Some weeks after the encounter with Isaac, the flat, arid terrain had been replaced by a range of hills covered in scrubby bushes and trees. Marching through them, the legionaries entered the green plains of Margiana. To their delight, there were frequent watercourses, fed from the mountains visible on all sides. This was inhabitable land, the polar opposite of the wastes left behind. It reminded Romulus of the countryside he had seen while journeying from Rome to Brundisium.

Water bottles were now full every day, the game plentiful and temperatures acceptable. Each night the men's bellies were stuffed with meat. The Parthian guards relaxed. Life had become more enjoyable. Even the cloud of vultures that had followed them all the way from Seleucia thinned out and disappeared.

The attention of the gods had been drawn away from the Forgotten Legion.

'You were right!' Felix stared at the verdant scenery with delight. 'Rivers. Fertile soil. There are farms here.'

'Told you,' answered Brennus with a smile. 'Trust Tarquinius.'

Felix shook his head in amazement.

Cultivated areas and clusters of low mud huts were common. Several villages had been spotted, but Pacorus did not enter them. He was deliberately keeping a low profile. There had been only one stop, lasting several days, near a small Hellenic-looking town surrounded by a protective wall.

Tarquinius and the Parthian had gone in alone, and had placed an order with every blacksmith to be found. Margianian iron was renowned in Parthia for its quality and was used to forge the cataphracts' armour. On the third afternoon they had returned, their mules laden with thousands of long spears. The weapons had immediately been issued to half the men and training had begun the next morning. New manoeuvres were taught, soldiers grumbling as they were organised into strange formations.

Nobody was told why. But Brennus and Romulus suspected. As usual, the Etruscan would not say.

Wishing to reach the border quickly, Pacorus led the Forgotten Legion in a northeasterly direction across Margiana until they had reached rolling grassland. Filled with abundant wildlife, the virgin green landscape stretched as far as the eye could see. Antelope were sighted daily, allowing hunting parties to provide the army with even more fresh meat. To vary their diet, Romulus and Brennus caught fish from streams.

Occasionally they saw encampments of large, round tents with pointed roofs. Herds of horses, sheep and goats spread out around the settlements, grazing the lush pasture. Men and boys on horseback kept watch over the animals. Just as Tarquinius had described, the tribesmen were squat people with yellow skin, black hair and slanted eyes.

'Outlandish-looking folk,' commented Brennus as they passed a sizeable group of tents. 'But they seem peaceful enough.'

The riders nearby reined in and watched impassively as the column marched past. Their rough cloth jerkins and trousers were covered in autumn mud and they carried only the ubiquitous bows and hunting knives. Few legionaries bothered to look. The locals were of no consequence.

Tarquinius nodded. 'They are practically settled. But the nomadic Sogdians who raid this area look very similar.'

Brennus stared curiously at the riders' flat noses and high cheekbones. 'I'll wager they've not set eyes on too many of us.'

'Or seen a man your size!' said Romulus.

They both laughed.

'Their ancestors would have.' Tarquinius always had more information. 'Alexander founded the city of Antiochia not far from here and it is still the capital of Margiana. Most of the trade from the east passes through its gates.'

'Local legends tell of mighty soldiers with pale skin and blond hair who crushed all before them.' Pacorus had overheard the comment as he rode by.

Those who could understand some Parthian looked round with interest.

'Greeks!' said Romulus, imagining the army that had marched so far from home, nearly three centuries before. As ever, the thought fired his imagination.

It was old news to Tarquinius.

'This area has only been under our control for a generation,' the Parthian officer continued. 'The inhabitants don't like us and rebellions are common. And tribes from the north think the grasslands are theirs to graze, the towns free to plunder. The Forgotten Legion's job is to teach them different.'

'Plenty of fighting then, sir?' There was a glint in Brennus' eye.

'Quite likely,' revealed Pacorus. 'And very soon.'

Romulus felt a surge of pride to hear the name being used and from their reactions, other men felt the same way too. They were still Roman soldiers. The eagle still led from the front. Holding on to their identity had been a crucial part of survival. Without it they were nothing. Prisoners with no future, banished to the ends of the earth.

'We are needed at the border,' Tarquinius said unexpectedly.

Pacorus' mouth opened. 'Messengers brought word this morning,' he admitted gloomily. 'Been a raid by Sogdian tribesmen. Thousands of the bastards. They've hit several towns north of the capital. Burned them to the ground.'

'The men are ready, sir.' The Etruscan indicated the silk on every shield, the long spears. 'If I could have a word . . .'

'Why?' asked the Parthian suspiciously.

'Got a surprise for the enemy.'

Pacorus beckoned.

Everyone watched with bated breath as the Etruscan broke ranks to confer with their commanding officer. Tarquinius spoke urgently, gesturing with his hands while the other listened. The conversation did not last long.

Pacorus barked an order at the trumpeters, who immediately signalled the legion with silk covers to halt.

'This plan had better work, soothsayer.'

'It will,' said Tarquinius calmly.

Moments later, the Parthian second-in-command led away the other half of the legion to the west, towards Antiochia. When the men with Tarquinius realised their comrades were not also heading for battle, insults filled the air. Soldiers marching away responded with laughs and jeers.

'Where are they going?' asked Felix.

'To defend the capital.' The Etruscan smiled. 'And set up camp. There 'll be no ditches to dig when we return.'

'From where?' said Felix dubiously.

'The river forming the border.'

Questions flew thick and fast as men clamoured to know more.

But Tarquinius would not answer and stepped back into line, fixing his eyes on the horizon.

Trumpets blared stridently and drums pounded. Officers listened, then roared the commands. The soldiers moved off, thousands of iron-shod sandals grinding the grass flat.

'Sons of whores have probably escaped.' Pacorus stared into the haze. 'We got here too late.'

Long grass extended south to the horizon. In the distance, a range of low hills ran from left to right. Clumps of trees provided the only variation in the panorama. Birds sang overhead, competing with the hum of countless insects. The air was still, carrying every sound. Some distance away, a herd of antelope nervously watched the soldiers. It did not take long for them to move away, grazing as they went. Bright sunshine lit up the fertile land, but there was no sign of human inhabitants. This was too near Sogdia.

It was fierce tribesmen from the bare steppes that the Forgotten Legion was waiting for.

'There's been no sign of their passage,' Tarquinius reassured him.

Behind the legion's massed ranks stood the Parthian guards, the trumpeters and drummers. At their backs ran a broad, swiftly moving river. Muddy tracks near their position led down the bank into the water, good sign of a crossing point. The hoof prints mostly led out, into Margiana. It was clear that few horses had passed north in recent days.

The Parthian glanced at the ford yet again.

'You said yourself it would take them three days to get here.'