In the underworld, a labyrinth of tunnels separates the world of the living from Hades, the world of the dead. Souls who refused the passage of Styx found themselves lost in the maze wandering the depths for eternity. One by one, their senses would fail them: Darkness invaded their eyesight; humidity suffocated their touch. Smell and taste were forgotten. Hearing was the last to go. Thus to find each other, the souls would shout words into the abyss, hoping to elicit a response. This caused much confusion as the cacophony of voices was near indecipherable. One soul, whose name was Echo during life, began repeating the voices she heard. Hearing one’s own voices repeated, other souls were drawn to her, eventually finding one another by adopting her system. As the groups expanded, their collective voices grew louder and could often be heard by the living when shouting into the deep.