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

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

Big Jim takes matters into his own hands when he feels his authority slipping away, and the Dome displays its power when a life is taken just as a newborn arrives.

Julia uncovers the truth about her husband's disappearance and unravels some of Chester's Mill's darkest secrets. Meanwhile, Maxine shows Barbie how she plans to take control of the town.

Secrets of the Dome are revealed and Big Jim is determined to put an end to Barbie once and for all. Meanwhile, Junior, Angie, Joe and Norrie discover who the Monarch is after receiving a shocking visit from a familiar face.