Jim Bloggs and his wife Hilda Bloggs are an aging couple living in an isolated cottage in rural Sussex. In the quiet, sunlit rooms they go about small rituals of daily life while Jim reads the newspapers in search of any clue about the deteriorating international situation surrounding the Soviet–Afghan War. The looming threat of a nuclear confrontation casts a pale shadow over their routine, and a radio news report intensifies the tension, suggesting that a war may be only days away. Following the government-issued Protect and Survive pamphlets, Jim constructs a basic fallout shelter, sealing windows with white paint and laying out sacks to lie in when a strike hits. Despite their nerves, the couple clings to a stubborn belief that they can endure, much as they did during the Second World War, and that a Soviet defeat will come.
As a radio transmission warns of an imminent ICBM strike, the couple dash to their shelter and narrowly escape the distant shock waves that batter their home. When they finally emerge after a few nights, they discover that all utilities, services, and communications are destroyed. Jim struggles to understand why nothing functions, assuming the disruptions are temporary wartime measures. The two attempt to resume a semblance of normal life: they brew tea and cook meals on a camping stove, tally the errands they will run once the crisis passes, and try to refresh their dwindling water supply with rainwater. Fallout dust fills the air inside the house, and the sun is muted by radioactive ash and heavy fog outside. Despite the bleak surroundings, they remain hopeful that rescue crews will arrive, maintaining a stoic rhythm as they navigate the new, ruined world.
Outside, they witness a landscape transformed by catastrophe: ash and smoke blot the sky, animals lie dead, buildings lie scorched, and vegetation withers. Their initial optimism gives way to the harsh realities of isolation, the scarcity of food and water, the creeping effects of radiation sickness, and a total absence of contact from authorities. Jim frets over a possible Soviet invasion and even experiences a troubling vision of a Soviet soldier entering their home. Hilda’s health deteriorates rapidly—she endures a traumatizing encounter with a rat in the dried toilet, and her symptoms worsen to include bloody diarrhea and bleeding gums—deepening her sense of despair. Jim clings to the tiny, fragile thread of hope that emergency services will arrive, but night after night passes without help.
As illness tightens its grip, the Bloggs become practically bedridden. Hilda’s hair begins to fall, and the couple’s morale sinks ever lower. Near the end, Hilda suggests they lie down in the paper sacks, and Jim, now resigned, agrees. He attempts to comfort her with prayers, but begins to recite The Charge of the Light Brigade instead, whose militaristic cadence unsettles his weary companion. Hilda weakly pleads for him to stop, and Jim’s voice slowly falters as he finishes the final line, “…rode the Six Hundred…” The countryside outside continues to look unrecognizable as the emergency they hoped for never arrives.
Then, a final shift occurs: the smoke and ash begin to clear, and a pale sun rises through the lingering gloom. The film closes on this quiet, uneasy note, as the credits end with a stark Morse code tapping out the word MAD — mutual assured destruction — leaving the viewer with a stark meditation on the fragility of life in the shadow of nuclear annihilation.
