" The angel had looked at him for a long moment, the eyepieces in his cracked helm an emerald glow in the dark. ‘It is the Death Lament of Baal,’ he had said, at last. ‘The song of passing from the world.’ ‘You are singing of your deaths because you know we will die here?’ ‘To die is our purpose. "

― John French , Mortis (The Siege of Terra #5)