Blue on Blue (Under the Dome)

Despite finding Angie in the shelter, Jim leaves her locked up, unable to believe his son would do such a thing. Meanwhile, the military has scheduled a "visitors' day" for the residents of Chester's Mill, where family members and friends of people trapped in the dome can come and visit their loved ones. During the event, Linda tells her fiancé about his brother's death, Norrie meets her estranged biological father (Gary Weeks), who her parents had led her to believe she would never be able to find, and Barbie finds out from a soldier stationed outside the dome that the military plans to attempt to destroy the dome with a missile (MOAB), which will likely kill everyone inside. When Barbie relays this to Big Jim, he orders everyone to take shelter in the tunnels underneath the city. He then releases Angie from her captivity, but when Junior finds out, he sets off after her while everyone else takes shelter in the tunnels.

As most of the town prepares for the inevitable in the tunnels, Joe and Norrie search for Angie, Junior finds Angie at her house and they spend what they believe will be their last moments together, and Barbie and Julia search for Norrie at the request of her parents. As the missile approaches, Norrie and Joe share a kiss.

The missile harmlessly impacts the dome, laying waste to everything outside of it but leaving the town unscathed. Norrie and Joe find that they no longer have seizures when they touch. As Big Jim investigates the edge of the dome, he is approached by Reverend Coggins, who earlier gave him an ultimatum to admit his part in a drug scandal to the town. Jim kills Coggins by pressing his head against the dome, causing his hearing aid to explode.

American journalist Jeff Glor played himself in this episode.[6] Brian K. Vaughan teased the plot of the episode via an interview with The Hollywood Reporter, saying "I don't want to spoil too much about the military's plan, but I can say next week's episode begins with a "visitors' day." It's finally a chance for the people trapped inside Chester's Mill, inside the dome, to talk with not just their loved ones but the rest of the free world—what's going on, to get more information about this, if there are any more domes around the world. So far, they've been entirely cut off from the world, but now they'll start getting big answers."[7]

Dean Norris said in an interview with Zap2it regarding the dome "there's a lot more understanding of what it is, and that's part of the story that also starts really picking up in [episode 5], and really accelerates through to the end of the season, where the dome becomes a real character and the kids actually start to understand it."[8]