Author's note: I wrote this story for a GW short story entrance. They wanted a space marines vs ork battle in 2000 words, so I wrote a shorter version of what you will read now. It was, in fact, my first WH40k project (or first short story in English, for that matter). I liked the background story I conceived for it, but that I could not write, so I have extended the story a little (to 3500 words). It's still very condensed but I hope it's understandable. Although this short story is autonomous and doesn't need more chapters, I have thought a bit about how to extend the story. Perhaps I'll add more chapters.

Tyre was an agricultural world in sub-sector Phylos. It supplied almost all food for the whole region, a somewhat isolated area of space that for a century had not suffered any significant military conflict. And before the sub-sector invasion, the strangest event that had happened there was the reappearance, near Tyre, of a long-lost spaceship. The ship had once been a mighty vessel of the space marines Ultramarine's chapter, but by then it had become a deformed husk. How had it found its way through the nightmarish currents of the Inmaterium nobody knew, but the space marines -even if wary of the taint of Chaos- were grateful for such a boon and dispatched a retrieval team. Unfortunately, that ship was not the only thing that emerged from the Warp.

Sensing perhaps a new easy route through the Warp, orks entered and attacked Phylos space. They appeared in Acre's star system, the capital and industrial center of the whole sub-sector. At 240 million miles, the enemy fleet still had a long trip ahead of them, but it quickly became evident they were not interested -for now- in the planet. They had appeared, however, very close to the unprepared planetary defense fleet. Although they fought bravely and, in the end, desperately, the orks vanquished -at a substantial cost- the Imperial ships. After that, the orks did something very curious: they captured the main Imperial ship, a two-kilometer-long frigate, and then they just reentered the Warp.

Though mourning their fallen soldiers, the people of Acre were ecstatic for that miracle. They had called for reinforcements from a near sub-sector, but now it seemed they would not need them. The retrieval team of space marines near Tyre, however, were not so relieved. After millennia of battles, they understood the orks better than almost anybody and knew the creatures were more cunning than their brutish appearance indicated. So, when the highest astropath on Tyre received a confusing but terrifying signal from something coming from the Warp, the ten space marines knew what had to be done and what was at stake.

A week later, the captured Imperial frigate emerged from the Warp near an asteroid field between Tyre and the next planet. It picked one of the rocks and began to accelerate at a perilous rate on a collision course to Tyre. Meanwhile, the space marines waited inside their little assault barge, hiding it in front of Tyre's star, hoping its heat would mask their own. They programmed their ship computer to follow the enemy ship trajectory, so they would always be in front of the sun from the orks perspective. Not much more could be done but wait, so the techmarine did the necessary calculations, issued very precise orders to the ship's servitor, and then -along with the rest of the space marines- entered into a hypnotic-induced long sleep.

Two weeks later the electric signal awoke the servitor. As easily as regular humans would have perceived their hands, the drone began to visualize the information received by the ship sensors and all that had happened while the whole crew had been hibernating. Everything seemed to have gone according to the previous calculations, and only a few minor adjustments were necessary. The drone's unconscious functions had steered the assault barge correctly, and they were on route to the approaching enemy ship. Unable to understand the magnitude of his actions or the billions of lives at stake, the servitor followed the protocols programmed by his masters and ordered the ship to accelerate at an extreme rate. As the last action, he awakened the space marines, and they readied themselves for the crash.

Sergeant Aetius of the Ultramarines was the first to regain consciousness after the impact. Its force and the assault barge's acceleration had been extreme even for the mighty constitution and power armour of a space marine. Although still shaken, he felt pride when the nine space marines under his command awakened in unison and went immediately to their prearranged positions. He didn't have to order anything since they all had memorized the tactics, the schematics of the captured Imperial frigate, and many contingencies for the coming fight. Only the techmarine Val Marius seemed unresponsive, mesmerized by the sight of the dead human drone that had served as their autopilot and ship's computer. However, a quiet but terse order via the vox-caster was enough to spring him into action. With devout religious reverence, the techmarine picked the black box containing a power cell and began to pray and converse with its many spirits.

Once the destructive forces inside it had been controlled, the techmarine talked with the rest of the ship. Following his specifications, the barge's plasma torches began to cut through the weakened hull of the hijacked spaceship. It was a perfect incision except at a few points so the 'door' would hold strong even after the machines finished their job. Meanwhile, Val was putting explosives near those weak points.

Two groups of four space marines were, in straight and close formation, on each side of the future opening; between them a deadly tarantula sentry gun would offer them much needed support. Far away from any direct harm, the techmarine Val Marius waited while his servo arm and mechanodendrites protruding from his back embraced the black box as carefully as a mother would have embraced a child.

The plasma cutters finished their job and immediately the wall was greeted by a thundering hail of bullets sent by the trigger-happy creatures from the other side. Silence followed, but soon the space marines' superhuman senses picked the distinctive, cruel and roaring sound of the Ork's laughter.

"Timeus, Chiron. Hit the wall." Ordered the sergeant.

The two marines closest to the wall punched it with deceptive desperation, and a choir of mocking laughter was heard coming from the storeroom on the other side. A few seconds passed, and the sound of approaching greenskins could be heard. The footsteps stopped, and an inhuman guffaw was followed by the rasping sound of an axe grinding, tauntingly, against the wall.

"Now!" Said Aetius. The techmarine activated the explosives.

Hardly had the piece of wall (and the dying ork) begun to fly when the space marines threw flash and smoke grenades into the room. At once the spinning tarantula shot at the confused orks and tore their flesh while providing cover for the space marines' entrance. Their movements showed no confusion, haste, or waste.

Crossing half the room through the smoke, the warriors maneuvered elegantly and shot on the move. Like missiles, their bolts pierced most covers and the scant armour protecting the huge creatures, quickly exploding inside their ape-like bodies. Five seconds and almost two dozen ork casualties later, the space marines scattered and hid behind temporary cover.

"How's our barge after the crash? Will it survive as an escape pod?" Asked then the sergeant to the techmarine.

"It could be better, but unlikely" Was his laconic response to both questions.

For each score of bullets the greenskins wasted the space marines shot one, killing or gravely wounding one of the creatures. The orks weren't the greatest of shooters, but they compensated it with superior numbers and absolute indifference towards pain and ammo conservation. The orks screamed, laughed and shoot their primitive weapons as if the firefight was the greatest game or sport they had ever played; from the space marines point of view, only the sound suppressors inside their helmets prevented them from going deaf. Although the orks missed most of the time or the space marine's armour deflected the odd bullet, it was just a question of time the xenos overran them or began to use heavy weaponry.

As a painful reminder that there were worse things than those huge orks, the marines heard a hideous mechanical sound even above the painfully loud firefight. Though they could not see it, they knew it was what the orks called a 'killa kan', their primitive -but deadly- version of a heavy mechanical walker.

That was one of the studied contingencies, and the techmarine knew what had to be done. He knelt, not just for extra protection but also as a sign of respect and devotion to the machine spirits of the assault barge. He blocked his perception and thoughts from the outside world until everything went black, sensing only from time to time a numb impact from a bullet near him or on his armour. Then, he began to talk to his spaceship. Thanks to his augmented cortex and training, he could see and sense the machine spirits resistance to his commands, but he knew many codes, symbols and ideographs for overriding such -in other situations- logical precautions. After a few seconds, the machine accepted and began to disengage its locks. Val Marius returned to the normal reality and opened an emergency channel.

"Magnetize your soles and brace yourselves!" Shouted the techmarine.

The last remaining semblance of a rational gunfight stopped, and the aliens screamed as the hole in the hull sucked oxygen, boxes and orks into the void. Some resisted and were merely dislodged from their positions, but that was enough to become easy targets for the space marines. Meanwhile, the tarantula -the barge was still hovering close by- made mincemeat of everything flying in its directions. In the vacuum's complete silence, the techmarine observed the dark beauty of the machine's snapping movements and the slaughter it caused.

Though the vox-caster, they all received an urgent message. It was from Brother Cadmus, pointing at the now visible and unstable killa kan. It was going straight to the hole, but bumping and hacking into everything in its path.

Though he had warned the rest, Cadmus didn't dodge the thing in time and with its circular saws the spinning machine cut half of his head. The furious marines futilely shot at the back of the hideous thing as it passed dangerously close to them. Then it flew into the assault barge, crashing and sending them both to the confines of the universe. Though shocked by what they all had seen, the destiny of a planet and, perhaps, a whole subsector was in their hands; they knew they had to keep going.

At Aetius' orders, the space marines formed a straight column and walked through many tight and narrow corridors. Full of wrath, they took much pleasure in gunning down the occasional ork or random mob of cowardly gretchings. They were close to their destination when the techmarine sent a message to Aetius.

"Hundreds are hounding us." Said the techmarine.

Aetius always forgot the techmarine had a sonar in his skull and could, literally, see the entrails of any ship.

"Any plan?" The sergeant asked.

"Yes. It's also a shortcut, but it's unconventional." He pointed to a nearby service lift that didn't seem sturdy enough for nine space marines.

Aetius thought about it and remembered the ship design. "That doesn't lead to the auxiliary generators."

"No, it leads just above the auxiliary generators." He pointed at the explosive charges he was carrying. "I calculate we don't have much more time to divert the ship's course before we are overrun."

Aetius looked at him and then at the lift, repeatedly. At last he accepted the plan and ordered his warriors to ready themselves for the jump.

The orks had very strict orders from their Warboss about what to do with that spaceship. Naturally, they weren't happy about the space marines seemingly appearing from nowhere. The ork's plan should have been a simple but effective one: use the ship as a giant missile against the planet. The orks would flee before impact inside the asteroid, which would also crash on the planet but at a less suicidal velocity. At the current speed, after having spent all its fuel, the frigate would create a dust cloud big enough to plunge Tyre into a long artificial winter. The whole sub-sector agricultural output would be destroyed in an instant. After that, the rest of the ork fleet would wait a little so the big price, the very food-dependant Acre, began to eat itself; then it would be ripe for a real invasion. Knowing that, the mekboyz had realized the space marine's intentions and had set up another ambush, this time behind the giant blast doors leading to the auxiliary generators (the main one being too well protected already).

Strangely enough, the explosion and charging space marines didn't come from the front, as they had expected, but twenty meters above their heads. Some orks laughed and pointed their fingers at them since they believed the humans were falling. However, when the head of an ork exploded thanks to a well-placed shot, they realized the umies weren't falling but jumping.

One of the Ultramarines, Sergeant Aetius, was the first to land, precisely on top of a very confused ork. He aimed his bolt pistol and shot another one in its massive face, and then carved the half-dead creature with his chainsword. Quickly, the rest of the spaces marines formed a circle around the sergeant and the techmarine. The surprised beasts were gunned down quickly, but then others came in, charging. The space marines used the improvised ork defenses and held their position for two or three minutes. Then the thundering shootout died down quickly.

The orks had learned a harsh lesson, but the space marines still could hear them grunting and regrouping beyond their position. They greenskins were wounded, regrouping and planning behind the machines that littered the room, but they were still there and they were many.

During that short lull, they all regained a bit of calmness and Aetius could see in his visor that the rune representing brother Eolus was lifeless. He chose not to say anything. The room was huge, and many more orks remained.

"Sons of Ultramar!" He said immediately. "Protect Marius as if he were the Emperor himself. Move!"

Aetius hadn't finished the sentence, and four marines were already forming a human shield around the techmarine. The remaining three, including the sergeant, went in the other direction.

There was no time for subtlety; they just had to draw attention to themselves for as long as possible. As soon as Aetius and his companions stepped out from cover, a hail of bullets from two stationary heavy machine guns pummeled at them. Most shots missed, but some didn't, and their power armour was much less effective against such destructive force. The three marines were able to cross the four-meter wide corridor and hide behind an imposing crane. With his hand he signaled to his soldiers his orders; then, at the same time, they all threw grenades in the machine guns direction. Following the explosion, they stepped out and gunned the remaining alien figures.

Their victory didn't last long. A deafening 'Waagh' -the warcry of the orks- erupted near them, and a horde of greenskins came running and shooting in their direction.

Aetius ordered to fall back and keep shooting. One ork here or there died, but two more stomped or jumped over its body. Accompanying the sergeant, Iovis was the first to fall, killed by a bullet through his visor. But there was no time to mourn him, and a second later the wall of orks crashed against them. The other space marine, Quintus, fought viciously but in the end he was also killed. Only the sergeant was able to hold the horde thanks to his chainsword, but how much time he could keep them at bay, he did not know.

On the other side of the room, protecting Marius and the next to fall was young Timeus, gripped and dragged by a group of orks. There were dozens of them, and no matter how many were shot down, more came. The space marines had to keep moving and were unable to stop or kill all their pursuers. They helplessly watched as the green mob beat Timeus to death. He fought back, but in the end he could hardly move. Knowing he was doomed, his last action was to fiddle with something in his war gear. Then, while the green mass held him, the biggest ork among the group ripped his power pack and then cut his spine and throat with a power knife. The ork roared over the cries of wrath from the space marines, but from the beyond Timeus laughed last when one of his grenades exploded.

The vengeful explosion gave the remaining marines a necessary respite and cover for a few seconds, but it didn't last long. Jumping from a catwalk above their heads, the biggest ork many of them had ever seen landed on top of the machine Marius (and planet Tyre) desperately needed. The ork was hideous; more than three meters high, and its skin was covered with grafted metallic plates. Through them and into its chest, the creature had inserted a miniaturized version of an energy cell, smaller but similar to the one Marius carried. The glowing contraption seemed to be connected both to the ork's brain and to the enormous lascannon the beast wielded. The ork's stitched face grinned, and the beast pressed a button.

"Find cover..." Marius began to shout.

The blinding and silent flash quickly disappeared, and the damage done became immediately apparent: Bremius was dead, and his head wasn't attached to him anymore; Chiron –though still alive- lay on the ground without his legs. Only Val Marius and Janus seemed unscathed.

The ork prepared his next sweeping shot, aiming first at the techmarine. Marius, raising up the fastest prayer anyone had ever uttered, aimed his long-shafted power axe like a javelin and threw it at the creature's chest. The axe impacted into the power cell, but the result was surprisingly unspectacular. The alien didn't seem to mind the sinister humming the energy cell began to make nor the gaping wound in its chest. More disappointed than angry, the ork tried to blast them but the gun refused to work no matter how many runes the ork pressed. Ant then, in an instant, its head overloaded and exploded in a bloody electrical shower.

"Well, that was interesting..." Muttered the techmarine. Then, turning to his last protector. "Janus, cover me while I finish this."

While Marius worked, the legless Chiron expired at last but not before killing many unsuspecting xenos with his bolter. Janus spent his last two clips of ammo defending Marius' back, but in the end he had to use his own body for that. He helped himself of some orks bodies as shields, and when the creatures got tired of shooting at him, they charged. With his combat knife he slashed, stabbed, and wrestled with the greenskins. He won, barely, and was able to turn back the attacking orks, but weakened by the loss of blood he died there, standing, even before he fell to the ground.

Almost unaware of all that was happening near him, the enthralled techmarine and every mechanodendrite in his power armour conversed and screamed at the spirits of the ship, telling them to open what should not be opened, to close what should always be open, and to overload every possible thing.

He was already finishing when, from behind and very close to him, he sensed and heard two huge beasts, one with a chainsword. Val felt an icy sadness and guilt at the prospect of failing, but then surprise when his head did not roll, but that of an ork did. Relieved and surprised at seeing that ugly thing at his feet, he glanced back and saw that one of the beasts was Aetius, covered in so much blood it was difficult to see his blue armor. Although some still could be heard in the distance, no living xeno was in sight. The sergeant muttered something and then fell unconscious, hurt, but alive.

The techmarine returned his attention to the machine and recited to it the last command. As an answer, the machine sang a very short and unnerving litany of warnings that echoed throughout the room. A few seconds later an even worse alarm was heard throughout the whole ship.

"It is done!" Screamed the jubilant techmarine, raising both his arms in the air.

Throughout the ship, too many essential systems began to malfunction and explode.

The spaceship moaned, creaked and, finally, veered away from its course. In contrast to his crumbling surroundings, the techmarine was calm and content. Planet Tyre had been saved; that was all that mattered, and he had never felt so satisfied. Ignoring the destruction that was happening around him, the techmarine checked his sergeant armour. It was in bad shape, but he believed it would hold. He also hoped Aetius' Sus-an Membrane would keep him alive; and his own, for that matter.

Burning orks screamed and fled to their deaths in random directions. Amid the flames and melting metal, without a hint of fear and with his own power armour almost at a breaking point, the techmarine hold with care the unconscious body of his last living battle brother. He closed his eyes, ordered his armour to keep emitting a specific radio signal, entered into a meditative trance, and waited. When a huge tear in the spaceship hull appeared, he didn't resist and let the void draw them in.