Things come to a head when a traitor is revealed. One of the group makes a sacrifice as more secrets about the explosion are brought to light.

Barrett and Grover discover a disturbing conspiracy. Those trapped in the fallout shelter might have found an escape route.

The arrival of someone at the school may represent new hope for the group. Grover decides if he can trust Violet with his secret.

As suspicions amongst the survivors grow, one member of the group goes rogue. Grover unintentionally reveals a secret and Violet feels betrayed.

Everyone's suspicious of the newcomers, especially after weapons start to go missing. Ollie and Anka try to bribe everyone with an unusual plan to get out of the valley.

The group struggles with their shocking new reality. Grover returns with a new group of survivors to Barrett’s dismay.

A group of teenagers gather at their high school for Saturday detention, only to be trapped inside when the chemical plant in their small town explodes.

The group tends to their sick classmates, but they soon discover that the peculiar illness is more than meets the eye.

A new deadly threat turns the survivors against each other. Barrett suggests an unpopular way to gather more information on the freaks.

Lashawn is acting strangely, and the kids begin to suspect he might be infected. Zoe and Barrett strike an uneasy alliance.

Grover fights to protect Mary. Diesel and Natalie share a secret. Barrett works to contact the outside world.

Running low on resources, Violet and Zoe take on a dangerous mission. Zoe and Natalie address their past.