Three years after emerging from cryosleep, the survivors of the apocalypse don't always agree on the best way to live together. Joanna and Levi travel between the bunker communities, fostering cooperation and trying to prevent conflicts. It's harder than it looks.

Just when Joanna thinks they're making progress, she learns a cohort is missing.

The bunker's nearest neighbors claim the inhabitants never woke up from cryosleep, but they might be lying. Joanna and Levi set out to find the missing cohort and uncover the truth. What they discover could spell disaster for every settlement in the country.

Meanwhile, a young survivor called Kate discovers that her isolated community isn't as idyllic as she thought. She must break free if she has any hope of saving her home.