Author's note: I must confess, before we go any further, that I am not the most familiar person with40K lore, nor do I possess any extraordinary writing skill with which I can atone for my various mistakes. I am only a fan of both the 40K series and the Left 4 Dead series, and would like nothing better than to see the crossing of the two glaringly different stories, and of course, to see Hunters being shredded by heavy bolters!

This is my first published story, so go easy on me, constructive criticism would be very much welcomed, of course, praise in places where it is necessary would be doubly welcomed :)

The story is mainly about a space marine fleet from the Temple Chapter being lost in a warp storm. The storm sends them back in time, back to earth before the 41st millennium, where they encounter the zombie infection in the left for dead series.

The Temple Chapter is a chapter of my own creation, so you won't find them anywhere else, I hope.

0200 hours, Astartes Battle Barge Indomitable, in low orbit around unknown planet.

"Brother Ondius, report." Brother-Captain Avrus Destrol ordered, voice calm and steady. Destrol stood behind the command console in the bridge of the Indomitable, his massive frame made even larger by his ornate power armor.

"Warp travel successful, captain," the deep, robotic voice of the Techmarine said, standing behind Destrol, consulting a data-sheet build into his armor's glove compartment. "Although," he said, "I am yet to be sure of our location after going through the warp storm."

Destrol clenched his fists behind his back, he gazed out towards the ship's viewscreen, at the small planet that spun slowly on its' axis before them.

"Give me the name of that planet." He demanded.

"I have consulted the other techpriests, they have all reached the same conclusion, although we find ourselves hardly capable of believing the results we've obtained."

"Which is?"

The Techmarine paused to draw in a deep breath.

"It would seem that the warp storm has not thrown us into another dimension, instead, it has sent us back in time." He gestured to the planet. "I believe that we are looking at none other than Holy Terra herself, captain. Before the time of the Imperium of Man, before us."

Destrol spun around to stare at the Techmarine.

"Is such a thing possible?"

"I believe so, captain, the planet's location bears a shocking resemblance to the maps around Terra. Although there is something far more troubling below."

"Troubling?"

"Yes captain, we've already run preliminary scans on Terra's surface, it appears to be habited, by humans that have no knowledge whatsoever on the Imperium."

"They have not yet seen the Emperor's Light." Destrol muttered to himself.

"The Emperor, has not yet graced the galaxy with His arrival, captain."

Destrol paused to consider living in a galaxy where the Emperor did not exist, and couldn't fathom the possibility.

"Emperor save us." He said, the irony of his words did not escape him.

"Even more disturbing, captain," the Techmarine went on, "is this feedback that we have received from our surveillance probes one day after our emergence from the warp." He activated a link from his armor.

Destrol's command console winked to life, and he saw the streets of a city, the buildings were many, and all were devoid of Imperial influence. He saw the streets crowded with people, and it was then that he saw the horror below.

The streets were packed with hordes of shambling humans, they were covered with blood, and many showed signs of decay or rot on their bodies. They ran after the few humans who appeared normal with a speed that normal humans could not match, and butchered them with a barbarity that showed an uncomfortable resemblance to Khornate cults.

"Damnation of the deepest bowels of the warp……."Destrol muttered, his normally stoic face showing something akin to horror. "It seems as if the taint of Chaos has touched the holy planet." He gestured at the screen. "The foul work of the plague god, Nurgle. This sacrilege must not go unpunished!"

"Captain, is it possible that our planet has been touched by Chaos long before our Emperor?" The Techmarine half-whispered, as if the very thought was unthinkable.

Destrol set his jaw.

"Then we must cleanse it in the name of the Emperor, for the sake of humanity." He turned to the Techmarine.

"Ready our battle brothers, we go to war."