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Them! Plot Summary

Read the complete plot summary and ending explained for Them! (1954). From turning points to emotional moments, uncover what really happened and why it matters.


In 1954, a calm desert morning turns into a chilling investigation when two New Mexico State Police officers come upon a little girl wandering in a catatonic state near Alamogordo, closely followed by a ravaged travel trailer and a dead, mutilated owner in the nearby cellar. The scene is grim and puzzling: no money has been taken, yet violence and ruin are everywhere. As the officers process the sites, they notice a pulsing, ominous sound outside, and one of them, left alone to wait for backup, fires his weapon in a desperate moment of terror.

An FBI agent arrives to help piece together the mystery. He sends a sample of a trench coat-like cast from the trailer’s vicinity to Washington, D.C., only to be met with an unusual response: Drs. Harold and Pat Medford—a father-and-daughter duo renowned for their work with ants—are dispatched by the Department of Agriculture. On a hunch, Harold tests the little girl with the scent of formic acid, a chemical signature of ants. The effect is dramatic: the girl breaks from her catatonia in a scream of fear, crying, “Them! Them!”

The investigators, accompanied by the Medfords, re-trace the crime scene. During the search, Pat is charged by a giant foraging ant, and Harold directs the team to shoot off the creature’s antennae to blind it, while a Thompson submachine gun finishes the strike. Harold theorizes that radiation from the first atomic bomb tests near Alamogordo has mutated the ants, driving them to carnivory due to the desert’s sparse food supply.

A helicopter sweep of the desert uncovers a massive ant nest, ringed with human remains. Cyanide gas bombs are deployed, and the trio presses inward. They meet a pair of surviving guard ants, eliminated with a flamethrower and the trusty Thompson. At the lowest levels, they discover evidence that two queen ants have hatched and flown away. Harold cautions that if the queens establish new colonies, humanity could lose its position as the top species within a year.

To keep the threat under wraps and prevent widespread panic, the operation widens in secrecy. Graham and Pat travel to Brownsville, Texas, to question a ranch foreman who was committed to a mental hospital after claiming he’d been forced down by UFOs shaped like giant ants. The hunt continues as one ant queen boards a freighter in Acapulco; its offspring surface in the Pacific and terrorize the crew, with the Navy sinking the ship after two sailors survive.

A report about a stolen sugar shipment leads investigators to a Los Angeles hospital, where a chronic alcoholic swears he has seen giant ants in the city’s storm drains. Tracing a man whose mutilated body was found in the area uncovers another giant ant print, and the team becomes convinced that the final missing queen—and the two missing young sons—are somewhere within the sprawling, subterranean tunnels beneath the city, an underground world spanning more than 700 miles.

Martial law grips Los Angeles, and a curfew is imposed as the search intensifies through the drain network. Peterson locates the two boys, trapped by the advancing insects, and, with a last-ditch surge of reinforcements, pulls them to safety. Graham arrives just in time to confront the ominous queen and her hatchlings, and the Medfords verify that no new queens have escaped. The order is given to destroy the nest, ending the immediate threat but leaving a haunting question in the air: what havoc might follow the other nuclear explosions of the era? Harold answers with a grim, forward-looking honesty: mankind has entered a new world, and no one can predict what we will find.

Them! Them!

Them! Timeline

Follow the complete movie timeline of Them! (1954) with every major event in chronological order. Great for understanding complex plots and story progression.


Discovery of the catatonic girl in the desert

Two officers find a catatonic girl wandering the desert near Alamogordo, along with the ravaged travel trailer she came from. They call for an ambulance and begin processing the crime scene. The discovery hints at a larger, more dangerous mystery at work.

1954 Alamogordo, New Mexico

Destruction at the general store

The investigators head to a nearby rural general store, which has been destroyed in the same manner as the trailer. The store owner's body is found in the cellar, mutilated, and clearly not a robbery. No money is missing from either scene, suggesting something beyond ordinary crime.

1954 Near Alamogordo, New Mexico

An ominous sound and attack

Back at the trailer site, Blackburn hears a strange pulsating sound from outside and investigates. He fires at something unseen and experiences a painful, violent shock, screaming in agony. The incident implies a deadly, otherworldly threat at the crime scene.

1954 Desert near the trailer, Alamogordo area

Graham arrives; scientists are summoned

Agent Robert Graham is called in from the local FBI office to assist Peterson. He forwards a footprint cast to Washington, D.C., and learns that Drs. Harold and Pat Medford, a father-daughter myrmecology team, are being sent by the Department of Agriculture. Their expertise will help identify the insect clue.

1954 Alamogordo / local FBI office

Formic acid triggers a reaction

Harold Medford exposes the girl to the scent of formic acid, a chemical characteristic of ants. The odor jolts her from catatonia, but she screams 'Them! Them!' in panic. The scientists begin to connect the girl’s condition to an ant-related threat.

1954 Field near the trailer, desert

Ant attack and blinding a threat

Pat Medford is attacked by a giant foraging ant during a field search. Harold directs Peterson and Graham to shoot off the ant's antennae to blind it, then Peterson finishes the creature with a Thompson submachine gun. The encounter demonstrates the ants' dangerous capabilities.

1954 Desert search area

Mutation theory and the nest found

Harold theorizes the ants were mutated by radiation from the first atomic bomb test near Alamogordo and have become carnivorous due to desert scarcity. A helicopter discovers a giant nest surrounded by human remains. Cyanide gas bombs are dropped and Graham, Peterson, and Pat enter to explore the nest.

1954 Desert, near Alamogordo

Two queens hatch and threaten spread

At the lowest level, Pat finds evidence that two queen ants have hatched and flown away, suggesting the potential for further outbreaks. The team realizes the danger of rapid spread if the queens establish new colonies. Harold warns that humanity could be displaced if the ants proliferate.

1954 Ant nest; desert

Widening search: Brownsville lead

The search area broadens as investigators pursue leads across states. Graham and Pat travel to Brownsville, Texas, to interrogate a ranch foreman who claims he was forced down by UFOs shaped like giant ants. The information expands the scope and urgency of the investigation.

1954 Brownsville, Texas

Acapulco freighter incident

A queen ant boards a freighter in Acapulco, and its offspring emerge in the Pacific. The U.S. Navy responds but only finds two sailors alive; the freighter is ordered sunk to prevent spread. The pursuit of the ants reaches transoceanic scales.

1954 Acapulco / Pacific Ocean

Los Angeles drains: a citywide threat

A shipment of stolen sugar leads investigators to a Los Angeles hospital, where a chronic alcoholic claims to have seen giant ants in the city’s storm drains. They trace the sightings to the drain network and connect them to the missing queen and two missing boys.

1954 Los Angeles, California

Martial law and the drain sweep

Martial law is declared in Los Angeles and a curfew is imposed as the armed forces and scientists search the 700 miles of tunnels beneath the city. The team locates the remaining queen and confirms no other queens have escaped. The scale of the threat becomes starkly clear.

1954 Los Angeles drains

Rescue and final confrontation

Peterson finds the two missing boys trapped by ants and calls for reinforcements. He is killed during the rescue attempt, but Graham arrives with backup and the queen along with her hatchlings is located. The nest is destroyed in a final push to end the invasion.

1954 Los Angeles drainage system

Endgame and reflection

The Medfords confirm no further queens remain and the nest is destroyed, marking a grim victory. Graham wonders what havoc past nuclear explosions might unleash, and Harold notes that humanity has entered a new world with an unpredictable future.

1954 Los Angeles

Them! Characters

Explore all characters from Them! (1954). Get detailed profiles with their roles, arcs, and key relationships explained.


Robert Graham (James Whitmore)

An FBI agent who coordinates the national investigation. He relies on scientific experts and disciplined planning to trace the ants’ origins and coordinate the response. He represents rational leadership in a moment of escalating peril.

🧭 Investigator 🧠 Logical 🕵️‍♂️ FBI

Harold Medford (Edmund Gwenn)

A renowned myrmecologist who theorizes the ants were mutated by radiation. He leads field analysis and explains how ant behavior could threaten human civilization. His expertise anchors the scientific approach to stopping the invasion.

🧠 Scientist 🧪 Ant expert 🔬 Researcher

Pat Medford (Joan Weldon)

Daughter of Harold, a young scientist who assists in the field and provides practical insight into the ants’ biology. She helps interpret evidence and supports the effort to eliminate the nest.

🧬 Scientist 🧭 Assistant 🌐 Researcher

Ben Peterson (Onslow Stevens)

New Mexico State Police sergeant who leads ground operations and coordinates with federal investigators. He embodies determined leadership and personal sacrifice in the push to save civilians.

🧭 Police officer 🧠 Courage 🏜️ Desert

Ed Blackburn (Sean McClory)

Peterson’s partner who is left to wait for backup and is killed during the encounter with a giant ant. His death underscores the ever-present danger and the price of investigative work.

🧭 Partner 🔫 Field Agent ⚠️ Risk

Little Girl (Sandy Descher)

A catatonic girl found in the desert who awakens to the reality of the threat and helps to propel the investigation. Her presence anchors the human stakes of the crisis.

👧 Child 🧠 Catalyst 🫗 Vulnerable

Them! Settings

Learn where and when Them! (1954) takes place. Explore the film’s settings, era, and how they shape the narrative.


Time period

1954

The events unfold in 1954, in the early Cold War and the dawn of the atomic age. The era's anxiety about radiation, nuclear weapons, and government secrecy shapes how investigators respond. The timeline tightens as the threat to humanity appears imminent.

Location

New Mexico desert near Alamogordo, Los Angeles sewer drains, Brownsville Texas, Acapulco Mexico, Pacific Ocean

The story begins in the New Mexico desert near Alamogordo, where a catatonic girl and a destroyed trailer signal a mysterious threat. The investigation then moves to the desert's edge and into urban environments, including Los Angeles' vast drainage system and a coastal ship in the Pacific. The varied locations emphasize the spread of the danger from remote wastes to populated areas.

🏜️ Desert 🏙️ Urban 🌊 Ocean 🗺️ United States

Them! Themes

Discover the main themes in Them! (1954). Analyze the deeper meanings, emotional layers, and social commentary behind the film.


🧬

Mutation

The film centers on how radiation from atomic testing mutates ordinary desert life into deadly predators. The ants’ growth and carnivorous behavior symbolize the unpredictable consequences of scientific advancement. It uses the mutated insects to explore fear of the unknown at the core of the era.

🛡️

Containment

Authorities seal off areas and restrict information to prevent public panic. Martial law is declared in Los Angeles, and a massive search operation is organized to control the threat. The film questions whether secrecy is effective or ethical when facing existential danger.

🌍

Survival

Humanity confronts a civilization-threatening menace that could outlast the nuclear era’s impacts. The characters’ sacrifices reveal how society prioritizes children’s safety and collective survival over individual safety. The story emphasizes resilience and the fragile balance between civilization and nature.

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Them! Spoiler-Free Summary

Discover the spoiler-free summary of Them! (1954). Get a concise overview without any spoilers.


In a sun‑scorched stretch of 1950s America, a whispered promise of a life‑changing experience sweeps through small towns and lonely outposts alike. The allure is presented as a subtle, almost spiritual breakthrough—something that will lift the weary, rewrite the ordinary, and grant a glimpse of a brighter, more purposeful future. This promise glitters against a backdrop of post‑war optimism, yet an undercurrent of unease pulses through the desert air, hinting that the path to transformation may lead far beyond what anyone anticipated.

The group drawn to this vision is as diverse as the landscape itself: farmers yearning for renewal, veterans haunted by duty, and curious wanderers seeking meaning. Their collective hope is the film’s quiet engine, a shared conviction that an extraordinary encounter will finally justify their sacrifices. The world they inhabit feels both familiar and alien, a place where the ordinary routine of daily life collides with the tantalizing possibility of something beyond the known, whispering of hidden forces that have yet to reveal their true nature.

At the center of this gathering stands Daniel, a man whose cautious optimism masks a deeper yearning for purpose. His initial enthusiasm is contagiously sincere, and he becomes an informal anchor for those around him, embodying the very hopes that have been promised. As the experience unfolds, Daniel is compelled to question the very foundations of his belief system, confronting unsettling insights that threaten to dismantle the comfortable narratives he has built.

The film balances a measured, almost reverent tone with a creeping sense of dread, allowing the audience to feel the magnetic pull of the unknown while subtle shadows lengthen around each character’s resolve. It invites viewers to linger in the tension between expectation and reality, to wonder whether the true transformation lies in the external promise or in the internal revelations that arise when that promise proves far stranger than imagined.

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