Slowly the vast numbers of the enemy began to tell and the First Cohort was forced to give ground, step by step. Men were falling, caught by spear thrusts through gaps in the shield wall, or sometimes overwhelmed when one of the Nubians managed to wrench a shield aside long enough for one of his fellows to strike a blow at the legionary behind. Though the losses of the Nubians were far greater, Cato could see that the four-deep line with which the cohort had begun the battle was reduced to three men in most places. The bowed-out formation was steadily flattened, and then began to curve inwards as the more solid formations on either side of the First Cohort still managed to hold their ground. Out on the wings the cavalry cohorts were fighting off a second, half-hearted attack by the enemy horsemen. The battle was going to plan, Cato realised, and he promised a generous offering to Fortuna if luck continued to favour the side of Rome, as the battle entered the decisive phase. It all depended on Macro and the First Cohort, holding their formation as they gradually fell back.
'Sir?'
Cato turned to see an optio standing beside his horse. 'Yes?'
'Message from the Prefect Scyllus, sir. He begs to report that his archers are running out of arrows.'
'Very well. Tell the prefect to save what he has left and form his men up behind the reserves.'
'Yes, sir.' The optio saluted and turned to run back towards his unit.
As the rain of arrows stopped, the enemy drums beat with renewed energy and the horns blared out to offer encouragement to the Nubians. The pressure continued and the Roman centre was driven inwards as the enemy pushed forward, heedless of their own dead strewn across the battlefield beneath their feet. Prince Talmis's body of heavy infantry had pushed their way through the throng and now engaged the tiring men of the First Cohort. Well trained and equipped, they were able to fight the Romans on a more equal footing and more of Macro's men were cut down. The line was growing perilously thin as Cato watched. Yet he dare not give the order to spring the trap before he was certain the moment was right.
'Sir!' Junius shouted, thrusting his arm out. 'They're going to break through!'
Cato turned and saw the threat at once. A short distance to the right of Macro's centre a single rank of legionaries was struggling to hold back the enemy. They thrust their shields forward and their iron-nail shod boots scrabbled in the sand and grit as they desperately tried to stand their ground. But it was like holding back a flood with a line of sticks. One of the men slipped and went down on his knee. At once two Nubians thrust his shield back, knocking the legionary flat. He was run through with a spear even before he could prop himself back up on an elbow. More men pressed through the gap and turned on the Romans on either side.
'Shit,' Cato muttered. The crisis of the battle had been reached. A rising cheer of triumph swept through the nearest of the Nubians as they scented victory. There was one chance left, Cato realised, wheeling his horse round to face the men of the reserve cohort. The legionaries stood to, shields resting on the ground, javelins held to the side.
'The fate of the army is in your hands!' Cato called out to them as he drew his sword. 'You must save your comrades of the First Cohort and seal the gap in our line! For the Jackals!'
The centurions led their men in a throaty cheer that was unmistakably half-hearted. Cato could not afford the reserve to fail, and with the briefest of hesitations he swung his leg over the saddle and dropped to the ground. 'Follow me!'
Cato strode towards the Nubians pushing forward through the First Cohort. The senior centurion of the reserves gave the order to advance at the trot and the legionaries came on, grim-faced, javelin points held high as they rumbled across the parched ground. Cato was still twenty paces ahead of them when he reached the gap. Several of the Nubians had stopped in their tracks as they saw the fresh formation closing on them. Choosing the nearest of them, a man with wild hair and armed with a club, Cato broke into a dead run, hunched forward and sword held out to the side, ready to strike. His left shoulder burned with pain from the blow he had received at the temple and Cato gritted his teeth as he swerved to avoid the clumsy blow of his foe, and thrust out his left palm into the man's face, snapping his head back and knocking him to the ground. He didn't pause to finish the man but turned aside to the next, a dark-robed Arab brandishing a spear. The point came up, stabbing at Cato's throat. He parried the shaft aside with his sword and then grabbed it with his spare hand. The Arab growled a curse as he tried to snatch it back. Cato thrust his sword high into the man's arm, and again, until the grip loosened. As they struggled, the rest of the reserve cohort came charging up, the front rank lowering the javelin tips and thrusting out at the enemy who had managed to spill through the gap in the First Cohort's line. They pressed past Cato on both sides, one of them stopping to slam his shield into the Arab and send him sprawling. A quick javelin thrust killed the man and the legionary ran on as Cato nodded his thanks.
The sudden arrival of four hundred men sealed the break in the line and steadied the hard-pressed legionaries of the First Cohort. Cato drew back from the fighting and returned to his horse. Junius stared at him as if Cato were mad for leading the charge, but he ignored the tribune and turned to survey the battlefield. The bulk of Prince Talmis's army had been drawn into the centre of the Roman line, as Cato had hoped it would be, making for where the Romans seemed weakest. On the flanks the main weight of the legion still stood in column, scarcely touched by the enemy missiles. The moment had come, Cato knew. He must attempt to close the trap now, while the centre of his line was still intact.
He nodded to Junius. 'Give the order.'
The tribune hesitated. 'Sir, I-'
'Give the order!'
The soldiers carrying the bucinas heard the command and did not wait for it to be relayed to them. They pursed their lips and raised their mouthpieces and blew. Three strident notes blasted out across the battlefield. The signal was repeated and before the last note died away the two columns of legionaries began to advance, fighting their way forward along the sides of the Nubian horde, out beyond the buckling line of the Roman units holding the centre. Beyond them the cavalry cohorts also advanced, in echelon as they covered the flanks of the Roman army.
At first the Nubians appeared to be unconcerned by the columns of legionaries extending around the edge of the host. Those in the centre were still convinced that victory was in their grasp; they fought like lions to break through the Roman line once again. Cato saw a silken banner rippling from side to side above the centre of the Nubian ranks and he realised that Prince Talmis had come forward in person to urge his troops to shatter the slender force that still held them back.
The flanking cohorts tramped forward until the last century had linked up with the main battle line. Then they stopped. A command was passed down the line and each cohort turned inward to face the sides of the massed warriors of the Nubian army. Another command echoed along each of the extended wings and the legionaries formed their shields into an unbroken wall. Then they advanced, pressing the enemy back before them and cutting down all those who came within reach of their short swords.
While the legionaries closed the trap, the auxiliary cavalry charged forward, cheering as loudly as they could as they made for the enemy horsemen still formed up some distance behind their infantry. If the enemy's nerve held, no amount of noise and raw courage would save the outnumbered auxiliaries from eventual defeat. Cato had calculated that their sacrifice would buy enough time for the rest of the Nubian army to be defeated. However, as he watched, the Nubian horsemen and the camel riders began to break away from their formations, individually at first, then in small groups, streaming away across the landscape to the south.