Many years after a global war that almost completely destroyed humanity, the few survivors are trying to build a new life in the Cocoon community. Their survival is threatened by a dark substance known as Erosion, which spreads uncontrollably and creates a hostile, post-apocalyptic environment.
To face the threat, humans form a militia aiming to destroy the mysterious Living Tower. At the center of the story is Syd, a determined warrior who meets the enigmatic Filena, as they ascend the living and constantly changing tower together, seeking answers and uncovering the truth behind Erosion.