One year after the dome disappears, Barbie, Joe, and the other townspeople gather for a memorial. Meanwhile, a year earlier, Julia and Junior try to rescue Barbie and the others, but run afoul of Big Jim.
Barbie investigates Ben's claim that something strange is going on in Chester's Mill, but Eva surprises him with unexpected news. Meanwhile, Norrie and Hunter grow closer, and Christine advises Joe to move on.
In the aftermath of the townspeople's experiences in the other reality, people begin acting strangely and Big Jim suspects that something has fundamentally changed the others. Meanwhile, the person responsible sends Melanie to kill Julia.
-- Do You Wanna Dance?
While Christine "guides" the townspeople in rebuilding their homes and finding food, Big Jim is abducted by an Aktaion research team. Meanwhile, Julia and Barbie have a falling out and Julia goes to Bird Island, and Norrie begins reverting to her old self.
Christine sways Eva back to her side with Junior's help, and takes steps against those resisting her attempts to bind the townspeople into a kinship. Meanwhile, Big Jim convinces Julia to help him recover the camera showing that Christine is possessed by the alien life force.
While Christine tries to convince Big Jim to help her escape Aktaion, Julia tries to convince Barbie that Christine and Eva aren't what they seem. Meanwhile, Joe and Norrie rescue hunter when the Kinship prepares to kill him now that he is crippled and a drain on their resources.
A meteor storm comes down outside of the dome, leaving the people of Chester's Mill to contemplate what to do next... and how to fight the Kinship.
While Joe and Norrie search Christine's office for the crystal schematic, Big Jim and Julia try to blow up the cavern holding the crystals. Meanwhile, Eva, sways Barbie to the Kinship.
While Julia and a reluctant Big Jim try to free Barbie from the Kinship, Joe and Norrie meet Sam and bring him back to their current refuge. Meanwhile, Christine prepares for Eva to give birth to the Kinship's new queen.
Hektor brings a team into the dome and meets with the resistance. Meanwhile, Barbie goes back to the Kinship undercover, and Joe decides to help them find a way to bring down the dome and save everyone before it suffocates them.
While Big Jim agrees to let Hektor administer the cure to a captive Junior, Barbie tries to convince Eva to leave the dome with him and their child. Meanwhile, Christine convinces Joe to willingly help them bring down the dome before their enemies arrive,
When the Dome's calcification process accelerates, Chester's Mill has 24 hours before the barrier's breakdown will suffocate everyone inside. While the new deadline puts added pressure on Joe to bring the Dome down, Barbie and Julia race to save his child from The Kinship. Also, Big Jim tries to manage the increasingly volatile Hektor, who is adamant that infected townspeople never escape the Dome.