For more than a hundred centuries the Emperor has sat immobile on the Golden Throne of Earth. He is the master of mankind by the will of the gods, and master of a million worlds by the might of his inexhaustible armies. He is a rotting carcass writhing invisibly with power from the Dark Age of Technology. He is the Carrion Lord of the Imperium for whom a thousand souls are sacrificed every day, so that he may never truly die. Yet in his deathless state, the Emperor continues his eternal vigilance.
Vast armies give battle in his name on uncounted worlds. Greatest amongst his soldiers are the Adeptus Astartes, the Space Marines, bio-engineered super warriors. Their comrades in arms are the legions of the Imperial Guard, countless planetary defense forces, and the ever-vigilant Inquisition.
But for all their multitudes, they are barely enough to hold off the ever-present threat from aliens, heretics, mutants, and worse.
To be a man in such times is to be one amongst untold billions, and no matter how heroic your death, you will not be missed.
Forget the power of technology and science, for so much has been forgotten, never to be re-learned.
Forget the promise of progress and understanding, for in the grim darkness of the far future, there is only war.
There is no peace amongst the stars, only an eternity of carnage and slaughter, and the laughter of the thirsting gods.
As an Acolyte of the powerful Inquisition, you will root out threats to the Imperium of Man. You will engage in deadly combat against heretics, aliens, and witches. You will face Daemonic possession, and battle for your very survival amidst a web of conspiracy and betrayal. But perhaps the biggest threat you face is your fellow man, for the human soul is such fertile ground for corruption.
It is your duty to shepherd mankind from the manifold paths of damnation, with a smoking boltgun if necessary.