When Barbie realises he left his dog tags at the cabin where he killed Julia’s husband Peter, he heads back to retrieve them but is ambushed by Junior who believes Angie is romantically involved with him.

Deputy Paul Denton, who accidentally killed Deputy Freddy, escapes his jail cell by locking Linda inside, Big Jim rescues her and decides to organise a search party to find Paul by recruiting other townsmen and a reluctant Barbie.

After Julia learns that Phil and Barbie are connected to her husband Peter, she questions Phil about Peter’s whereabouts, but he passes out from an unexpected illness. 

As Joe continues his speculation that he and Norrie are human receivers for the dome, they are distracted by a swarm of butterflies by the dome dispersing to reveal a wave of family and friends coming to visit the townspeople.

After the town’s water tower is inadvertently destroyed and the lake is found to be polluted, Barbie helps Linda stop the looting that breaks out in response to the weaning resources.

While experimenting with their effect on the dome, Joe and Norrie find a mysterious mini dome encasing an egg shaped object buried in the center of the town.

With the limited water supply and the threat of a potential food shortage, Big Jim tries unsuccessfully to bargain with Ollie for more water from his well in exchange for propane.

When Big Jim enacts a mandate to collect all of the guns in town, he ends up taking down an unhinged and heavily armed townsperson with Barbie’s help. 

Upon learning of the ambiguous "insurance policy” Max has threatening to expose Big Jim and Barbie, Big Jim goes off in search of leads and comes across an older woman, Agatha, who soon reveals herself as Max’s mother.

When Max shoots Julia in the chest, Barbie’s quick thinking manages to keep her alive in the midst of a storm brewing inside of the dome.

The hunt for Barbie is on as Big Jim steadily gains more control over the townspeople in the dome, who are naively willing to give up their rights in order to feel protected.

In order to buy Julia and the kids more time to do its bidding, the dome covers itself in an opaque, black coating, preventing light from the outside getting in.