On the remote island of Talrega, the Yggdrasil Labyrinth — a colossal shifting maze carved from the petrified roots of the World Tree — has drawn adventurers for generations with promises of lost technology and legendary treasure. None who entered its deepest strata ever returned. Nyx joins the island's guild to find her sister Aimée, a veteran delver who disappeared inside. Stranded in the abyss after a catastrophic sandstorm, Nyx discovers Olympia — a dormant android carrying fragmented memories of the labyrinth's true function: a containment vault for Jormungandr, a world-devouring corruption born from an ancient failed project to save humanity. As Nyx and her companions descend deeper, the labyrinth's final secret forces a choice that cannot be undone.