The last survivors of the apocalypse have woken up after two hundred years in cryosleep. The bunker cohorts scattered across the country have different rules, rivalries, and expectations for the future.

Joanna Murphy travels to the Oregon bunker, hoping to forge an alliance between the cohorts. But Oregon is on edge after an attack, and they're in no mood for peace talks.

Charlotte Hartland needs to move her cohort to better land, but her people fear the outside world, and they're questioning her leadership. Joanna's arrival could undo all Charlotte's progress.

When strangers from a third bunker appear, Joanna and Charlotte must work together to combat a startling new threat. If violence breaks out between the cohorts, it could destroy everything they've built.