An invisible and mysterious force field descends upon a small actual town of Chester's Mill, Maine, USA, trapping residents inside, cut off from the rest of civilization. The trapped townspeople must discover the secrets and purpose of the dome or sphere and its origins, while coming to learn more than they ever knew about each other and animals too.

Barbie's execution is interrupted by the dome, which seems to have become magnetized. Rachel rescues a drowning girl in the lake and is assisted by a former EMT who lives nearby. He thinks he recognizes the girl. Rebecca Pine, a high school teacher, tells Barbie she thinks the dome's electromagnetic force is interfering with people's brain waves causing the hallucinations, seizures and unconsciousness many are suffering from. While Rebecca works on building a magnet to counteract the force, Angie thinks this is happening because they did not kill Big Jim as their vision showed them. Big Jim is trapped in his underground bunker where he has an unexpected visitor. Written by garykmcd

Big Jim seems to have turned over a new leaf, convinced that the dome saved his life. They have an immediate problem when Rebecca determines that the influx of butterflies has led to a massive increase in the caterpillar population with half of their local crops now infested. Rebecca wants to burn half of the crop to save the rest but Big Jim decides that with the infestation the dome is testing him. He has another plan. At the high school, Junior finds Angie's bloodied corpse. They also find a woman's bloody shoe print. Junior thinks his father is responsible but Joe saw him asleep at home. Sam reveals to Julia that his late sister was Big Jim's wife. He also shows her the sketch she made that appears to be the girl Julia rescued from the lake. Written by garykmcd

As resources dwindle, Big Jim holds a census in order to forecast how long Chester's Mill can continue to exist under the dome, while chaos ensues when a rainstorm turns into acid rain. Written by Anonymous

As conditions in Chester's Mill worsen, Big Jim and Rebecca consider resorting to population control, which drives a wedge between Barbie and Julia. Meanwhile, clues to Melanie's past and her connection to the Dome are revealed. Written by Jiilo_Kim

Julia takes over as leader of Chester's Mill after the town becomes divided in the wake of Big Jim and Rebecca's plans for population control. Meanwhile, Joe and Norrie continue to help Melanie search for more clues about her identity. Written by ab1995

Despite Julia's gesture of goodwill, Big Jim is still determined to take charge of his town. Facing a powerful dust storm, Rebecca tells him they need to erect a windmill and spray water into the atmosphere inside the dome. When Big Jim looks for support however, he finds that most have turned against him. Sam, Junior and Barbie set off down the tunnel they've found leading out from under the high school. A explosion leaves Junior on one side of the rock fall. He locates Joe, Norrie and Melanie and tells them of the danger they're in. They head to the lake to try and retrieve the egg. Sam and Barbie meanwhile continue their search down the tunnel and come to a cliff edge with an apparently bottomless abyss below. Barbie soon realizes who is responsible for Angie's death. Written by garykmcd

Junior refuses to believe that his Uncle Sam killed Angie so Sam returns to the tunnels with Julia and Rebecca intent on recovering Sam's body. As he descends into the black void his equipment fails and threatens to drag Julia down with him so he cuts the rope and falls into the abyss. He awakens in a place that he knows well and turns to the one person he knows could likely help him get a message to Julia. Similarly, Sam has survived his fall and tracks down his sister Pauline. Back in Chester's Mills, Julia believes Barbie is dead and doesn't want Big Jim to learn what's happened fearing he will again take over the town. Written by garykmcd

In Zenith, Barbie asks his father to get a message to Julia but learns from a new friend that the message was altered. Barbie also learns that his father's company has been monitoring all activity in the dome for the government - but not necessarily sharing everything they've seen. Meanwhile, Sam and Pauline try an experimental drug on Lyle who manages to come out of his stupor. Back in Chester's Mills, Big Jim makes himself the new sheriff. After someone tears down the windmill and torches a car he sold, he concludes that someone is sending him a message. Written by garykmcd

Barbie finds himself under arrest by unknown men who, not surprisingly, want to know how he got out of the dome. They also want to get their hands on the egg. Pauline, Sam and Lyle try to decipher the meaning of her last postcard - a picture of a red door - and suspect it may be a way back into the dome. They eventually head to Hunter's apartment where they meet up with Barbie who knows exactly where to find it. In Chester's Mills, Big Jim knows that Barbie has got out and presses Junior to tell him what is going on. When he learns about the egg, he tasks Rebecca to find out where it is. Written by garykmcd

Everyone is shocked by the return of Barbie, Sam and Pauline. Big Jim's shock at his wife's return goes from disbelief to anger when he realizes she faked her death. Melanie learns from Sam who her killer was. Sam also confesses to Pauline and Junior about Angie's murder. Julia is relieved by Barbie's return and he fills her in on what's happened to him. He suggests that they give the egg to his father in return for letting everyone leave Chester's Mills. Big Jim has his own plans however - one that leads to disaster. Written by garykmcd

With the portal to get out of the dome now gone - as is the egg - the residents of Chester's Mills face having to deal with frigid temperatures. The clinic has been damaged so all of the sick and those needing shelter move into the school. Meanwhile, Julia has a serious accident and Barbie refuses to leave her behind in the freezing cold. Lyle suddenly reappears. In Zenith, the egg is found in the same park where Barbie and the others arrived when traveling through the portal. Attempts to touch it are having a serious effect on Melanie. Soon, everyone is in danger from the dome. Written by garykmcd

As the temperatures inside the dome return to normal, it continues to retract forcing everyone into the center of the city. Melanie's health continues to deteriorate and it becomes obvious that her condition is directly related to the fate of the egg. Barbie doesn't react well when he learns that Hunter was spying for his father. He gets his father Don the dome's edge, telling him they need the egg to survive. Don agrees but the military intervenes. An attempt to cure Melanie goes horribly wrong. Written by garykmcd

Pauline is dying but Big Jim refuses to accept that possibility. He tries desperately to find something, anything, to save her. When he is unsuccessful, he goes on a rampage. Joe and Norrie explore the new tunnel and think they may have found a new way out from under the dome. Barbie and Julia begin organizing a evacuation of all of the town's residents. Deep in the tunnels they receive help from an unexpected source. Some people are left behind. Written by garykmcd

Under the Dome is the story of a small town that is suddenly and inexplicably sealed off from the rest of the world by an enormous transparent dome. The town's inhabitants must deal with surviving the post-apocalyptic conditions while searching for answers about the dome, where it came from and if and when it will go away. Written by ahmetkozan