Under the Dome Episode Guide

The first season traps Chester’s Mill beneath the dome and watches its social order begin to collapse. As Barbie conceals his connection to Julia’s missing husband, Big Jim Rennie exploits each emergency to strengthen his position and several teenagers discover that the barrier has plans of its own.

Episode 1: Pilot

Skully’s Pick

An enormous transparent barrier suddenly descends around Chester’s Mill, severing roads, communications and the town’s connection with the outside world. Former soldier Dale “Barbie” Barbara becomes involved in the rescue effort while hiding the real reason he was attempting to leave.

Episode 2: The Fire

A house fire threatens to spread through the town while conventional emergency services remain stranded outside the barrier. Big Jim begins managing the crisis, and Barbie realises that Chester’s Mill contains secrets almost as dangerous as the dome.

Episode 3: Manhunt

A deputy escapes custody after a fatal shooting, forcing Linda to organise a search with dangerously limited resources. Junior joins the pursuit while continuing to conceal Angie’s imprisonment beneath his family home.

Episode 4: Outbreak

An outbreak of meningitis overwhelms the clinic and places several central residents at risk. Julia searches for medicine and answers, while Junior’s increasingly erratic behaviour begins attracting attention.

Episode 5: Blue on Blue

The military prepares to strike the dome with an extremely powerful missile, prompting residents to gather near the barrier to say goodbye to loved ones outside. The episode captures the emotional scale of the separation before testing whether the dome can survive humanity’s most forceful response.

Episode 6: The Endless Thirst

A damaged water tower leaves Chester’s Mill facing a rapidly worsening shortage. As shops are looted and tempers erupt, Big Jim negotiates with the one resident who still controls a reliable supply.

Episode 7: Imperfect Circles

Skully’s Pick

Julia helps a woman who goes into labour after touching the dome, while Norrie’s family faces a medical emergency of its own. The contrast between birth and death gives the episode unusual emotional weight as Joe and Norrie make another discovery beneath the town.

Episode 8: Thicker Than Water

Control of Chester’s Mill’s wells leads to an armed confrontation between Big Jim and farmer Ollie Dinsmore. Junior must choose between his father and a man offering him a different account of his mother’s death.

Episode 9: The Fourth Hand

A figure from Barbie and Big Jim’s criminal past arrives with information capable of exposing them both. Joe, Norrie and Angie investigate their connection to the mini-dome and search for the fourth person required to complete its strange pattern.

Episode 10: Let the Games Begin

Barbie is drawn into an underground fight club being used to control Chester’s Mill through violence and debt. Julia follows evidence surrounding Peter’s disappearance, while the teenagers bring the four hands together around the mini-dome.

Episode 11: Speak of the Devil

A violent storm appears to respond to conflict among the four hands, suggesting that their cooperation affects the dome. Barbie and Big Jim attempt to deal with a shared enemy, but Julia is caught in the consequences of their alliance.

Episode 12: Exigent Circumstances

Big Jim uses the local radio station to turn Chester’s Mill against Barbie, blaming him for crimes committed since the dome arrived. With Julia unable to defend him, Barbie’s remaining allies attempt to expose the truth before he is captured.

Episode 13: Curtains

The four hands confront a disturbing vision of what the dome may expect from them. As Big Jim prepares a public execution, the mini-dome hatches and the identity of the promised monarch becomes clear.

The second season introduces science teacher Rebecca Pine, Junior’s uncle Sam and new evidence that the dome’s history began long before its arrival. With supplies failing and the barrier behaving unpredictably, the search for answers leads beneath Chester’s Mill and eventually beyond it.

Episode 1: Heads Will Roll

A powerful magnetic pulse tears through Chester’s Mill and interrupts Barbie’s execution. As the town suffers devastating losses, a mysterious young woman appears and Angie makes a discovery at the school.

Episode 2: Infestation

A caterpillar infestation threatens to destroy Chester’s Mill’s remaining food supply. Rebecca proposes an aerial solution that could save the crops, while Barbie investigates the latest murder inside the dome.

Episode 3: Force Majeure

Blood-red rain falls over the town as an illness begins spreading among the residents. Big Jim conducts a census of Chester’s Mill, and Junior follows a clue suggesting that someone he believed dead may still be alive.

Episode 4: Revelation

Rebecca argues that the town’s dwindling resources require a drastic reduction in population. Julia opposes her plan, while Junior and Sam investigate the connection between Pauline’s drawings and the dome’s arrival.

Episode 5: Reconciliation

Julia attempts to reunite the divided town and organise a fair system for distributing food. Her efforts are threatened by an explosion and growing suspicion surrounding Angie’s death.

Episode 6: In the Dark

A tunnel collapse traps Barbie and Sam beneath the school while a dust storm endangers everyone above ground. Their search for an exit exposes Sam’s connection to the dome and forces him to confront the secrets he has been carrying.

Episode 7: Going Home

Skully’s Pick

Barbie follows Sam into the seemingly bottomless chasm beneath Chester’s Mill. Rather than finding death at the bottom, he awakens somewhere that radically changes what everyone believes about the dome.

Episode 8: Awakening

Outside the barrier, Barbie tries to contact Julia and find a route back into Chester’s Mill. His search brings him to his estranged father and an organisation taking a suspicious interest in the dome’s egg.

Episode 9: The Red Door

Barbie is detained and questioned about the egg, while memories of his childhood reveal a possible path into Chester’s Mill. Pauline, Sam and Lyle attempt to use the same route as the town’s two divided groups work towards a reunion.

Episode 10: The Fall

Barbie returns to Chester’s Mill with unsettling information about the people studying the dome from outside. Melanie’s health begins failing after separation from the egg, and Pauline’s visions point towards a fresh disaster.

Episode 11: Black Ice

A sudden temperature collapse transforms Chester’s Mill into a frozen landscape. Barbie and Julia attempt to rescue stranded residents, while the return of another familiar figure complicates Pauline’s plans.

Episode 12: Turn

The dome begins contracting, placing the entire town under increasing physical pressure. Pauline believes her drawings reveal how to save Melanie, but restoring the connection with the egg requires cooperation from both sides of the barrier.

Episode 13: Go Now

The residents descend into the caves as the shrinking dome threatens Chester’s Mill. Barbie leads the evacuation towards a possible exit, while Julia, Big Jim and Junior face their own crisis above them.

The final season reveals the intelligence operating through the dome and introduces the Kinship, a collective capable of altering memory, loyalty and identity. The result is the programme’s most overtly extraterrestrial season, with former enemies forming an uneasy resistance against a town that no longer behaves like itself.

Episode 1: Move On

Barbie and the residents apparently escape Chester’s Mill and begin rebuilding their lives over the following year. Julia and Big Jim experience a very different reality, suggesting that the apparent freedom contains more than a few suspiciously tidy edges.

Episode 2: But I’m Not

Julia attempts to release the townspeople from the strange cocoons hidden beneath Chester’s Mill. Their awakening introduces Christine and Eva, two unfamiliar women whose connection to the caves and the egg remains unclear.

Episode 3: Redux

The survivors return to town and try to resume ordinary life after their shared experience underground. Big Jim distrusts Christine’s influence, while Barbie struggles to reconcile his feelings for Julia with memories of a life involving Eva.

Episode 4: The Kinship

Christine encourages Chester’s Mill to function as a harmonious collective, but her methods begin eroding individual choice. Julia and Big Jim find themselves in the unlikely position of working together against an enemy most residents cannot recognise.

Episode 5: Alaska

Big Jim investigates Christine’s past and discovers evidence of an earlier expedition connected to the egg. Julia tries to reach Barbie as the Kinship tightens its control and divides the town according to Christine’s needs.

Episode 6: Caged

The Resistance captures Christine and attempts to learn what has happened to Chester’s Mill. Barbie and the Kinship close in on their position, leaving Julia to decide how far she will go to restore the man she knew.

Episode 7: Ejecta

Skully’s Pick

A catastrophic meteor shower strikes the world beyond the dome, apparently leaving Chester’s Mill protected from destruction. The disaster forces both factions to consider the dome’s wider purpose while Julia makes a breakthrough with Barbie.

Episode 8: Breaking Point

The Resistance prepares an assault against Christine’s operations as her plans for Eva and Barbie’s child accelerate. An Aktaion team enters the dome offering scientific expertise, although its leader’s methods create another potential threat.

Episode 9: Plan B

Julia uses an intensely personal strategy to break the Kinship’s hold over Barbie. Meanwhile, Big Jim and Aktaion test a possible cure on infected residents, raising serious questions about how many lives their solution may cost.

Episode 10: Legacy

Aktaion’s true intentions create conflict within the Resistance as the Kinship prepares for the birth of its next leader. Barbie races to protect Eva, but the child developing inside her is no ordinary infant.

Episode 11: Love Is a Battlefield

Barbie and Julia attempt to repair their relationship while the rapidly changing newborn becomes central to the Kinship’s survival. Christine’s authority weakens, allowing another figure to assume control over the collective.

Episode 12: Incandescence

The dome begins turning to stone, threatening to suffocate everyone inside Chester’s Mill. The Resistance and Kinship are forced into a temporary alliance as Joe works on a device capable of bringing down the barrier.

Episode 13: The Enemy Within

Skully’s Pick

Joe’s transmitter offers one final chance to destroy the dome, but activating it demands a severe personal sacrifice. Barbie, Julia and Big Jim confront the Kinship’s new queen as Chester’s Mill reaches the end of its imprisonment.

Under the Dome ends with the barrier removed and the fate of Chester’s Mill largely resolved. Its closing scenes leave one thread deliberately open, but the three-season story has a functional conclusion rather than stopping halfway through the central mystery. Whether the eventual explanation justifies 39 episodes of eggs, monarchs, pink stars and deeply questionable local government is a decision best made outside the dome.