices among the ranks of the First, that was already happening.

The centurions and optiones hurriedly obeyed. With kicks and curses, and blows from their vine canes, they got the men moving.

‘We must talk,’ the commander said to Tarquinius.

The haruspex gravely inclined his head. Despite his horrific injuries, there was still an air of gravitas about him.

Romulus and Brennus marched on. Tarquinius’ head turned as they came alongside. Romulus’ eyes and his met, before Tarquinius’ gaze moved to Brennus. He grinned at them, and it was impossible not to respond. The greatest threat to their lives might lie ahead, but they were all still alive.

And then they had tramped past, under the arched gateway and the sentries on the ramparts. A maelstrom of emotions could be felt in the First’s ranks. The legionaries’ elation at their stunning victory had been utterly diluted by the haruspex’ ominous words. After Novius’ accusations, Tarquinius had automatically been tarred with the same brush as Romulus and Brennus. Being incarcerated, no one could accuse him of being an escaped slave, yet he was guilty by association. But kinder memories of the terrible march east from Seleucia were also vivid. That was when Tarquinius had become widely known, nursing the sick and wounded. Moreover, his prophecies invariably came to pass, which had earned him huge respect throughout the Forgotten Legion.

If Tarquinius said that an invasion was imminent, few men would argue.

They would soon need all the luck Fortuna was prepared to throw their way.

Pacorus had indeed taken Tarquinius’ words to heart. That evening, all centurions were ordered to the Praetoria. There it was announced that the legion would march south the next day. Only a small group of warriors and those who were unable to march would be left behind. Every single ballista made by the bored armourers during the quiet winter months was to be taken. Fortunately the tough mules which had accompanied the prisoners east from Seleucia were well fed. Theirs would be a tough job too. As well as food, spare equipment and the engines of war, the pack animals had to carry hay for themselves, the long spears and the tents.

The announcement was quickly disseminated by the grim-faced centurions. Although Parthian, they too were dismayed by Pacorus’ decision. Going on campaign this early in the year was not an appealing prospect. Yet the news wasn’t of much surprise to the weary legionaries. They had been looking forward to celebrating their victory over the Scythians, and the pleasure of sleeping in their own beds. Instead, they were brooding over Tarquinius’ words, which had already been repeated a dozen times in every barracks. One perilous battle was to be followed by another, yet more ominous. As darkness fell, thousands of prayers rose up into the empty, windless sky. Few men slept well.

Romulus in particular lay awake for much of the night, considering his future. It seemed utterly hopeless. Everyone was out for their blood: Pacorus, Vahram, Caius and now the Indians. For every danger that he survived, two more seemed to spring up. As ever, deserting seemed pointless, while trying to rescue Tarquinius was tantamount to suicide. Marching to face the Indians was the only option. South, into the unknown, to a battle that no one could win. A dense gloom enveloped Romulus. But Mithras had seen fit to keep him alive this far, and Tarquinius would be travelling with the legion. Perhaps there was a faint chance.

Brennus did not like talking much. Instead he had fallen asleep and was snoring contentedly nearby, a tiny smile playing on his lips.

Wrapped up in his own troubles, Romulus still did not notice his friend’s relaxed manner.

And in the courtyard of Pacorus’ quarters, Tarquinius studied the stars filling the heavens. Try as he might, the haruspex could not see past the battle that lay ahead.

As at Carrhae, the slaughter would be immense. Too many men would die to allow the paths of three single individuals to be discerned on their own. But where were the visions that had showed the possibility of returning to Rome? Had Olenus, his mentor, been wrong?

Tarquinius too was filled with unease.

As Romulus and Brennus emerged from the confining sides of the narrow pass and the men in front began to descend, they were granted a view of the land that awaited them. Eleven days had passed and the Forgotten Legion was about to complete its traversal of the mountains to the south of its fort. With Pacorus’ expert knowledge of the area, the legionaries had marched safely through a narrow defile, well below the snowline.

‘Great visibility,’ said the Gaul, pointing due east. ‘I’d say fifty miles at least.’

It was hard to disagree. With a cloudless sky overhead, the crystal-pure air allowed them to see every tiny detail below them. Rivers thundered down from the peaks to divide the landscape into huge, irregular portions. This was more fertile land than that to the north. Small villages were dotted throughout, their patchwork fields spread unevenly around the houses. On the foothills that ran down from the mountains were thick clumps of trees. Unlike the Romans, the Parthians and Bactrians did not build roads, but plenty of well-worn tracks joined the areas of human inhabitation. It was not dissimilar to parts of southern Italy.

Pleased mutters rose from the other soldiers: there was no sign of a huge host.

Romulus sighed. He did not know which was worse – the expectation of doom, or the actuality of it.

Brennus threw a comforting arm around his shoulders. ‘We’re all still alive,’ he said. ‘Breathe the air. Enjoy the view. You might as well.’

He managed a small smile.

From the following dawn, they advanced steadily, covering a good fifteen miles before dark. The next day it was twenty, and the day after that, a few more. No one knew exactly where they were going, but the rumour was that their destination was the River Hydaspes.

This was proved correct when, after nearly a week’s march, an enormous watercourse eventually halted the Forgotten Legion’s progress. Running almost directly north-south, it was at least a quarter of a mile wide. A less imposing barrier than the mountains, the river still acted as a formidable natural border.