The residents of Chester's Mill find themselves trapped under an enormous, transparent dome. Panic escalates as resources dwindle rapidly.

Following Duke's death, his house catches fire, forcing the town to rally together to form a bucket brigade. Elsewhere, Junior ambushes Barbie, while Dodee and Phil pick up a military frequency.

When a former deputy goes rogue, Big Jim recruits Barbie to join the manhunt to keep the town safe. Meanwhile, Junior is determined to escape the Dome by going underground.

The Chester's Mill residents receive an unexpected visit from their loved ones on the other side. Meanwhile, the community braces for a threat from outside the Dome.

When the town begins to run low on water, the residents of Chester's Mill begin to fight for the remaining resources. Meanwhile, Julia discovers a strange connection that two of the town's residents have with the Dome.