In the 21st century, catastrophic resource depletion and runaway population growth pushed humanity underground. Millions relocated to vast subterranean facilities sustained by cultivated ecosystems, while the Watchdog enforced brutal order on those left behind on the surface. Decades later, the Earth has recovered enough for the first wave of resettlement to begin. Players take on the role of Jill, a botanist extracted from a Watchdog police state and placed on a team coordinating the return of millions to the surface — a mission that will prove far more complicated than anyone anticipated.