An eight-wheeled vehicle trundles across a barren landscape of ash and ruined buildings toward a lone bunker deep in the wilderness. Inside the vehicle are three passengers: two scientists—who plan to use the outpost as a home base for the study of world-ending phenomena—and a boy named Charlie. As the work unfolds, the isolation and claustrophobia of the compound threatens each member of the expedition with madness. Forced to confront their own dark history and the struggles of the haves and have-nots, the members of the expedition find themselves hurtling toward ruin.