Episode 1
Barbie's life is in Big Jim's hands; the dome becomes magnetized; Julia tries to save the life of a mysterious girl who may have clues about the origin of the dome.
Episode 2
When Rebecca discovers an infestation of butterfly eggs on the crops, Barbie risks his life to help her save the town's food supply.
Episode 3
Big Jim conducts a census to see how long the town can survive on dwindling resources; acid rain threatens everyone.
Episode 4
Rebecca and Big Jim consider extreme measures as the conditions worsen in Chester's Mill; clues about Melanie's connection to the dome are revealed.
Episode 5
After Big Jim and Rebecca's plan left the town divided, Julia takes over as the leader of Chester's Mill; Norrie and Joe help Melanie find more clues.
Episode 6
A cave-in severs Barbie and Sam's path back to Chester's Mill during their investigation of a mysterious tunnel; a dust storm rages through the town, as Big Jim and Julia face off in a power struggle.
Episode 7
As Barbie descends further into the mysterious tunnel in hope of finding Sam, he comes across a world filled with unanswered questions.
Episode 8
Barbie turns to his father for help contacting Julia but realizes that he may not be trustworthy; Big Jim declares himself sheriff of Chester's Mill.
Episode 9
Barbie is apprehended by mysterious men and relentlessly interrogated about the Dome; Big Jim forms a deal that could permanently seal the fate of the Chester's Mill residents.
Episode 10
Big Jim finally learns what happened to his wife, Pauline; Chester's Mill faces a new threat -- climate change.
Episode 11
Rebecca and Sam try to save Chester's Mill residents as temperatures plunge; Barbie puts his life at risk to help Julia after a terrible accident.
Episode 12
The latest threat intensifies, leaving Chester's Mill residents at risk of being crushed to death; Melanie's health declines as the egg's fate remains uncertain.
Episode 13
Just as the walls start to close in on those trapped in Chester's Mill, a possible exit from the dome is revealed.
