"Tech Priest?" asked the guardsmen over his vox ponder as he and his men marched through a swampy bog with the thick grey sludge sticking to their combat fatigues. It was a platoon, all dressed in typical faded brown fatigues with green cermite chest plates, all moving in unison across the barren landscape, fanned out just in case of an enemy ambush.
"Corporal Ygver?" replied a voice over the vox ponder with a hint of pity. Such was the bane of the Imperial Guard to be reduced down to mere sacrificial servants in the eyes of the Tech Priests of Mars.
The guardsmen continued to stroll through the knee high bog with his lads as thunder loomed over the horizon, sharding blue lightening across an otherwise dreary grayish hue sky, "We are approaching the anomaly. How do things appear on your end?"
Far into orbit, a tech priest stood at a cogitator station, green data scrolling down plasma monitors, his half metallic face shadowed in scrolls and scrolls of vast numerical text. Such information would be far too much for the average human mind to absorb, but… for a tech priest, it was trivially absorbed and dedicated to memory.
"Nothing new," he replied from an imbedded vox inside his throat, while not moving his mouth, "The anomaly appears to be maintaining its consistency. You are nearly there… just another five hundred meters."
The Corporal nodded and waved his men forward across the swampy terrain. His eyes suddenly widened as the sight of a luminous blue wisp of energy appeared atop what looked like a vast stone monument. This, structure, some sort of primitive pyramid of stone, it rose out of the swamp like a dagger only to have its summit flatted like a plateau.
"These ruins are ancient," noted one of his fellow guardsmen as they all ascended a primitive series of stone steps towards the monuments summit where the wisp of blue energy was at its thickest.
Suddenly, something happened. In orbit the Tech Priest watched as the data algorithms spiked beyond his cogitator's ability to process them. His mind, it was overwhelmed with raw information from some sort of vast entity; it was too much to process. He screamed loudly as blood started to trickle from his eyes, nose, and ears; before dropping to the ground unconscious. Numerous human crew members aboard his observation ship ran to his aid, while things upon the planet changed in a very unpredictable manner.
The commanding guardsman and his platoon stood guard atop the stone monument as a torrent of energy suddenly spiked all around them. This wisp, it started to spiral and form a void, a portal at its center. The guardsmen all at once went to the ready, their Lasrifles aimed at the portals center.
And then, that was when it appeared. Stepping forward from the portal, it was a… person… dressed in mechanical armor of unknown origins? This armor, Tau… no… it was shaped similar to Tau, but its function was much more like a space marine with its groin, arm, leg, and chest guards.
No matter, this creature's origin, it stepped forward with its hands raised and weapons stored. The weapons, a strangely shaped sword with a long sleek curve and some sort of alien rifle with a battery magazine, "I mean no harm humans… I serve a purpose and time is short," he said.
"Identify yourself?" barked the Corporal with his Lasrifle aimed towards this creatures helmeted head with two ornate decorative horns upon its helm.
The strange soldier stopped his march forward just beyond the spiraling portal and nodded curtly, "I am… it is complicated," he sighed, before slowly going for a paper scroll upon his waist.
"Easy!" yelled one of the guardsmen. The strange alien soldier that had appeared from the portal with his horned helm nodded slowly while unhooking the scroll from his waste, and tossing it towards the commanding human. The human, Corporal, caught the scroll easily.
"This message is important," said the alien, "Make sure that you get it to Earth. I wish that I could say more, but… I do not have much time here. This portal will not stay open much longer."
"Who are you?" asked the commanding guardsman as he held the message in his hand with the Lasrifle lowered slightly at ease.
"I am…" the other creature stopped and shook his head, "There is no easy explanation."
"Try…" said the human, sounding more like a command.
The alien nodded and glanced at the portal, eyeing its stability with a hint of concern, "The Warp separates your universe from our own. This message comes from one of our leaders. It's an offer for an Alliance. Diablos, the opposite of your Slaanesh, threatens our universe. You must understand… this offer is not being made lightly. In our universe humans are…"
The Portal started to swirl and twist, distorting wildly. The alien creature turned sharply back and forth as if set at unease from some sort of unknowable threat.
"I don't have much longer. This message, this leader… he is not like the one from your universe. He actually hopes to protect humanity from the evils of its Chaos God. Make sure that it reaches your leaders… they must read it."
Before the guardsmen could do anything, the alien leapt back through the portal seconds before it collapsed into an electrical discharge. The portal, it was gone just as mysteriously as it had appeared. The Corporal, in his curiosity, opened the message and started to read the text. To his surprise, it was in High Gothic…
If you are reading this message then the Divine Empress of the Eldar has succeeded in opening a breach between our two opposite realities. The person that just addressed you was an Eldar Royal Dragoon, this universes version of their Space Marines. I won't lie to you because the truth of this encounter is a harsh one. The Emperor in our Universe awoke as the Chaos God Diablos in the 31st Millennium, instead of the Eldar Chaos God who awoke in your universe as Slaanesh. Humanity is on the verge of extinction. Earth, Sacred Terra, lies at the Heart of the Eye of Terror instead of the Eldar Homeworlds. The Empress, she is this Universes version of your Emperor, and I… one of the last surviving Primarchs have seen the unfortunate truth of what is soon to pass. Humanity, what remains of it… is about to be consumed from within and there is nothing that I can do to stop it. Given how badly we fare, what remains of the Astartes have joined under my leadership in forming an intern government on Macragge, and we have collectively joined sides with the Royal Dragoons, but… with the bulk of our species consumed by darkness… our destruction is nigh. Therefore, I have made a fateful decision… we need to evacuate whatever humans we can from our universe and consider the remainder lost. Please, deliver this message to your Terran Emperor; make it known that human lives are on the line, and that if he does not authorize our evacuation… humanity in our universe will become extinct.
Sincerely,
Chancellor of Sovereign Humanity Primarch Horus.
"What is it?" asked one of the guardsmen to his commanding officer as he finished reading the message while scoffing at the name of the letters sender.
"Nothing," replied the Corporal as he crumpled up the letter and threw it into the swampy bog, "Just some foul Xeno's trick that nobody in their right mind would ever fall for…"