Never forget, never forgive! The Dark Angels are among the most loyal servants of the Emperor, who stand foremost amongst the Space Marines, Mankind's mightiest defenders. Since the founding of their Legion, they have been dreaded by their enemies and held in awe by those they protect. Stubborn and relentless in battle, they are ever vigilant in their pursuit of Humanity's enemies. Yet it was not always so. For ten millennia the Dark Angels have harboured a sinister secret, knowledge of an act so terrible that it threatens everything they hold dear and may yet bring them eternal damnation.