Now the brief cool of dawn had faded away, leaving soldiers at the sun's mercy. The yellow orb quickly climbed to fill the entire sky, blasting the ground below. Irrigated fields with their sheltering palm trees grew sparser, then died away completely. Five miles from the Euphrates, all signs of habitation had disappeared. Soon afterwards, the narrow road the legions were following led off between lines of undulating dunes and came to an abrupt end.
The view that awaited them was shocking.
As far as the eye could see, a vast emptiness stretched. It was a burning wasteland and a great sigh of anticipation escaped men's throats. Spirits fell and the cohort's momentum was suddenly stalled by deep sand which was far harder to march in.
'Crassus has lost his mind!' said Brennus furiously. 'Nobody can survive out there.'
'Quite similar to Hades,' commented Tarquinius. 'But if the Greeks did it, we can.'
'Not a living thing. Just sand.' At the limits of Romulus' vision danced a shimmering haze. It was like nothing he had ever seen before.
'What are you waiting for? Sluggards!' screamed Bassius, the phalerae on his chest clinking. 'Forward march! Now!'
The Roman army's formidable discipline prevailed. With a deep intake of breath, the mercenaries entered the desert's oven-like heat. It was not long before the soldiers' feet were burning through the soles of their caligae. Chain mail shirts grew uncomfortably hot to touch. Exposed skin began to burn. Despite strict orders to conserve water, men began taking surreptitious gulps from their gourds.
Romulus was about to do the same when Tarquinius stopped him.
'Save it. The next waterhole is more than a day's march.'
'I'm parched,' he protested.
'The man's right,' added Brennus. 'Stay thirsty.'
Without breaking step, Tarquinius stooped to the ground and picked up three smooth pebbles, passing one to each of them before popping the last in his own mouth. 'Put it under your tongue.'
Brennus raised his eyebrows. 'Have you gone mad?'
'Do as I say,' Tarquinius said with an enigmatic smile.
Both men obeyed and were amazed when moisture instantly developed in their mouths.
'See?' Tarquinius chuckled. 'Stick with me and you'll go far!'
Silently Brennus clapped the Etruscan on the shoulder. He was glad that the soothsayer was full of surprises.
Reassured by his friends' guidance, Romulus strode ahead, full of youthful enthusiasm. The young soldier felt even surer that with Brennus and Tarquinius nearby, little could go wrong. Seleucia would fall in a matter of days, making them rich. Then all he needed was proof of his innocence so he could return to Rome. Quite how that would be achieved was unclear, but he had unfinished business there. Rescuing his mother and Fabiola. Finding Julia. Killing Gemellus.
Starting a slave rebellion.
They had been marching for much of the afternoon when they were alerted by a cry from the front.
'Enemy ahead!'
All eyes turned to the southeast.
Romulus peered at the confusion of sand and rocks but could see nothing.
Brennus squinted into the blinding light. 'There!' he pointed. 'To the right of the lead cavalrymen. Must be a mile away.'
Beyond the Gaul's outstretched hand, Romulus could just make out a faint puff of smoke curling up into the haze.
Slowly the dust cloud grew larger until it was visible to all. The thunder of horses' hooves carried through the hot, still air. As soon as the senior officers had been notified, the halt was sounded. With sighs of relief, men grounded javelins and shields, waiting for orders.
'Stay put. Drink some water, but not too much!' Bassius paced up and down the cohort, encouraging his soldiers. 'The cavalry will check it out before we have to worry.'
'Nowhere to go anyway, sir. Unless it's the next sand dune?'
The anonymous comment raised a laugh from those who could hear.
'Silence in the ranks!' roared Bassius.
Responding to further trumpet calls, the cavalry nearest the enemy took off. Their fair skin, flowing hair and moustaches clearly marked them as Gauls. Some wore chain mail but many had no armour, relying instead on their speed and agility. They were not gone for long, most returning to their position while a decurion rode back to the centre of the column to report.
'What did you see?' bellowed Brennus as the officer cantered by.
Bassius glared at the indiscipline but remained silent, keen as anyone else to know what was happening.
'A few hundred Parthians,' replied the decurion dismissively.
Murmurs of excitement rippled through the cohort.
The news did not seem to alarm Crassus. Moments later, the advance sounded once more. Romulus found himself picking up pace as the marching speed perceptibly increased. Sight of the enemy had reduced the daunting prospect of desert wastes.
The group of horsemen soon came into sight, riding to within a quarter of a mile of the Roman vanguard. The Parthians pulled across their path, sitting astride short, agile ponies. Each man wore a light jerkin, decorated trousers covered by chaps and a conical leather hat. Large case-like quivers hung from the left sides of their belts. All were carrying deeply curved composite bows, similar to those of the Nabataeans.
'They're not even wearing armour,' said Brennus contemptuously.
It was hard to feel scared. If these horse archers were all the Parthians had to offer, then the huge Roman army had little to fear.
'They're just skirmishers,' observed Tarquinius. 'Here to soften us up for the cataphracts.'
It sounded ominous.
'Those bows are made with layers of wood, horn and sinew. Gives them twice the power of any other.'
Brennus' eyes narrowed. If he could send an arrow from a Gaulish bow through chain mail, what would the Parthian weapons be able to do? A shiver ran down his spine at the thought.
Tarquinius was about to continue, but Bassius came striding past, vine cane at the ready.
The Parthians sat motionless until Publius responded to the challenge. He ordered the charge. But his men had only ridden a hundred paces before the enemy turned tail and galloped away, leaving the heavier horses floundering behind. When the Gauls reined in to conserve their mounts' energy, the archers began taunting them.
Watching carefully, Publius held his men in check.
Suddenly a wave of arrows snaked into the air. Falling in a deadly shower, it knocked many Gaulish riders to the sand. Enraged, three troops immediately broke off and charged straight at the Parthians.
'Where 's their discipline? The fools think they can ride them down,' said Tarquinius. 'The Parthians are not infantry!'
Fascinated, Romulus watched as the irregular cavalry thundered towards the archers, trailing clouds of dust. Used to smashing aside opposition with ease, the Gauls roared and whooped. He could imagine how terrifying such an attack would be for foot soldiers. Lacking mounted units of its own, the Republic relied on conquered tribes like Gauls and Iberians to provide its horsemen. Carrying lances or javelins and long slashing swords, the cavalry served as a battering ram to break up enemy formations.
The ill-disciplined charge was precisely what the Parthians desired. As the Gauls closed in, they trotted off, turning gracefully in the saddle to fire at their pursuers. Swarms of arrows filled the air and Romulus gaped in amazement at their accuracy. Within moments, only thirty Gauls of the ninety who had charged were left alive. Corpses littered the ground, staining it red with blood. Dozens of riderless horses galloped about aimlessly, many bucking and kicking in pain from their wounds. The survivors reined in and fled, losing more men as they did. Sounding the recall, Publius retreated to the main column, leaving the Parthians victorious.