Source: Exotic engrams; extremely rare world drops.

Lore

True freedom is an iron-clad lock And the most useful key, a rock The tastiest spice is hunger And the truest certainty—wonder. The best repair is but destruction, The purest ignorance, instruction The safest shelter is an offensive, And to fall in battle is true ascension Brothers and sisters, bear thy arms and be merry To the front, to battle! Defeat is a sickness and we've found the cure