It is the forty-first millennium and war rages through the universe, the uncountable and immeasurable forces of humanity stand toe-to-toe against the heretics of Chaos and the many different Xenos on many battlefields and in the cold vacuum of space. While the war is most prominent on the minds of those across the Empire, mothers, sisters, brothers, fathers and sons frequently saying their farewells to the billions that fight daily for their survival, there is another battle hidden in the everyday lives of the 'normal' folk, a battle far more deadly and, in many ways, far more important than the wars on the front lines of the Empire. It is a war not fought by Space Marines or Imperial Guardsman, nor by Titans or The Holy Fleet but by the Acolytes that bleed, kill and die to keep the corruption at bay. You are one of those Acolytes, proud and bound by your oath to breathe your last breath in service of the God-Emperor of Mankind, purging the Chaos with fire and righteousness... This is our war, our battle. FOR THE EMPEROR!