A mighty shout rose to the sky drowning even the pounding of the war drum; Vespasian did not need to look to know that the Parthian cavalry had collided with Mannius’ cohort. It was now just a matter of time.
Vespasian led his scratch incendiary unit at a lung-burning pace back across the siege lines directly to where the uneven cataphract-versus-infantry battle abutted them. He scrambled up the edge of the final earthwork, his arms cradling the Naphtha pots, struggling for balance and dislodging loose soil that tumbled down into Magnus’ face behind him. His head cleared the top of the defence and he looked along the length of Mannius’ cohort’s line, all the way to the city walls, a bowshot distant. And it was ragged, beset by armoured killers mounted upon beasts almost impervious to the weapons being wielded against them. With their horses pressing their huge bulk against the cohort’s front rank, pushing them down and back with cracked skulls and broken limbs, the Parthian troopers used their far-reaching kontoi to stab razor-edged points down into the faces of desperate auxiliaries in the second and third ranks, preventing them from using their weight in support of their comrades before them. Screams rent the air as eyes were pierced and throats were gouged; dying men dispersed sprays and mists of blood with their final explosive breaths as the juggernaut of cataphract cavalry pushed into the Roman infantry with the ease of a voyage-weary sailor penetrating a dockside whore. Javelins, swords and knives could not halt them, but Vespasian held in his hands the only weapon that would: fire.
Kneeling, he set down one of his pots. ‘Hormus! Bring the brands.’
The slave clambered up the bank with three thick sticks with red-glowing ends.
Without thinking of the dangers or whether he was doing it correctly, Vespasian proffered the Naphtha. ‘Light it!’
Hormus touched the glowing end of the brand to the trailing rag; it smouldered for a moment and then flashed alight as if impregnated by some accelerant, shocking Vespasian. Panicked by the rapidity of the fuse’s burning, Vespasian leapt to his feet and brought the pot, two-handed, behind his head, bending his back and legs, and then levered it forward with the pressure of his whole body unfurling behind it. The pot soared along the Parthian line to crash down onto the unarmoured rump of a front rank horse, twenty paces away, splintering into jagged shards and spilling a viscous brown liquid over the beasts and troopers close by; but it was virtually unnoticed in the chaos of battle as it did no more than that.
Vespasian dropped back to his knees. ‘Shit! Nothing happened.’
Magnus stuck his fingers into the wax seal of one of his pots, breaking it. ‘That should help. Hormus!’
The slave had more life in his eyes than Vespasian had ever seen before; he touched the glowing brand to the rag and, as it flared up, Magnus jumped to his feet with his right arm stretched behind him and his left arm crooked in front, balancing, and, with one fluid motion, he hurled the pot, with as straight an arm as an onager’s, so that it outdistanced Vespasian’s throw by a few paces. It ignited an instant before it crashed onto the helm of a second rank rider, immediately engulfing him and his mount in flame and splattering his comrades close by with sticky, burning slops. With a sudden detonation, the contents of Vespasian’s pot exploded with the deathly fury of the fire god. The agonised, terrified shrieks of both man and beast drowned the clash of weaponry and for a few moments all conflict ceased as the combatants watched the immolating horses buck and rear, dislodging writhing riders as both were roasted alive within the metal ovens that were supposed to make them almost invulnerable.
‘Centurion!’ Vespasian shouted above the continuous screams. ‘Now that you’ve seen how these things work, take your men along the rear of our line and throw as many pots at those armoured bastards as you’ve got.’
With a grin the veteran saluted and, grabbing a couple of the brands from Hormus, loped off with his men following to cause burning mayhem. Magnus lit his second pot and tossed it at the cataphracts nearest the earthworks who had resumed beating down the lessening resistance of the overwhelmed auxiliaries. As they too were engulfed by the fire god’s wrath, howling their pain to their own uncaring deities, the Parthians closest to the two conflagrations began to disengage, unwilling to risk sharing in the skin-shrivelling, fat-sizzling, baking deaths that were being meted out seemingly from the heavens.
And then clumps of flames burst forth from the Parthian line, one by one, at irregular intervals, marking the progress of the centurion and his men along the rear of the auxiliaries. With the exception of one poorly aimed shot that was bringing a searing death to a dozen or so screaming Romans, the centurion’s men had managed to lob their deadly incendiary missiles over the infantry to cause their enemy’s cohesion to fracture in many places as the animal instinct to run from fire became the cataphracts’ overriding motivation.
And those that could turned and fled. Some with patches of sticky fire clinging to them, adding urgency to their retreat; others with armour heated by close contact with blazing comrades and steeds; and then others, the majority, untouched by fire but not untainted by the fear of it. Within a few heartbeats the surviving cataphracts had turned their tails and were heading back towards the horse archers who, in turn, withdrew to facilitate their comrades’ withdrawal.
But it was not the fleet and nimble flight of the fresh and unencumbered; quite the reverse. Despite their powerful fear, the great beasts were unable to generate much speed, having been armoured for a few hours now, plus having charged and fought. All they could muster was a lumbering walk that left their exposed rumps open to the unthrown javelins of the jeering Romans; and, as Mannius realised the opportunity was there, they were used without pity. To the bellowed, succinct commands of their centurions each century hurled their primary weapons at the slowly retreating cavalry, adding to their panic as their hind-quarters were riddled with deep wounds, causing many to collapse from stress and over-exertion.
Mannius, however, was a commander of experience and he kept a tight hold on his men, forbidding them to follow up their retreating foe and, instead, held them steady as Fregallanus’ cohort began to follow the baggage train across the Tigris. The extreme right of his cohort abutting the city walls had started to peel back, century by century, to follow their comrades heading for the bridge.
Vespasian, Magnus and Hormus stood on the top of the earthen embankment surveying the field in astonishment, now littered with heaps of flaming metal that flared and sizzled as the bodies encased within them gave up their fat; smears of dark smoke, stinking of burnt man- and horse-flesh, drifted between the line of auxiliaries and the beaten, retreating Parthians. The cries of the wounded were surprisingly few and mainly confined to the Roman side, for neither cavalryman nor his mount could survive the broiling temperatures of the weapon given to man by the god of fire, Apam Napat.
‘That’s how to do eastern bastards who like to cover themselves with cooking pots,’ Magnus observed, his blood-encrusted face now blackened with the smoke’s residue. ‘I’d say they were well done, if you take my meaning?’
Vespasian did but was in no mood for levity. ‘You seemed to know something about that stuff.’
‘I might have come across it in Rome,’ Magnus muttered evasively. ‘You wouldn’t want to know the details.’
‘I’m sure. Come on, we’ve still got work to do.’ He turned and slid back down the slope as the centurion and his eight lads returned from their inflammatory rampage. Behind them Fregallanus’ cohort had begun to cross the bridge. ‘That was good work, centurion; now follow me.’ He scrambled out of the other side of the trench and made his way as fast as possible back to the artillery; there were still a couple of dozen Naphtha pots piled next to the onager. ‘Get these onto the wagon,’ he ordered, pointing at Hormus’ vehicle, which remained where Magnus had abandoned it.