'Close ranks! Prepare for attack!'
The men at the front needed no prompting. Shields slammed together while the soldiers behind held theirs angled overhead. There was nothing else to do. Legionary scuta could resist normal missiles, but as every man knew only too well, the Parthian bows were different.
Clouds of dust rose from the horses, filling the atmosphere with a fine choking powder. With the Romans in a continuous line, the archers were unable to ride around each cohort as before. Now they would have to ride along the enemy's front and far fewer could attack at any one time.
This provided Crassus' legions with only a shade more respite. A wave of riders swept in, releasing hundreds of shafts from fifty paces. The Roman officers did not order volleys of javelins. There was no point. As the Parthian assault withdrew, it was immediately replaced by another. Storms of arrows rained upon on the beleaguered army, piercing wood, metal and flesh without distinction.
Screams of pain rose up as the barbed tips penetrated scuta, taking out eyes and pinning feet to the sand. And every soldier that fell created a hole in the shield wall. Into these gaps came scores more missiles, the Parthians using every opportunity to decimate their foes. The Romans cowered under their shields with gritted teeth, praying.
Several of Bassius' mercenaries fell wounded in the prolonged onslaught. Following the centurion's lead, the others snapped the shafts off and pulled them out when they could. Men roared in agony as blood poured from their wounds. The air was filled with the moans, galloping hooves and the hiss of feathered shafts: a terrifying cacophony.
Romulus had grown used to the shrieking, but the number of combatants was far greater than he could have ever imagined. This was death on a grand scale, the sheer magnitude of slaughter impossible to comprehend. Cannae must have been something like this, he thought. A battle that the Republic had lost.
The attacks lasted as long as the enemy had arrows. Whenever the Parthians had exhausted their supply, they simply rode back to the camel train for more. There were enough archers to ensure that any breaks were few and far between. At various stages, the frustrated centurions ordered javelins be thrown, but the horsemen were rarely close enough. Hundreds of pila flew through the air to land on the sand, wasted and useless.
After hours of this endless cycle, Roman morale was falling fast. In the ranks of the Sixth alone, nearly a thousand men had been killed. Hundreds more lay injured on the baking hot sand. The air was now thick with dread and the officers were finding it increasingly difficult to keep their units in position.
On the left wing, the Iberian cavalry had fled, unwilling to suffer the same fate as the Gauls. With no sign of Ariamnes and his Nabataeans, the Romans retained no horsemen at all. The rest of Crassus' army had been battered to a pulp, left unable to respond in any way.
Cohort after cohort stood reeling under the onslaught. Parched. Exhausted. Wavering. And about to run.
But instead of another attack, the drums and bells began to sound. While the noise rose in an unearthly crescendo, the horse archers pulled back. Unsure what was happening, the uninjured Roman soldiers waited, their nerves wire-taut. Thanks to the dust cloud that had taken up a permanent place between the two forces, the Parthian army was invisible to them.
For what seemed an eternity, nothing happened.
Then the instruments fell abruptly silent. Surena was a shrewd judge of men and it was time for the hammer blow.
Beneath Romulus' feet the sand began to tremble. Still nothing could be discerned before them.
Then he knew.
'Cataphracts!'
The senior centurion stared at Romulus blankly.
'A charge by heavy cavalry, sir!'
Bassius turned to Sido and swore. 'They will smash us apart! Everyone still with pila to the front.'
The other centurion nodded jerkily. He had seen the cataphracts and could well imagine their capability.
'All men with javelins move forward! Hurry!'
Brennus pushed his way through, keen to get to grips with the enemy. He was sure now that his journey was being watched over by the gods themselves. Therefore there was a purpose to it — to all he had sacrificed. Now it was time to fight.
Having thrown their pila already, Romulus and Tarquinius stayed put.
'Other ranks, close up,' ordered Bassius. 'Use your spears to stab the horses' bellies. Gut them! Take their fucking eyes out! Rip the riders off!'
'Stand fast!' Sido raised a bloody gladius in the air. 'For Rome!'
The soldiers managed a ragged cheer and hurriedly formed up. Romulus and Tarquinius found themselves in the second rank, a few paces behind Brennus. The Gaul had elbowed his way to stand near the two centurions.
The ground shook from the drumming of hooves and a low thunder filled the air. Bassius had just enough time to shout, 'Shields up! Pila ready!' before the Parthians emerged from the concealing gloom. Riding in a wedge formation, the desert horsemen were already at full gallop. In response to a shouted order, their heavy lances lowered as one. The centurions had no chance to order a volley of javelins. With devastating force, a thousand heavy cavalry punched into the Roman lines. Sido and those at the front were smashed aside or trampled underfoot while the men behind received a lance in the chest.
Romulus watched in horror as the unstoppable tide poured through the cohort's centre, driving all before it. He struggled to reach the fighting, but the press was so great there was little to do but watch. Here and there a soldier stabbed a horse in the eye with a pilum. The mounts reared up in pain, their hooves dashing out the brains of those nearby. Cataphracts clutched frantically at the reins as vengeful legionaries pulled them from the saddle. There was no mercy. Swords ripped into Parthian throats; blood gushed on the sand.
He glimpsed Brennus pulling a mailed warrior down with brute force and stabbing him in the face. Bassius and a few others managed to hamstring half a dozen horses, dispatching the riders with ease. And somehow Tarquinius had wormed his way through the tightly packed ranks to the fighting. Romulus had seen his friend use the battleaxe on several occasions, but never tired of watching the Etruscan's skill and grace. The sinewy figure spun and chopped, wielding the massive weapon with ease. Its curved iron heads flashed to and fro and Parthians screamed as hands and arms were severed. Horses went down thrashing, their back legs slashed to pieces.
Tarquinius was not merely a soothsayer.
But for the most part the Parthian attack had been successful. As the cataphracts smashed through the rear ranks, a great hole was left gaping in the Sixth Legion. Hundreds of casualties sprawled on the bloody sand, howling in agony. Lances and bent pila jutted from the dead of both sides. In the section where Romulus and his friends were positioned, all the regular centurions had been killed, leaving the soldiers leaderless and confused.
The sheer power of the charge had destroyed more than the Roman line. It was the final straw for legionaries whose confidence had been steadily eroded all day. Many were veterans who had fought against every enemy the Republic could find and tasted victory in many countries. But Crassus had presented them with a foe they could not fight on equal terms: horse archers who killed from a distance; heavy cavalry which trampled with impunity.
The cataphracts turned on the open ground behind the army. Cries of terror greeted them as they pounded the sand back towards the Romans. Driving through another part of the Sixth, the mailed riders hacked scores more infantry to pieces with their longswords, then disappeared into the clouds of dust.