The people of Chester's Mill panicked state when a meningitis outbreak hits the community, threatening the already scarce supply of drugs. Meanwhile, Julia continues to seek answers to her husband's disappearance

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.