Day the World Ended

Day the World Ended

Year: 1955

Runtime: 79 mins

Language: English

HorrorScience FictionMonsters aliens sci-fi and the apocalypseHorror the undead and monster classicsDangerous technology and the apocalypse

After a nuclear strike, a mismatched band of survivors—a geologist, a petty thief with his companion, and a prospector—take refuge in a remote valley house owned by a rugged survivalist and his attractive daughter. Their safety is shattered when they are beset by a hellish creature and must confront spreading radiation and its deadly impact on wildlife and humanity.

Warning: spoilers below!

Haven’t seen Day the World Ended yet? This summary contains major spoilers. Bookmark the page, watch the movie, and come back for the full breakdown. If you're ready, scroll on and relive the story!

Day the World Ended (1955) – Full Plot Summary & Ending Explained

Read the complete plot breakdown of Day the World Ended (1955), including all key story events, major twists, and the ending explained in detail. Discover what really happened—and what it all means.

In a world shattered by an atomic war, a small, pristine refuge survives where Earth remains tainted by radioactive fallout. Jim Madison Paul Birch is a former U.S. Navy commander who has carved out a fragile life with his daughter Louise Madison Lori Nelson inside a sealed box canyon, surrounded by lead cliffs and stocked with supplies he carefully hoarded for a crisis like this. Louise is preparing for a future with her fiancé, but that man has vanished, leaving only a photo on her nightstand. The photo is of Nelson Roger Corman, a reminder of a promise that may never come true.

One day, a handful of survivors stumble into the canyon, drawn by chance to Jim’s shelter as the world outside remains hazardous. Among them is Rick Richard Denning, a geologist who specializes in uranium mining, who understands the precious, precarious nature of their new home. Also present are Tony Lamont Mike Connors and his moll Ruby Adele Jergens, two travelers bound for San Francisco, and a Contaminated Man Jonathan Haze, a figure who embodies the danger of the irradiated landscape. Jim is initially wary, but his humanity proves stronger than suspicion, and he slowly grants them shelter.

Two threats loom over this fragile existence. The first is the simple and urgent question of whether the radioactive fallout will ever dissipate, and whether any rain will come that could wash the poison from the air and soil before it corrodes everything inside the canyon. The second is a more immediate, fearsome danger: a hideous atomic-mutated monster, a creature that hunts and kills among those whose flesh carries the taint of fallout. The Mutant [Paul Blaisdell], a figure both grotesque and terrifying, testifies to the brutal rules of this new world.

Beneath the surface, a darker danger simmers. Tony, outwardly charming and helpful, harbors a selfish plan: he wants to remove the other men from the picture so he can pursue Louise for himself. His true nature begins to reveal itself, and the fragile trust among the survivors is strained to the breaking point. When the monster strikes, it kidnaps Louise, forcing a dramatic confrontation between fear, loyalty, and survival.

Louise escapes by fleeing into a small freshwater lake, where the creature hesitates to follow. Rick confronts the Mutant in a tense sequence, and the monster retreats as rain begins to fall. The rain proves lethal to the creature, dying as the storm intensifies and the cooling water erases the contamination that gave the beast its power. In the aftermath, Louise is rescued by Rick, and their bond deepens as the skies clear of danger. Meanwhile, Tony’s treachery comes to a brutal end: Jim, who has been slowly dying from radiation poisoning, reveals a crucial truth to his rescuers—that the rain is radiation-free and will wash away the remaining contamination, opening the path to a safer world beyond the canyon. In his final moments, Jim also confirms that he has heard voices of other survivors on the radio, hinting at a larger world still alive.

When the rain finally ceases, Rick [Richard Denning] and Louise [Lori Nelson] walk hand in hand out of the canyon, stepping toward a future that holds the possibility of beginning anew. The frame lingers on the quiet landscape as the end card proclaims “The Beginning,” signaling not an ending but the chance to reclaim life beyond the shelter.

Last Updated: October 09, 2025 at 11:01

Mobile App Preview

Coming soon on iOS and Android

The Plot Explained Mobile App

From blockbusters to hidden gems — dive into movie stories anytime, anywhere. Save your favorites, discover plots faster, and never miss a twist again.

Sign up to be the first to know when we launch. Your email stays private — always.

Unlock the Full Story of Day the World Ended

Don't stop at just watching — explore Day the World Ended in full detail. From the complete plot summary and scene-by-scene timeline to character breakdowns, thematic analysis, and a deep dive into the ending — every page helps you truly understand what Day the World Ended is all about. Plus, discover what's next after the movie.

Day the World Ended Timeline

Track the full timeline of Day the World Ended with every major event arranged chronologically. Perfect for decoding non-linear storytelling, flashbacks, or parallel narratives with a clear scene-by-scene breakdown.

Day the World Ended Timeline

Characters, Settings & Themes in Day the World Ended

Discover the characters, locations, and core themes that shape Day the World Ended. Get insights into symbolic elements, setting significance, and deeper narrative meaning — ideal for thematic analysis and movie breakdowns.

Characters, Settings & Themes in Day the World Ended

More About Day the World Ended

Visit What's After the Movie to explore more about Day the World Ended: box office results, cast and crew info, production details, post-credit scenes, and external links — all in one place for movie fans and researchers.

More About Day the World Ended