A mile out from the colony, they saw the first abomination. Shambling along the road, the ragged, rotting lump of flesh that had once been a man turned slowly towards the Chimeras quickly bearing down on it. Mindlessly, it started limping towards them, heedless of the harsh fate that awaited it, before it was obliterated by a chimera's multi-laser, the harsh beams of energy tearing through its sickly form and tearing it in half, the still twitching halves crushed beneath the hard treads of the transport.
From behind the viewport, alongside the driver, Squadleader Jacen frowned. He didn't like the way these things looked, the way they acted-anything about them, but the worst part them was the stench- the unrelenting smell that you could feel fifty meters out, and smell a thirty. One could practically feel the chaos coming off of the abominations.
He sighed, leaning back in the hard bucket seat, the driver's harness chafing his shoulders. It had been a long campaign on this backwater world, finding and eradicating Nurgle's cult. He honestly wasn't sure why exactly they had decided to come to this world in the first place- wouldn't a jungle planet be more to their liking, with all the possible life to corrupt, unlike this volcanic backwater, with all its stone and hot vents?
Not that he was complaining about the cult not picking a jungle world- he didn't want to think about fighting on one of those. The cities here were bad enough, and it would only be worse if the plants were trying to kill him.
The city grew more visible as they approached, and he started to feel the emanating stench before he smelled it, the air growing thick with the smell of rotting flesh. Everybody had gotten used to it by this point, though, so he didn't hear any retching from the gunners.
The chimeras ahead sent out the occasional blast to tear apart an abomination, the blasts growing more frequent even as they drew closer to the city and the abominations started to appear in clumps, the vehicles in their formation blasting away as the roar of the engines echoed across the landscape.
And then they were there.
Pulling to a halt, the driver cut the engine, the roar of the power plant slowly dying down as black exhaust belched out the back of the machine. Stepping back into the gunnery bay, Jacen cursed at the stench of the city, tightening his respirator, looking over his men as he did so.
Orde and Gran, the loading crew, looked over at him as he stepped up into the gun bay, the main cannon towering over him. Tere, the spotter, looked over and waved. Stepping up onto the side of the Basilisk, Jacen joined him in looking out over the plains at the city.
Past the thin line of freshly deployed infantry a few hundred meters ahead, beyond the rocky, dusty plain dotted with the occasional abomination, lay the smoking ruins of the city, Renan.
The smokestacks and trusses of the manufactories stood smoking, ruined, and covered with growths in the most repulsive colors imaginable to man. Looking through a field glass, the streets seemed to swarm with movement. Profane symbols and runes covered the sides of buildings all over the city.
The city of Renan had fallen only a week ago, and while it would normally have been acceptable to blast it to pieces from orbit, the large geothermal reserves it sat on made such a decision inadvisable, as was the case with several of the cities they had seen beforehand. So, in an attempt to stop the cult from spreading any further, they, the Nerian 6th, had been sent to perform exterminatus.
It was their fifth city to date, and the biggest one yet. Even as the men of the sixth prepared artillery for firing, checked lasgun charges one last time, or readied tank cannons, they could feel the oppressive aura of pure, unadulterated chaos emanating from the city.
As countless tanks, artillery guns, and men went about their business, a strong, simple voice crackled through the vox- "This is Battalion Commander Sher Reman. Commence Exterminatus."
And it began.
Over a two hundred basilisk guns opened fire all at once in a massive concussion that shook the ground for a klick around as high explosive, incendiary shells sped towards their targets in the city.
Even before the shots met their targets, the gun crews started to reload, spotters shouting firing coordinates over the din of artillery fire as the guns began to pound upon the city. Tall trails of smoke rose from gaping, burning holes in the city, joining the smoke from the city beforehand to cloud the skies above with thick, hazy smoke.
Jacen allowed a grim smile to creep onto his face at what he saw happening in from of him, saw the chaos plague-laden city burning before his eyes. Adjusting his respirator, he realigned the gun to the spotter's coordinates, and keyed the firing rune, the massive blast from the muzzle splitting the air as the massive, earthshaking shell was launched into the sky, to land on the diseased city but a few seconds later.
Amidst all the rumble of the guns and the occasional snap-crack of lasgun fire as a guardsman put down a wandering abomination, Jacen barely felt the steady thud, passing it off as a rhythm in the guns. But then it grew stronger, more noticeable.
It was the sound of pounding feet. A lot of feet.
Scrambling up to the side, Jacen grabbed Tere's field glasses and focused in on the city, scanning the streets for movement, until he spotted the column marching out of the city.
It was a huge mass of abominations and cultists, all starting out from the city at a run- straight towards the encircling ring surrounding the city. Marking the coordinates, he ran back to the vox unit and called in the sighting.
"Well, you know what to do- destroy them!" came the reply, distorted through the a growing level of static in the vox net.
Plugging in the coordinates for the mass of chaos spilling towards them, he toggled the firing rune, covering his ears for the blast before shouting to his crew, "We have chaos headed straight towards us!"
Starting to direct their fire towards the column of chaos abominations and cultists dashing towards them, the basilisk tore chunks out of the mass, sending sprays of rock, gore, and bodies skyward with each impact. New orders were sent out, and one by one the other guns joined in, the column almost disintegrating as it ran, the few that made it close to the lines being quickly dropped by the infantry there before they could close to where they could do any appreciable damage.
And then a strangled cry rang out over the vox net, shortly followed by a different message, consisting simply of cursing and screams.
And it was about then that they heard the twisted battle cries and roars of the chaos army, heard so many times before- from behind.
Screaming at the driver to turn them around, Jacen drew his laspistol, motioning for the others to do the same. As the basilisk turned almost painfully slowly, he climbed up onto the edge of the gun deck to get a better view of what was facing them.
It was a horde. What seemed to be half the population of the city had somehow snuck up behind them, and was now charging them, armed with autoguns, wrenches, stubbers- you name it. Ducking back down as the horde took notice of him, he grimaced at the stench of the diseased cultists. Scrambling back up so that only his head was visible, he raised his laspistol and was about to take a shot, staring down at the oncoming mob of plague-ridden cultists, when a hand grabbed him by the collar of his shirt and pulled him back.
He landed hard on the ammo cases that made up the floor of the gun deck, lasgun skittering out of his hand and across the floor. Orde stood above him, shaking his head as small arms fire began to clatter off the sides of the basilisk. "Don't draw attention to yourself!" he shouted over the din, handing Jacen his laspistol and running off help load the heavy bolters.
After what seemed like an eternity, they were finally facing the oncoming horde, and the heavy bolters started their deadly work, a shower of rocket-propelled explosive shells slamming into the oncoming horde and slowing it for a second, even as the engine kicked into reverse, sending them jolting backwards towards friendly lines. Jumping down to the pilot's view slit, he watched what he could as they fell back.
Clumps of cultists dropped, exploding under bolter fire in sprays of dark ichor and gore, dismembered limbs flying back through the air to land among the cultists. The line spread out as he watched, the horde spreading even further down the line. Looking around at the nearby basilisks, it seemed that not everyone was as lucky as they were- there were several nearby going up in in flames, or swarming with cultists waving bloody weapons and smoking guns.
Checking behind him, Jacen scanned the thin row of Chimeras and Leman Russes that they were backing towards, many still turning even as turrets swiveled to face the oncoming horde of chaos, spitting hot death.
Looking back to the front, though, Jacen saw an issue- they weren't moving nearly fast enough. While the heavy bolters up front were buying them time, they could only target the cultists directly in front of them, and whenever they stopped to reload, the lines surged forward. They were gaining on them, and there was nothing he could do about it, at least for the time being, while they made their way towards the relative safety of their lines at what seemed like a crawl.
Time seemed to grind to a halt, each staccato beat of the heavy bolters seeming to mark the beats of his heart as the tracks moved, link by link, across the rocky ground, inching them towards their comrades, even as cultists overtook one basilisk after another in what seemed a macabre carnival of fire and destruction, shots pouring into exposed crew compartments, mowing down the crew members of those who were too slow in turning.
They finally made it, crawling back between two chimeras, multilasers blazing away at the oncoming horde. And it was about right then that the heavy bolters ran dry.
This was to be expected, honestly- the bolters were meant more as a last-resort weapon than something to be used all the time, seeing as how the Basilisk was an artillerypiece.
But they DID still have the main gun.
Shouting orders, Jacen started directing the main gun towards the stretched-out lines of cultists streaming towards them, the gun elevated as low as possible before letting out an earthshaking roar as it spat its massive payload not 200 meters away. The ground erupted in a gigantic spray of earth, rock, gore, and bodies as the shockwave tore through the air, shaking the ground and the tank.
Not pausing to admire the carnage, they started loading the gun again- they had work to do.