This story centers on the Dobbs family who lives close to an air force base. The father, "Harry" played by Joe Mantegna, is an overbearing survivalist infatuated with his prospect of surviving a nuclear war.
Harry has built a fallout shelter as he feels that his area would be a primary nuclear target due to its proximity to an Air Force base. Harry's wife gets fed up with his abuse and leaves. While being visited by a friend, an explosion goes off; Harry recognized the precursor blast of an atom bomb and rushes to the shelter along with Nick, his friend. The blast has knocked out communications with the outside world and the pair has to settle down to wait for the radiation levels to go down. A red flashing indicator on the wall will signal when it's safe to come out, which Harry expect to be only a few weeks. Months pass and the constant red flashing light on the wall indicate the radiation has not gone down. Nick cracks and escapes the shelter. Nick attempts to return to the shelter but Harry will not let him in, fearing he has been contaminated. Nick tells Harry that everything is destroyed and oddly enough that the sun never comes out, which Harry interprets as the onset of nuclear winter. Harry is forced to hear Nick in agony as he begs to be let back into the shelter, slowly dying of radiation poisoning at the shelter's door. Several more months pass and Harry is out of supplies and surrounded by accumulated trash, the ominous red flashing light is still there. With his fate sealed, Harry gets his combat gear on and prepares to step outside into the post apocalyptic world. In true Twilight Zone tradition the ending is unexpected yet filled with irony and a bit of poetic justice.
This is my favorite episode of the 1985 series and look forward to owning it on DVD.