Once every hundred years, the cursed labyrinth known as the "Abyss" devours the world.

News arrives that the king has been captured by Helmut, the great monstrosity reigning at its deepest depths. The kingdom was shrouded in deep despair, and all sensed its end. Amidst this, a single man quietly enters the guild tavern. His name is Allen. To carve his existence into the world, and to resist the despair overflowing into it, he challenges the depths of the "Abyss."