In the aftermath of global nuclear annihilation, a fractured detachment of the Brotherhood of Steel finds itself stranded across the Midwest when catastrophic storms cripple their aerial fleet. The survivors establish a foothold near Chicago's devastated remains and forge an unconventional new order, breaking with tradition by incorporating capable wasteland tribes into their military structure. Players assume the role of a fledgling Brotherhood recruit thrust into squad leadership and tasked with pacifying the hostile wasteland surrounding their settlement, engaging raiders and emerging dangers as the faction attempts to assert control over the region's lawless territories.