This article, Siege of Calderia, was written by 40kfan, Shisaac, and T42. Please do not edit this article without their explicit permission.

Calderia was once little more than another miserable Hive World of the Imperium of Man, home to billions of downtrodden factory workers and vile underhive scum, but the "tranquility" of this world was sorely broken by the ravages of horrid Tyranids of Hive Fleet Chimera. Though valiant Space Marines of the Marines Baleful landed to aide the PDF in stemming the tide, an unknown threat came from the stars, the King-Goy... who came with the full intent of purging this world and all those on it in fire... lest the Great Devourer escape.

Prologue: The Chimera Cometh....

They were coming.

From across the blackness of space, horrid shapes swam through the darkness. Ships of pulsating flesh and frost- rimed chitin glided through the void, driven by a malevolent intelligence. This hive- fleet's destination lay before it, a single lone world, Calderia. It had no major importance to the Imperium to which it belonged, no strategic assets, but the Hive Fleet cared little for those things. They were hungry, so hungry, and at last that hunger would be sated with the death of this planet and it's billions of inhabitants. Nothing could stop them.

Hive Fleet Chimera had come.

Chapter 1: The Arrival

The Planetary Governor, Henrik von Lundqvist cared nothing for the peasants of Calderia. The Hive world was nothing more then a a mega city and had little importance to the High Lords of Terra. As long he sent Troops to the Imperial guard, he was free of do anything with the world. He and his fellow decadent nobles had no concern for the lives of the Calderian commoners.

"Summon a Council. We need to discuss the food shortages." he said to a nearby servant.

Suddenly the ground shook.

Lunqvist rushed to one of the balconies to see what the commotion was, and stopped dead in his tracks as soon as he looked to the sky. Hovering over the mega city, wreathed in the polluted atmosphere like some nightmare brought to life, was an abomination. An armada of living ships, each one more grotesque than the last, sat in the clouds. The Governor watched, terrified, as the flesh- ships disgorged thousands upon thousand of alien monstrosities onto the surface of Calderia. The air rang with screams, alarms, and gunfire as the Calderian PDF mobilized to repel the invaders, as feeble as their resistance would be.

Lunqvist stood there, rooted to spot with shock and fear. He had never seen these xenos in person before, but he had heard the stories. They came in their millions, devouring entire worlds. They were deadly, cunning, and utterly devoid of mercy.

"Tyranids." whispered Governor Lunqvist, as his world fell apart around him.

Chapter 2: No Mercy For the Weak

He ran, oh did he run, his heart pounding, his head throbbing, but run he did...but it followed. Jason rounded the corner, but his precious cargo, an infant bundled neatly in cloth, slowed him down..and it was hot on his heels. The corridors were dark, just as Father and his elder brothers liked, but now Jason would kill for some light. He glanced over his shoulders an immediately wished he hadn't, it was right there, eyes burning red like lasfire, teeth the size of carving knives glowing in the darkness.

It was a mass of shadow and steel, its Power Claws ripping into the walls to create flashes of light and cast inhuman shadows as it neared. All of the sudden Jason felt his legs vanish from his body, one moment they were pounding, the next, gone. He heard the rip of bone and flesh and the sizzle of disruptor field eating through bare skin. He fell, the child, his brother, rolled into the put its foot on his back. Out of the corner of his eye, he saw it, wrapped in a robe like the reaper, power claws sparking.

It snarled as it lifted its claw for the killing blow, then a screech, and a flash of claws, one of Jason's brothers had the beast pinned, it raised one of its scything talons to slay it but the brute bellowed and drove its claws deep into his flesh, forcing them into the shadows. Jason dragged himself along by his arms, and found the infant still cradled, still asleep.'

A sicking crunch and a squeal, and a disheartening thump filled the hallway, it strode into view.. a chilling laugh filled the air as it tossed his valiant brothers head into full view, his mouth still twitched. Jason cradled the head, and brought the eyes to a close... "" he whispered as it tore into him...tore into sinew and flesh, splashed gouts of blood across the walls, shredded bones with contemptous ease. Then a hideous squeal reached its sensors, it turned its eyes to the bundle... shoved the creature over.. revulsion filled its black heart.

The hideous Gene-Stealer half breed screeched in distress as the Agent lifted its massive boot over it, it tore free of its blanket trying to crawl on its misshapen limbs and claws, a final, angry squeal violated the air around it before a satisfying wet crunch heralded silence.

"No mercy...for the...weak." It said in the human tongue as it ground the remains into the floor, then a sound...a slavering hiss. It turned, a pack of Purestrains stood before it, "You..." It was Jason's voice that sounded as it spoke, it strode towards the Gene-Stealers, "monster...ahahahhah!" 

Chapter 3: Enemies Within

Day 15

Vengeance, Sergent of the Marines Baleful, looked out over the massive hive city, now a battlefield, and scowled. The midday sun glinted off his midnight blue and bone colored power armor and the faint breeze shifted the bone- white hooded cloak that he wore. It wasn't that the scenery bothered him, but something was off, he could feel it. He and the other Marines Baleful had been sent to Calderia to defend it from this "Hive Fleet Chimera" as it was called. Calderia wasn't exactly a major asset to the Imperium, but a Hive Fleet was a very serious threat and the Grand Master wasn't taking any chances.

Two full companies, the 2nd and the 5th to be precise, had been sent to stem the tide of Tyranids. Doing that was easier said than done, but the Marine Baleful had done exactly what they had been ordered to. Hold back the Tyranids and evacuate the planet's populace, those were their orders. They weren't even half done with the second. As thousands had been evacuated, millions more were left. Luckily, some of the mega- cities districts were fortified, and so the civilians were herded into these bastions as the Marine's Baleful and what remained of the Calderian PDF patrolled the walls. Just as Vengeance was doing now.

One of his battle- brothers contacted him via vox commications.

"Sergeant, we have xenos activity at the west gate!" the Space Marine voxed.

"What kind of activity?" Vengeance replied.

"Another Genestealer cult, sir." said the Marine Baleful.

Vengeance cursed under his breath even as he motioned for a few of his squad members to follow him. As the Siege went on, the Tyranids used more insidious methods of warfare. One of these was the genestealers that would sometimes slip through their defenses and use their corrupting talents turn the populace against them. One by one these cults sprung up, forcing the Marines Baleful to kill those they were supposed be protecting.

Vengeance ran full tilt, his armored boots clanking against the stone scaffolding, until he reached the West gate. Outside of the walls five marines, clad in midnight blue and bone power armor, and 2 dozen Calderian PDF soliders fought a huge mob of glassy eyed civilians wielding makeshift clubs and stolen las rifles. Vengeance leaped from the wall, landing so hard the cobblestone street cracked. Landing behind the defensive line of Space Marines, Vengeance drew his chainsword with one hand and his bolt pistol with the other.

"Their Souls are Forfeit!" he roared, as his squad moved to reinforce the Imperial defense.

Running forward, Vengeance fired into the crowd, turning several of the cultist's heads into bloody mist. Reaching the main mass of the mob, Vengeance swung his chainsword left and right, the weapon's adimantium teeth scything the genestealer cultists into chunks. His battle- brothers covered his rear, pumping bolt rounds into the cultists than tried to flank him. A burst of las- fire hit his shoulder guard, glancing off the ceramite. Vengeance spun around a full 360 degrees and decapitated the skinny cultist that shot him. Suddenly, an enormous shape came out of nowhere, hitting him and knocking him to the ground. A genestealer stood on his chest, it's tan flesh and serpentine form marking it as a member of Hive Fleet Chimera.

The genestealer snarled, saliva dripping from it's fanged mouth. Two of it's arms held Vengeance to the ground, while it raised it's other two arms, each hand tipped with diamond- sharp claws that could slice through ceramite with ease. But, just before it could rip Vengance's throat out, a volley of bolts knocked the Tyranid off of him. Out of the corner of his eye, Vengeance could see Honorable, one of his squad members, re- aiming his bolter at the wounded genestealer. Quickly getting to his feet, Vengeance rushed the alien, not giving it a single second to recover. He dealt the genestealer a terrific uppercut with his chainsword, slicing though it's lower jaw and destroying it's brain, killing it.

Vengeance, soaked in blood, looked around to see a sea of corpses. The cultists and their genestealer masters were dead, their blood pooling in the streets. But as he looked further, he saw a number of PDF soldiers dead as well, not to mention two of his fellow Marines Baleful. He saw the corpse of his battle- brother Conflict lying face down next an eviscerated genestealer. 

"Gather up our brother's bodies and bring them inside to the apothecary." He said to Honorable, gesturing at the space marine's corpses.

Honorable nodded his consent and proceeded to collect the bodies of the fallen. Vengeance sighed inwardly, these losses weren't exactly staggering, but with each day the Marines Baleful's forces grew smaller and smaller, and now Vengeance was seriously starting to doubt that they could hold out much longer.

It's only a matter of time before the Tyranids come in numbers we cannot defeat, he thought grimly.

Chapter 3: The Storm Breaks

Day 40.

A thousand more civilians had been evacuated. But still billions more had yet to be evacuated. The Shadow in the Warp has intensified and their best astropaths had fallen to insanity. Company Master Arbiter of the 5th Company has ordered Tactical Squad Requiem to go to the city wall. There few PDF soldiers left, many committed suicide. They couldn't stomach another wave of the Tyranids. Something that fellow squad member, Requital seemed to take pity on. After all, Space Marines somewhat are human, despite their enhanced augmentations.

"Company Master.. Tyranid swarm coming out of the tunnels. Permission to man the turrets?" Sergeant Havoc asked to his brother-Commander.

"Permission granted.. let the bastards taste the wrath of the Emperor! WE cannot afford to lose the wall!" He shouted over the vox communication array.

Havoc smiled. "Squad, let the cannons lose." As on cue, his squad fired the Calderian pattern Assault Cannons. A volley of shells shredded the first wave that was swarming the tyrannoformed landscape. A few of the snake- like hormagaunts were torn to shreds. But they were expendable. Their fellow species just swarmed over them like a bothersome obstacle. Kill two, five take their place.

Nonetheless, the swarm began to scale the wall. Typical of the swarm, cursed Havoc. The Hormagaunts continued to scale the wall and judging by the size of the wall they were half-way. Havoc ordered five Marines who had  boltguns to rain down bolts into the wall to stem the tide. A second later, Bolts were raining down among the Tyranids. Limbs flew into the air as Hormagaunts blew apart into a crimson mist.

Still more Tyranids came.

"Squad, fall back! Retreat to secondary defense positions!" Havoc yelled.

He and his squad leaped from the the wall just as the Tyranids swarmed the over it. Then suddenly the entire first row of Hormagaunts fell dead, each one having received a bolt through the skull. Looking up in surprise, Havoc saw an entire Marksman Squad perched in the rooftops above them. Each member of the Marksman Squad carried a Stalker Bolter, and knew how to use it with deadly efficiency. Havoc smiled once more.

"Didn't know you would be joining us, brother." voxed Havoc.

"Someone had to cover your sorry hide, Havoc." replied Truth, leader of the Marksman squad.

Havoc grinned underneath his helmet even as he and his squad fired into the horde of Tyranids. The mass fire coming from the two squads killed scores of Tyranids. But still they kept coming. Larger Xenos climbed over the wall, these ones stood on two legs as they aimed strange bio- guns at the Marines Baleful.

Warriors, thought Havoc, as he set his bolter to full auto. He emptied his rounds on one, making the Warrior convulse as the mass- reactive rounds tore it to sheds. Another Warrior fired a blast of bio- acid from it's flesh- gun, hitting Requital. Requital screamed in pain as the acid ate through his chest plate and burned his bare skin, causing him to drop his guard long enough form the massed Hormagaunts to swarm all over him.

Another blast of acid claimed the life of another one of Havoc's squad members before one of the Marksmen killed the Warrior with a bolt through the eye. A third Warrior's bio- gun released a swarm of living bullets that hit Apathy, one of Havoc's squad members, burrowing through his armor and into his flesh even as Havoc shot the Warrior to pieces. He could only watch as the Tyranid organisms killed Apathy, devouring him from the inside out.

"Hold fast brothers!" Havoc yelled over the screeching and gunfire. "Defend this position with your lives!"

Then the ground exploded, knocking Havoc and half his squad off their feet. Burrowing up from the depths of the earth came a massive brute of muscle and chitin. A Carnifex. Havoc tried to recover but it was to late, the alien abomination stepped on him, driving him into the ground and cracking his power armor. A huge bone talon scythed down to impale him.

May the Emperor protect the others, thought Havoc, as the Carnifex's talon ended him.

Chapter 4: Break Them

Commander Tah-Soh-Kan stood over the bloodied remains of a pack of Hormagaunts, his Auto-Pistol still smoking, wrist sword still crackling with disrupter energy. "These Slaak are strangely shaped, nothing like the previous hordes..." Tah-Soh-Kan thought to himself. Long had he battled against the Slaak, or as the Hethgre called them, Tyranids, but he had yet to see specimens of such an odd design. He shrugged off his skeptisiem, the Changers could come in innumerably grotesque forms.


Tah-Soh-Kan turned to face one of the Agents that had led the Pack to this infested world, Tai-Uut-Set was his name, his power claws crackled with energy and the gauntlets were long stained with Gene-Stealer blood, his left boot was also stained with a more red hue of fluid. Tah-Soh-Kan nodded, knowing the Agent was going to divulge some key tactical information.

"The Hethgre have established a bastion in the southernmost area of the population center, they have... Sna-Tons." Tai-Uut-Set spat the name of the Gene-Warriors who served as the vanguard of the Hethgre armies.

"It matters not, they will be put to the blade with the rest, the infection must not spread." Tah-Soh-Kan turned his back on the Agent, and strode towards the open courtyard where the warriors of his Lance stood at attention, ready for their final orders before they dispersed and brought death to the vermin. He stood before them, the Sai-Lek, or as the Hethgre called them, Runts, were fidgeting about in stark contrast to the King-Goy Troopers who stood beside them... they were no warriors, the sounds of battle unerved them. 

"My Brothers!" Tah-Soh-Kans voice boomed over the courtyard, causing every Sai-Lek to leap to attention, "The infection has taken root in the northern area of this population center, we are to clear it of taint! As for the hethgre and their gene-warriors, squads 1 through 25 will prosecute their elimination! Glory to us, for the Dominon's will is with us! IN THE NAME OF THE GREAT DESPOT, BREAK THEM!"

A roar tore throught the Lance, and the Sai-Lek fired into the air in their fervor, then they dispersed, vanished amongst the rubble and corpses. 


Strife stood, bolter ablaze against the Carnifex, the beast had slain Havoc, and Termagaunts burst from the ground near the Carnifex. Yet Strife refused to give to the swarm, soon Spirit and Angel stood beside him, but the tank of feral rage and hunger slid towards them, sweeping up Termagaunts in its horrid wake. Then as it raised its talons to sweep them aside a black shape leaped from the swarm, claws crackling with lighting as they ripped the Carnifexs lower jaw from its head. Strife and his brothers looked on as it slid to a halt, and with eyes burning like fire, roared in challange to the great hulk. The being was cloaked in black robes, looking like a visage of death itself as the Carnifex rushed to meet it, yet, like the Astartes it held its ground, the Carnifex arced upward, coming down on the Xenos warrior with all its might. The Xenos rolled to the side and dug its claws deep into the Carnifexes form as it plowed into the dirt, tearing organs from its body as it bore down. 

The Carnifex burst from the ground, blood spraying from a gash that ran the length of its body, the beast roared in agony and rage as it turned for another attack, but its fury met the Xenos' claws, which ripped its skull in half. As the Carnifex slumped to the ground, Strife and his Battle-Brothers fell back, the swarm was too great, but as they ran, they saw more of the xenos ripping into the swarm, not clad in robes as the first but none the less they were taking the fight to the Great Devouerer with a savage zeal. Termagaunts fought with smaller xenos, while their larger cousins tore into the Warriors of the swarm.

Truth and his marksmen Squad were still providing cover until their perch was blown out from under them by a blast of green plasma. A massive xenos with red markings then leveled his large plasma cannon at Strife and his fellows but suddenly fell into the ground as Termaguants burst underneath it like a gyser of fangs and claws.

One, clad in its black armor and brandishing a large rifle, leapt from a building top and drove Spirit to the ground, firing as it fell upon him. Angel drew his combat knife and slashed at the xenos that stood atop his now injured Battle-Brother, but his blade met one that sprung from the xenos' gauntlet, it delivered a vicous knee to his chest forcing him back, Strife leveled his bolter and let loose a volley, the bolts collided with an energy field that made the whole beasts body spark and course with arcs of energy, the xenos tumbled back, giving Spirit the chance to fire is own bolter, Angel followed suit. The alien fell underneath this hail of bolterfire, once its shields burst with a noticeable flux of energy, its suit was punctured by a well placed bolt to its "face", suddenly black fluid rushed forth as blood would, then a horrid shriek of agony as the creature doubled over, a volatile smell filled the air as it fell to the ground, dead.

"What manner of beast is this?!" Spirit managed as Angel and Strife hoisted him to his feet, he could walk, but the rasping in his voice showed that one of his lungs had been punctured. Strife sent out a Company wide vox cast, "Brothers beware! Unknown xenos have joined the battle, they are well armed but seem preoccupied with the Tyranids. Repeat, unknown xenos have joined the battle!"

Chapter Five: The Serpent Comes

PDF Seargent Finnian looked the over the wall, where a small hill of dead and rotting Tyranids lay. Nevermind their ferocity.. The smell is more noxious.. thought Finnian. He was right though, the engineered creatures rotted faster then any other creature in the galaxy.

He commanded only two units of infantry, what was left after the massacre in the Jaeger sector. A brood of Raveners bursted from below the city streets and pounced on the unwary. It nearly took two hours to slay the beasts and one of the Space Marines was killed in the outcome. At the rate the defenders were falling, it wouldn't be long before all of Calderia fell too. Even worse, reports had been coming in of a strange new threat. Xenos clad in black armor, standing as tall as Space Marines with blazing red eyes and teeth the size of knives. Finnian shudered, it just thinking about the rumors gave him the chills.

He reassured himself and looked over the landscape. The land had become a nightmare. Vast capillary towers had erupted from the earth. Organic towers blighted the landscape while a few miles away, an eerie, sick green color glowed in the distance. The gaping maws of the reclamation pools.

Then the ground trembled again. In the distance, about 50km; Finnian judged. a giant serpent like Hierophant bursted from the ground and emitted a eardrum shattering roar. It had 8 sets of large talons, that could slice a titan in half.  It then looked towards the city. Finnian swore that it looked at him.

Smaller shrieks and and roars followed as more and more Tyranids emerged from the ground, serpentine abominations that to Finnan looked as if they had burrowed up from hell itself. Like one massive organism, the Tyranid horde surged towards the city. Already the shouts and gunfire rang through the air as the Calderia's remaining defenders, Space Marine and PDF solider alike, desperately tried to stop the oncoming assault.

Finnan stood there, paralyzed with fear, as the Hierophant came closer and closer........

The serpents came, and there was no escaping them.

Chapter Six: Death, Blood, Carnage...

Death, Blood, Carnage...Death, Blood, Carnage... DEATH, BLOOD, CARNAGE. The words bashed themselves against Cho-Gat-Nak's skull as if they were the powerfists he possessed. The combat stiumlants ran through his mind like a red fog of malice and savagery, he wanted to hunt, to kill, to rip limb from limb. And soon he would have his chance.

The Hunter Gunship flew in formation with six others as part of a mass insertion of forces within the area known to the Hethgre as Jager Sector, it had been nearly overrun by the Slaak. Blood Packs, savage and large King-Goy, were to be dropped in as a vanguard. Cho-Gat-Nak smashed his fists together in anticipation, the rest of his pack clawed at the walls of the gunship and beat their chests, the hunt was near, they could smell the Changers blood on the wind as the bay doors opened. 


Marines Baleful stood against the swarm, vallaint alongside the terrified Calderian PDF, but the swarm was relentless. In the distance a Bio-Titan slithered forth, and the swarm around it ran like a tide of claws and fangs. Suddenly, strange aircraft sped over the horizion, and launched forth burning bursts of plasma and storms of fire upon the Tyranid Monstrousity. The Hierophant lurched to the side, bellowing in rage as the nimble gunships flew out of the range of its venom cannons. Only for one of the aircraft to be impaled by a talon from the top and resulted in a spectacular explosion.

Hunter witnessed this and the large forms that dropped from the gunships not to far from his post at the feet of the bastion walls. But he had little time to think about what manner of beasts that were unleashed there. As a mere Private in the Calderian PDF, he was not payed to think, he was payed to keep his lasgun blazing as the Tyranids swarmed his postion.


The ground shook violently as the spore ridden sky started to dim, the sun was setting and the moon was already rising; witnessing the death of Calderia. the earth began to violently shake as two more of the snake like Hierophants burst in a shower of earth. The first one, reacting to the gunships that fly over it. Genestealers were battling with these shadow cloaked figures. when of these figures are ripped to shreds, the others fight with more vigor.

The Hive Mind registered these figures as not humans. But some new alien species that is to be devoured. If will mean expending many warrior beasts against this menace to obtain such fruitful genes, then so be it. Warriors screeching loudly. A few seconds later, the call was heard by a tide of Raveners and Rippers swarm towards these menacing xenos in an attempt swiftly slaughter the brute like aliens. Two Raveners pounced on one of the cloaked figures. But as if some prenatural swiftness, the figure grabbed both serpents and crushed their throats, both monstrosities falling limp. But that was a main distraction and a swarm of Rippers swarmed that figure and drowned him in a torrent fangs and claws.

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