In the Grim Darkness of the 41st Millennium: there is only constant war and death. The Imperium struggles to stand strong. The Eldar strive for survival. The Tau seek out their destiny. The Necrons move to reclaim their former glory. The Tyranids continue consuming to sate their endless hunger. De Orks go WAAAAGHH!. The Citadel just doesn't have enough dakka.