In Phoenix, Arizona in late 1959, real estate secretary Marion Crane steals $40,000 in cash from her employer after hearing her boyfriend, Sam Loomis, complain that his debts are delaying their marriage. She sets off to drive to Sam's home in the town of Fairvale, California, switching cars in Bakersfield after an encounter with a suspicious policeman. A rainstorm forces Marion to stop at the secluded Bates Motel a few miles from Fairvale. Norman Bates, the proprietor, whose Second Empire style house overlooks the motel, registers Marion (who uses an alias) and invites her to dinner with him in the motel's office. When Norman returns to his house to retrieve the food, Marion overhears him arguing with his mother about his desire to dine with Marion. After returning, he discusses his hobby as a taxidermist, his mother's "illness" and how people have a "private trap" they want to escape. When Marion suggests that Norman should have his mother institutionalized, he becomes offended and insists that she is harmless. Marion decides to drive back to Phoenix in the morning to return the stolen money. As she showers, a shadowy figure enters the bathroom with a kitchen knife and stabs her to death. Shortly afterward, Norman is heard horrified at his mother's actions and rushes back to find Marion dead. He hurriedly cleans up the murder scene and places Marion's body, her belongings, and, unbeknownst to him, the hidden cash in her car, before sinking the vehicle in a swamp. Marion's sister, Lila, arrives in Fairvale a week later, tells Sam about the theft and demands information about Marion's whereabouts. He denies knowing anything about Marion's disappearance. Arbogast, a private investigator, approaches them, stating that he has been hired to retrieve the money. He stops in at the Bates Motel and questions Norman, whose nervous conduct, stuttering, and inconsistent answers arouse his suspicion. Arbogast examines the guest register and discovers from some handwriting in it that Marion spent a night in the motel. When Arbogast infers from things Norman says that Marion had spoken to his mother, Arbogast asks to speak to her, but Norman refuses to allow it. Arbogast leaves and calls Lila to tell her of his suspicions and that he will return to the motel, speak to Norman's mother, and rejoin Lila in town later. When Arbogast returns and enters the Bates' house to search for Norman's mother, a shadowy figure at the top of the stairs stabs him to death. When Sam and Lila do not hear back from Arbogast, Sam goes to the motel to look for him. Sam spots a silhouette in the house who he assumes is Norman's mother, who is unresponsive to Sam's calls. Lila and Sam alert the local sheriff, Al Chambers, who tells them Norman's mother died in a murder–suicide by strychnine poisoning ten years before. Chambers suggests that Arbogast lied to Sam and Lila so he could pursue Marion and the money. Convinced that something happened to Arbogast, Lila and Sam drive to the motel and check in. Sam distracts Norman in the office while Lila sneaks into the Bates' house. Suspicious, Norman knocks Sam out. As Norman heads to the house, Lila hides in the fruit cellar and discovers the mummified body of Norman's mother. Lila screams in horror, and Norman, wearing women's clothes and a wig, enters the cellar and attempts to attack her, only to be subdued by a recovered Sam. At the police station, a psychiatrist explains to Lila, Sam, and Chambers that Norman killed his mother and her lover out of jealousy. Unable to bear the guilt, he stole his mother's corpse and treated it as if she were still alive, then re-created his mother as an alternate personality, as jealous and possessive toward Norman as he felt about his mother. Whenever Norman was attracted to a woman, "Mother" would take over. Under the "Mother" personality, Norman killed two women before he killed Marion and Arbogast. The psychiatrist concludes that "Mother" has now completely submerged Norman's personality. Norman sits in a jail cell and hears his mother's voice stating the murders were his doing. Marion's car is towed from the swamp.

A deep-space salvage crew find an escape shuttle where Ellen Ripley has been in stasis for 57 years after destroying her ship, the Nostromo, to kill an alien creature that slaughtered the crew. Ripley is debriefed by her Weyland-Yutani Corporation employers who doubt her claim about alien eggs in a derelict ship on the exomoon LV-426, now the site of a terraforming colony. After contact is lost with the colony, Weyland-Yutani representative Carter Burke and Colonial Marine Lieutenant Gorman ask Ripley to accompany them to investigate. Still traumatized by her alien encounter, she agrees on the condition that they exterminate the creatures. Ripley meets the Colonial Marines aboard the spaceship Sulaco but distrusts their android, Bishop, because the Nostromo ' s android, Ash, betrayed its crew to protect the alien on company orders. A dropship lands the crew on LV-426, where they find the battle-ravaged colony and two live alien facehuggers in containment tanks. The only colonist found is a traumatized young girl nicknamed Newt. The team locates the other colonists' signals beneath the fusion-powered atmosphere processing station and heads to their location, descending into corridors covered in alien secretions. At the station's center, the marines discover opened eggs, dead facehuggers, and cocooned colonists serving as incubators for the alien embryos. The marines kill a newborn alien after it bursts through a colonist's chest, rousing several adult aliens who ambush the marines, killing or capturing many. When the inexperienced Gorman panics, Ripley assumes command and rams their armored personnel carrier into the nest to rescue Corporal Dwayne Hicks, and Privates Hudson and Vasquez. Hicks orders the dropship to recover the survivors, but a stowaway alien kills the pilots, causing the dropship to crash into the station. Low on ammunition and resources, the survivors barricade themselves inside the colony facility. Ripley discovers that Burke ordered the colonists to investigate the derelict spaceship containing the alien eggs, intending to profit by recovering them for biological weapon research. Before she can expose Burke, Bishop reports that the dropship crash damaged the power plant's cooling system, and it will soon overheat and explode, destroying the colony. Bishop volunteers to travel to the colony transmitter and remotely pilot the remaining dropship to the surface. Asleep in the medical lab, Ripley and Newt awaken to find themselves trapped with the two released facehuggers. Ripley triggers a fire alarm to alert the marines, who rescue them and kill the creatures. She accuses Burke of releasing the facehuggers to implant her and Newt with alien embryos to smuggle them through Earth's quarantine. The power is suddenly cut, and aliens attack through the ceiling. In the ensuing firefight, the aliens kill Burke, subdue Hudson, and injure Hicks; the cornered Gorman and Vasquez sacrifice themselves to avoid capture. Newt is separated from Ripley and taken by the creatures. Ripley takes Hicks to the dropship but refuses to abandon Newt and arms herself before descending into the processing station hive alone to rescue her. During their escape, they encounter the alien queen amid dozens of eggs. When one opens, Ripley burns the eggs and blows up the queen's ovipositor. Pursued by the enraged queen, Ripley and Newt reach the dropship and escape with Bishop and an unconscious Hicks moments before the station explodes, consuming the colony in a nuclear blast. Aboard the Sulaco, the queen, stowed away in the dropship's landing gear, attacks the group. The queen rips Bishop in half and advances on Newt, but Ripley battles the creature using an exosuit cargo loader, expelling it into space through an airlock while the damaged Bishop shields Newt. Ripley, Newt, Hicks, and Bishop then enter hypersleep for their return trip to Earth.

The commercial space tug Nostromo is returning to Earth with a seven-member crew in "stasis": captain Dallas, executive officer Kane, warrant officer Ripley, navigator Lambert, science officer Ash, and engineers Parker and Brett, along with the ship's cat, Jones. The ship's computer, "Mother", detects a transmission from a nearby planet and wakes the crew. Following company policy to investigate transmissions indicating intelligent life, they leave their payload in orbit and land on the surface, but the ship is damaged. Dallas, Kane, and Lambert discover that the transmission comes from a derelict alien vessel. Inside is a giant, fossilized alien corpse with a hole in its torso. Meanwhile, Mother partially deciphers the transmission, which Ripley determines is a warning beacon and not an SOS as first thought. Kane enters a chamber containing hundreds of large eggs. When he touches one, an arthropod -like lifeform springs out, penetrates his helmet, and attaches to his face. Back at the Nostromo, Ripley refuses to allow them aboard, citing quarantine regulations, but Ash disobeys her. While the engineers work on ship repairs, Ash attempts to extricate the creature from Kane's face; he stops when he discovers that its highly corrosive acidic blood could harm Kane and damage the ship's hull. The creature eventually detaches itself and dies. After the crew returns to space, Kane awakens and seems well. During a final crew meal before returning to stasis, he suddenly chokes and convulses as a small alien creature bursts from his chest and escapes into the ship. After ejecting Kane's body into space, the crew uses tracking devices to try to locate and kill the creature. Encountering Jones, Brett follows him into a landing leg compartment, where the now fully-grown alien kills him. The crew determines that the alien is moving around the ship within the air ducts, and Dallas devises a plan to force the creature off the ship with an airlock. Dallas asks Mother about alternative methods of killing the alien and their chances of succeeding, but the computer ominously refuses to answer his questions. Dallas then enters the ducts with a flamethrower but is ambushed and killed by the alien. A hysterical Lambert believes that they will all die and suggests abandoning the Nostromo and leaving in the ship's escape shuttle. Ripley, now in command, rejects the plan because the shuttle can not support the remaining four crew members. Ripley decides they will try Dallas's plan again. She accesses Mother herself and discovers a secret company directive: Ash must return with the alien for study, regardless of risk to the crew. Ash attempts to kill her when confronted, and Parker attacks and incapacitates Ash, who is now revealed to be an android. Ash states that the alien can not be killed and expresses admiration for it. Parker incinerates Ash's remains. With no hope of defeating the alien, Ripley decides to initiate the Nostromo ' s self-destruct sequence and go ahead with Lambert's plan to abandon the ship. While they are gathering supplies, the alien kills both Parker and Lambert. Now alone, Ripley starts the self-destruct process, but the alien blocks her route to the escape shuttle. Ripley narrowly escapes and turns back to abort the sequence but fails to return before the override option expires. With only a few minutes left to evacuate, Ripley frantically returns to the shuttle and finds that the alien is gone. She takes Jones, boards the shuttle and launches it seconds before the Nostromo explodes. As Ripley prepares for stasis, she discovers that the alien has stowed itself in a narrow compartment aboard the shuttle. She dons a spacesuit and helmet, loads a grappling hook gun, and straps herself to a chair before she begins discharging gases to drive the alien from its hiding place. It tries to attack her, but she opens the shuttle door. The resulting depressurization blast leaves the alien clinging to the door frame. Ripley shoots it with the gun, knocking it out, but the door closes on the grapple line, leaving the alien tethered to the ship. As it swings behind an engine nacelle, Ripley fires the engines to sever the line and blast the alien into space. After recording her log entry, she places Jones and herself into stasis to start their return journey to Earth.

Jack Torrance takes a caretaker position to look after the remote Overlook Hotel in the Colorado Rocky Mountains while it is closed for the winter. On arrival hotel manager Stuart Ullman informs Jack that a previous caretaker, Charles Grady, killed his wife, two young daughters and himself in the hotel a decade prior. At home in Boulder, Jack's son Danny has a premonition and seizure; Jack's wife, Wendy, tells the doctor about a past incident when Jack accidentally dislocated Danny's shoulder during a drunken rage. Jack has been sober ever since. Before leaving for the seasonal break, the Overlook's head chef, Dick Hallorann, informs Danny of a telepathic ability the two share, which Hallorann's grandmother called "shining". He tells Danny that the hotel also "shines" due to its residual and unpleasant history and warns him to avoid Room 237. A month passes, and Danny starts having frightening visions, including those of the murdered Grady sisters. Meanwhile, Jack's mental health deteriorates; he suffers from writer's block, is prone to violent outbursts, and has dreams of killing his family. Danny gets lured to room 237 by unseen forces, and Wendy later finds him with signs of physical trauma, for which she blames Jack. Jack defiantly sulks in the ballroom, where ghostly bartender Lloyd entices him back to drinking. Wendy tells him that Danny was attacked by a "crazy woman" in room 237. Jack investigates and encounters a hideous female ghost in the bathroom, but tells Wendy he saw nothing. He blames Danny for inflicting the bruises on himself and reacts angrily when Wendy suggests leaving the hotel. Danny enters a trance and telepathically contacts Hallorann. Returning to the ballroom, Jack finds it filled with ghostly figures, including waiter Delbert Grady, who urges Jack to "correct" his wife and child. Wendy finds Jack's manuscript written with nothing but countless repetitions of the proverb " All work and no play makes Jack a dull boy ". When Jack threatens her life, Wendy knocks him unconscious with a baseball bat and locks him in the kitchen pantry, but she and Danny are snowed in—Jack previously sabotaged the hotel's two-way radio and snowcat. Back in their private apartment, Danny begins to chant, from a murmur, "red rum" more and more loudly ("red RUM") and writes it out in lipstick on the bathroom door. Wendy sees the word in the mirror; it spells out MURDER in reverse; she panics. Grady frees Jack, who goes after Wendy and Danny with an axe. Taking shelter in the bathroom, Wendy fights Jack off with a knife when he tries to break through the door; Danny escapes out the bathroom window. Hallorann, having flown back to Colorado from his winter home in Florida, reaches the hotel by snowcat. Jack ambushes and murders him with the axe, then pursues Danny into an expansive hedge maze on the hotel grounds. With trepidation Wendy runs through the hotel looking for Danny, encountering the hotel's ghosts, Hallorann's bloody corpse, and a vision of cascading blood from an elevator similar to Danny's premonition. Danny carefully backtracks in the snow to mislead Jack and hides behind a snowdrift. While Jack rushes ahead without a trail to follow and becomes lost, Danny exits the maze and is found by Wendy. The two depart the Overlook in Hallorann's snowcat, leaving Jack to freeze to death in the maze. Meanwhile, a photograph in the hotel hallway pictures a man, by all appearances Jack, standing amidst a crowd of party revelers from July 4, 1921.

In Antarctica, a Norwegian helicopter pursues a sled dog to an American research station and lands. The passenger fumbles a grenade and destroys the helicopter as the pilot continues the chase on foot with a rifle. The pilot shouts in Norwegian and fires at the dog, hitting one of the Americans, before he is shot dead in self-defense by station commander Garry. The American helicopter pilot, R. J. MacReady, and Dr. Copper leave to investigate the Norwegian base. Among the charred ruins and frozen corpses, they find the burnt corpse of a malformed humanoid, which they transfer to the American station. Their biologist, Blair, autopsies the remains and finds a normal set of human organs. Clark kennels the sled dog, and it soon metamorphoses and absorbs several of the station dogs. This disturbance alerts the team, and Childs uses a flamethrower to incinerate the creature. Blair autopsies the Dog-Thing and surmises it is an organism that can perfectly imitate other life forms. Data recovered from the Norwegian base leads the Americans to a large excavation site containing a partially buried alien spacecraft, which Norris estimates has been buried for over a hundred thousand years and a smaller, human-sized dig site. Blair grows paranoid after running a computer simulation that indicates the creature could assimilate all life on Earth in a matter of years. The group implements controls to reduce the risk of assimilation. The remains of the malformed humanoid assimilate an isolated Bennings, but Windows interrupts the process and MacReady burns the Bennings-Thing. The team also imprisons Blair in a tool shed after he sabotages all the vehicles, kills the remaining sled dogs, and destroys the radio to prevent escape. Copper suggests testing for infection by comparing the crew's blood against uncontaminated blood held in storage, but after learning the blood stores have been destroyed, the men lose faith in Garry's leadership, and MacReady takes command. He, Windows, and Nauls find Fuchs' burnt corpse and speculate that he committed suicide to avoid assimilation. Windows returns to base while MacReady and Nauls investigate MacReady's shack. During their return, Nauls abandons MacReady in a snowstorm, believing he has been assimilated after finding his torn clothes in the shack. The team debates whether to allow MacReady inside, but he breaks in and holds the group at bay with dynamite. During the encounter, Norris appears to suffer a heart attack. As Copper attempts to defibrillate Norris, his chest transforms into a large mouth and bites off Copper's arms, killing him. MacReady incinerates the Norris-Thing, but its head detaches and attempts to escape before also being burnt. MacReady thinks that the Norris-Thing demonstrated that every part of the Thing is an individual life-form with its own survival instinct. He proposes testing blood samples from each survivor with a heated piece of wire and has each man restrained, but is forced to kill Clark after he lunges at MacReady with a scalpel. Everyone passes the test except Palmer, whose blood recoils from the heat. Exposed, the Palmer-Thing transforms, breaks free of its bonds, and infects Windows, forcing MacReady to incinerate them both. Childs is left on guard in the main building while MacReady, Garry and Nauls go to test Blair. They find that he has escaped and has been using vehicle components to assemble a small flying saucer, which they destroy. Upon their return, Childs is missing, and the power generator has been destroyed, leaving the men without heat. MacReady surmises that, with no escape left, the Thing intends to return to hibernation until a rescue team arrives. The three men agree that the Thing cannot be allowed to escape and set explosives to destroy the station but the Blair-Thing kills Garry, and Nauls disappears. The Blair-Thing transforms into an enormous creature and breaks the detonator but MacReady triggers the explosives with a stick of dynamite, destroying the station and the Blair-Thing. While MacReady sits by the burning remnants, Childs returns, claiming he got lost in the storm while pursuing Blair. Exhausted and slowly freezing to death, they acknowledge the futility of their distrust and share a bottle of J&B Scotch whisky.

Oskar resides with his mother in the Swedish suburb of Blackeberg in 1982. His classmates bully him, and he spends his evenings imagining revenge. One evening, he meets Eli, who appears to be a girl his age. Eli has moved into the adjoining apartment with a man, Håkan. Eli informs Oskar that they cannot be friends, but the two begin exchanging coded messages through their shared wall. Eli learns that Oskar is being bullied by schoolmates and encourages him to stand up for himself. Oskar then enrolls in exercise classes after school. Håkan kills a person on a footpath to harvest blood for Eli, but is interrupted by a passerby. Eli is prompted to waylay and kill a man, Jocke. A recluse witnesses the attack from his flat but doesn't report the incident. Håkan hides Jocke's body in a hole in the lake. Håkan makes another effort to obtain blood for Eli by trapping a boy in a room after school. When he is unsuccessful, Håkan pours acid onto his own face to avoid identification. Eli visits Håkan in the hospital, where he offers his own neck for feeding. Eli drains him of his blood, and Håkan falls out the window. Eli goes to Oskar's apartment and spends the night with him, during which they agree to "go steady", though Eli states, "I'm not a girl". While on a field trip, the bullies again harass Oskar, who this time hits their leader in the head with a pole, injuring him. On that same trip, some of Oskar's classmates discover Jocke's body. Oskar suggests that he and Eli form a bond and cuts his hand. Eli laps up his blood then runs away. Jocke's friend Lacke has a fight with his girlfriend Virginia, and afterward Eli attacks her. She survives but discovers that she has become sensitive to sunlight. Oskar confronts Eli, who admits to being a vampire. Oskar is upset by Eli's need to kill people for survival. Eli insists that they are alike, in that Oskar wants to kill and Eli needs to kill, and encourages him to "be me, for a little while." While in the hospital, Virginia asks an orderly to open the blinds in her room, and bursts into flames, committing suicide. Lacke sets out to kill Eli, whom he finds asleep in the apartment's bathtub. Oskar intervenes, and Eli wakes up and feeds on Lacke's blood. Afterward, Eli thanks Oskar and kisses him. Fearing that they've attracted too much attention from the neighbors, Eli decides that it isn't safe to stay and leaves that night. Oskar is lured out to resume the program at the pool. One of the bullies holds Oskar under the water. Eli arrives and rescues him by killing and dismembering the bullies, except for one, who is left sobbing on a bench. Oskar is seen travelling on a train, with Eli in a box beside him. Eli taps the code for "kiss" to Oskar, who responds the same.

The United States is devastated by a mysterious phenomenon that reanimates recently-dead human beings as flesh-eating zombies. At the dawn of the crisis, it has been reported that millions of people have died and reanimated. Despite the government's best efforts, social order is collapsing. While rural communities have natural barriers, such as Johnstown, and the National Guard have been effective in fighting the zombie hordes in open country, urban centers have descended into chaos. At WGON-TV, a television studio in Philadelphia, traffic reporter Stephen Andrews and his pregnant girlfriend, producer Francine Parker, are planning to steal the station's helicopter to escape the city. Across town, Philadelphia Police Department SWAT officer Roger DeMarco and his team raid a low-income housing project, whose mostly black and Latino tenants are defying the martial law of delivering their dead to the National Guard. The tenants and the officers exchange gunfire as the officers try to gain entry, and indiscriminate attacks by racist officers and the reanimated dead exacerbate the resulting chaos. Roger encounters an officer from another unit, Peter Washington. As the SWAT team successfully dispatch the zombies, a disillusioned Roger suggests that he and Peter desert and join up with Stephen (who is Roger's friend) in escaping the city. Roger and Peter join Fran and Stephen at a police dock and then leave Philadelphia in a stolen WGON-TV news helicopter. Following some close calls while stopping for fuel, the group comes across a shopping mall, and decide to remain there since there is plenty of food, medicine, and all kinds of consumables. Roger, Peter and Stephen camouflage the entrance to the stairwell leading to their safe room and block the mall entrances with trucks to keep the undead from penetrating. This involves driving through crowds of zombies, who attack the trucks. Roger becomes reckless and is soon bitten by the zombies. After clearing the mall of zombies, the group builds a hidden safe room as a fallback in case of future attacks, before settling into a hedonistic lifestyle with all the goods available to them. Roger eventually succumbs to his wounds and dies; when he reanimates, Peter shoots him in the head and buries his body in the mall. Months later, all emergency broadcast transmissions cease, suggesting that the government has collapsed. Now isolated, the three load some supplies into the helicopter, in case they might need to leave suddenly. Fran gets Stephen to teach her how to fly in case he is killed or incapacitated. A nomadic biker gang sees the helicopter in flight and breaks into the mall, destroying the barriers and allowing hundreds of zombies back inside. Despite having a fallback plan should the mall be attacked, Stephen, consumed by territorial rage, takes matters into his own hands by firing on the looters, beginning a protracted battle. On their way out, straggling bikers are overwhelmed and eaten by the zombies. Stephen tries to hide in the elevator shaft, but gets shot and subsequently mauled by roaming zombies. When Stephen reanimates, he instinctively returns to the safe room and leads the undead to Fran and Peter. Peter kills the undead Stephen while Fran escapes to the roof. Peter, not wanting to leave, locks himself in a room and contemplates suicide. When the zombies burst in, he has a change of heart and fights his way up to the roof, where he joins Fran. Having escaped and low on fuel, the two then fly away in the helicopter to an uncertain future.

At a San Francisco pet store, socialite Melanie Daniels meets lawyer Mitch Brenner, who wants to buy lovebirds for his sister Cathy's 11th birthday. Mitch recognizes Melanie from her court appearance regarding a practical joke gone awry and pretends to mistake her for a shop employee. He tests Melanie's knowledge of birds, which she fails, then discloses his knowledge of her and leaves. Intrigued, Melanie buys the lovebirds and drives to Bodega Bay after learning that Mitch has gone to his family's farm there. She learns Cathy's name from Annie Hayworth, a teacher at Bodega. Annie is Mitch's ex-lover, but their relationship ended due to his overbearing mother, Lydia, who feels insecure about any woman in Mitch's life. Melanie rents a boat and crosses the bay to discreetly leave the lovebirds at the Brenner farm. Spotting her departing, Mitch drives to meet her at the dock. At the wharf, Melanie is attacked by a gull. Mitch tends to her wound and invites her to dinner. At the farm, Lydia's hens are refusing to eat. Lydia dislikes Melanie due to her exaggerated reputation, as reported in gossip columns. The passing of Mitch's father four years ago is also brought up. Mitch invites Melanie, who is staying with Annie, to Cathy's birthday party being held the next day. Later, a dead gull is found at Annie's door. During Cathy's party, Melanie tells Mitch about her troubled past and her mother running off with another man when she was Cathy's age. During a game, the children are attacked and wounded by gulls. Later that evening, as Melanie dines with the Brenners, sparrows swarm the house through the chimney. Mitch insists that she delay driving back to San Francisco and stay the night. The next morning, Lydia visits her neighbor to discuss the problem with their chickens. She discovers broken windows in his bedroom and his eyeless corpse, pecked by birds, and flees in horror. While recovering at home, Lydia fears for Cathy's safety, and Melanie offers to pick her up at school. As Melanie waits outside the schoolhouse, a flock of crows engulf the jungle gym behind her. Anticipating an attack, she warns Annie. Rather than leaving the students in the building with its large windows, they evacuate them, and the crows attack later. Mitch finds Melanie at the diner. A heated debate ensues among those present whether the bird attacks are real, including an ornithologist who refuses to take these events seriously. When gulls attack a gas station attendant, Mitch and other men assist him outside. The spilled gasoline is ignited by an unaware bystander's match, causing an explosion. During the escalating fire, Melanie and others rush out, but more gulls attack. Melanie takes refuge in a telephone booth. Mitch saves her, and they return to the diner, where Melanie is blamed by a patron taking cover inside for the events unfolding in Bodega Bay. Mitch and Melanie go to Annie's house to fetch Cathy and find Annie's body outside; she was killed by the crows while protecting Cathy. They take a traumatized Cathy home. That night, Melanie and the Brenners barricade themselves in the family home, which is attacked by birds. After discovering that the birds have pecked their way in through the roof, Melanie is trapped and severely wounded, but Mitch pulls her out. Mitch insists they all drive to San Francisco to take Melanie, now injured, traumatized and catatonic, to a hospital. As Mitch readies Melanie's car for their escape, a sea of birds has gathered around the Brenner house. The car radio reports bird attacks on nearby communities and that the military may intervene. Cathy retrieves her lovebirds (the only birds who do not attack) from the house and joins Mitch and Lydia as they escort Melanie past a mass of birds and into the car. The car slowly drives away as the birds watch.

In the first section of the film, the cast and crew of a low-budget zombie film called True Fear are shooting at an abandoned water filtration plant. Director Higurashi, desperate for film success due to mounting debts and frustrated at the actors' work, arranges for a blood pentagram to be painted to revive real zombies per the plant's haunted past. The cameraman turns into a zombie and bites assistant director Kasahara, turning him into one as well. Actress Chinatsu, actor Ko, and makeup artist Nao lock the zombies out of the plant. Higurashi insists they continue filming using the real zombies. The sound engineer rushes out of the plant and is infected. Higurashi brings the zombified sound engineer back in for more footage, throwing him at the actors. Nao decapitates the zombified sound engineer and is splattered with zombie blood. Chinatsu, Ko, and Nao attempt to escape, but Higurashi facilitates an attack by zombified Kasahara while he films. Chinatsu is confronted by the zombies and saved by Ko. They reunite with Nao, who suspects that Chinatsu is infected. Nao attempts to kill Chinatsu and chases her, dispatching the zombies in the process. Chinatsu escapes to a roof, with Nao and Ko following. Offscreen, Ko kills Nao with an axe to save Chinatsu. Chinatsu thinks she is infected and runs away to a building with a pentagram painted on the outside wall. An unidentified zombie approaches Chinatsu and leaves. Chinatsu also exits the building, finding an axe before seeing Ko wandering on the roof. She approaches Ko to find that he has been zombified. Chinatsu confronts zombified Ko in a scene similar to the start of the film, and after being briefly interrupted by a mysteriously revived Nao, Chinatsu decapitates zombified Ko. Higurashi berates Chinatsu for going off script. Chinatsu kills Higurashi, and she ends the first section by standing on the blood pentagram in a trance-like state. The second section of the film is a flashback involving the personal lives of the fictional cast and crew of a production called One Cut of the Dead, a film-within-the-film of the same title (thus making True Fear a film-within-the-film within another film-within-the-film). Takayuki Higurashi, director of a TV drama starring alcoholic actor Manabu Hosoda, is approached by network executives to direct a low-budget zombie film in one take to launch the new Zombie Channel. He is initially reluctant, but accepts in hopes of reconnecting with his daughter Mao, a horror movie fanatic. Actors cast for One Cut of the Dead include idol Aika Matsumoto as Chinatsu, cynical actor Kazuaki Kamiya as Ko, Shunsuke Yamagoe as the sound engineer, and Hosoda as the cameraman. The One Cut of the Dead movie-within-the-movie is also revealed to be a live show, so no reshoots or delays are possible. The third section of the film depicts the chaotic shooting of One Cut of the Dead from behind the scenes. The actors cast as director and makeup artist could not make filming, forcing Takayuki and his wife Harumi to step in to fill their respective roles. During the shooting, Takayuki overacts his first scene by physically accosting Matsumoto. Hosoda passes out drunk and later vomits. Yamagoe's diarrhea leads to his character leaving the plant off-script. Dealing with these forces Takayuki and the other actors to start to improvise and make small talk. The main cameraman suffers a back injury and has to be replaced. Harumi goes off-script and attacks various real cast and crew during the scene of Nao chasing Chinatsu, forcing Takayuki to choke her out and later forcibly remove her from interrupting the ending scene between Chinatsu and Ko after she abruptly wakes up. The zombie who did not attack Chinatsu turns out to be a crew member giving instructions. The camera crane accidentally gets broken, forcing the real cast and crew to form a human pyramid in order to mimic a crane shot for the final shot, with Mao having to hold the camera standing atop Takayuki's shoulders. The faux-crane shot is successful, and the real cast and crew are elated at the successful filming. The final credits are shown over footage of the real-life filming by the One Cut of the Dead crew, including the faux-crane shot being taken from the top of a stepladder.

Outside Paris, a woman dumps a corpse in the river. The body is identified by Dr. Génessier as his daughter Christiane, who was reported missing after an automobile crash disfigured her face. In reality, Christiane still lives in Dr. Génessier's mansion next to his private clinic, guarded by German Shepherds and other large dogs. The body (which was disposed of by his assistant Louise) belongs to a young woman whose facial skin Dr. Génessier removed and unsuccessfully attempted to graft onto his daughter. After her father leaves with promises to restore her face, Christiane, wearing a mask to cover her disfigurement, calls her fiancé, Jacques Vernon, Dr. Génessier's assistant, but hangs up without saying a word. Génessier's next victim is Edna Grüber, a young woman whom Louise befriends and lures to Génessier's mansion with an offer of a room for rent. Génessier sedates Edna with chloroform, and he and Louise carry her to the lab to prepare her for surgery, secretly watched by Christiane. Later, he removes Edna's facial skin and grafts it onto Christiane's face. The heavily bandaged and faceless Edna attempts to escape but falls to her death from an upstairs window. After disposing of Edna's corpse, Génessier notices the new tissue is rejected within days, and Christiane has to wear the mask again. She phones Jacques and says his name, but Louise interrupts the call. Jacques informs the police, who have been investigating the disappearance of young women with similar facial characteristics. Jacques realizes one of the girls looks like Louise. Inspector Parot instructs Paulette Mérodon (recently arrested for shoplifting) to check herself into Génessier's clinic. Soon after, Paulette is picked up by Louise and delivered to Dr. Génessier. Before he begins surgery on Paulette, the police arrive. While the doctor talks with the police, Christiane, disenchanted with her father's immoral experiments, while slowly losing her mind from guilt and isolation, decides to act. She frees Paulette and murders Louise by stabbing her in the neck. She also frees the dogs and doves that her father uses for experiments. Dr. Génessier dismisses the police (who readily accept his explanations) and returns to his lab. There, a newly acquired German Shepherd attacks him, inciting the other dogs to follow suit, mauling him to death. Christiane, unmoved by his death, strolls out into the woods outside with a dove in her hands.

In 1945, Grace Stewart resides in a remote country house in Jersey, a Channel Island formerly occupied by the Germans. As her young children, Anne and Nicholas, suffer from a severe sensitivity to light, Grace keeps the home darkened with heavy curtains. One day, Mrs. Bertha Mills, Edmund Tuttle and the mute Lydia arrive seeking employment. Grace hires them as the housekeeper, gardener, and maid, and learns they worked in the house years earlier. Anne claims to be visited by a young boy named Victor, his parents, and an elderly blind woman. Grace believes this is a fantasy, but after she hears footsteps and voices, she orders the house to be searched for intruders. In a storage room, she finds a nineteenth-century album containing photographs of corpses. Mrs. Mills recounts that many left the house in 1891 due to an outbreak of tuberculosis. Grace begins to fear there are supernatural entities in the house, but struggles to reconcile this with her Catholic faith. Grace witnesses a piano playing itself and becomes convinced that the house is haunted. She runs outside in search of the local priest to bless the house and instructs Tuttle to check the gardens to see if a family has been buried there. Mrs. Mills instructs Tuttle to conceal gravestones with leaves. In the woods, Grace runs into her husband, Charles, whom she thought was killed in World War II, and brings him back to the house. One day, Grace checks on Anne playing. To her horror, she finds an old woman wearing Anne's veiled communion dress who speaks in Anne's voice. Grace attacks the woman but finds she has actually attacked Anne. Charles tells Grace he must return to the front, rejecting her insistence that the war is over. He leaves the next morning. Grace is horrified to find all of the curtains in the house have been removed, exposing Anne and Nicholas to sunlight. She accuses the servants and expels them. That night, the children discover that the headstones in the cemetery belong to the servants, and flee when the servants approach them. Grace finds a postmortem photograph of Mrs. Mills, Tuttle and Lydia, who all perished during the 1891 tuberculosis outbreak. Mrs. Mills tells Grace to talk to the "intruders". Grace discovers that the elderly blind woman is a medium holding a séance with Victor's parents. They have discovered via automatic writing that Grace, despondent after Charles died in the war, smothered her children with a pillow and shot herself. Aghast, Grace realizes that the intruders are the living family, and that she, her children and the servants are haunting the house. Embracing her children, Grace admits to her act of murder–suicide: she awoke after her suicide and believed that God had brought everyone back to life for a second chance. Victor and his family move out. Anne and Nicholas realize that sunlight no longer hurts them and enjoy it for the first time. The house goes up for sale and Mrs. Mills informs the Stewarts that they will have to learn to cohabit with future inhabitants. Grace and the children affirm that the house is theirs and that they will not leave.

A deer is hit by a truck and reanimates after the truck leaves. Seok-woo, a cynical workaholic and divorced father in Seoul, messes up a birthday present for his estranged daughter Su-an, and misses out on her recital of the Hawaiian folk song " Aloha ʻOe ". He agrees with Su-an to take her to see her mother, Na-young, in Busan. The next day, they board the KTX 101 for Busan at Seoul Station, along with blue-collar worker Sang-hwa and his pregnant wife Seong-kyeong, high-ranking executive Yon-suk, a high school baseball team including player Yong-guk and his cheerleader girlfriend Jin-hee, elderly sisters In-gil and Jong-gil, and a traumatized homeless man. Just before departure, a scraped up woman boards the train unnoticed at the last minute. News reports reveal that an outbreak is occurring across the country, and the scraped up lady then turns into a zombie. She bites and infects a train attendant, sparking a rapid outbreak on the train. The survivors flee to other carriages and secure the doors, trapping the horde in the process. The train passes through Cheonan station, and continues onto Daejeon Station, where a group of soldiers were deployed to keep the infection at bay. Seok-woo is notified that his company sent an extraction team to pick him and Su-an up. After stopping at Daejeon, the passengers disembark from the train, but find that the deployed soldiers and those from Seok-woo's company had also fallen to the horde. The passengers flee back to the train, becoming separated into different carriages in the commotion. The conductor cancels all future stops except for Busan, where the army has established a quarantine zone. Seok-woo, Sang-hwa, and Yong-guk arm up, sneak and fight through the zombie horde to reunite with Su-an, Seong-kyeong, In-gil, and the homeless man in another carriage. The remaining passengers, fearing that the survivors are infected, refuse to let them into their carriage and block the door. Seok-woo and the others start to try to get into the safe carriage, however, Sang-hwa is bitten during the process. He tells Seok-woo to look after Seong-kyeong, name their daughter Yoon Su-yun, and sacrifices himself to buy the others time to force open the door, but In-gil is left behind in the process. Yon-suk, train attendant Ki-chul, and the other passengers demand that the new passengers leave their train compartment and isolate themselves in the front vestibule. Jong-gil, disgusted at everyone else's selfishness and paranoia, opens the door to let the zombies in and kill everyone else left onboard. Yon-suk and Ki-chul manages to escape by hiding in a bathroom. Seok-woo learns from a phone call that his company was indirectly responsible for the outbreak. A blocked track at Dongdaegu Station forces the train to stop, and the driver disembarks to search for another train. Yon-suk escapes after pushing Ki-chul into the zombies. A flaming locomotive barrels in and crashes into some of the zombie-filled passenger carriages, trapping Seok-woo, Su-an, Seong-kyeong, and the homeless man beneath a toppled carriage. Yong-guk and Jin-hee got split up from the party and are used as bait by Yon-suk, as he escapes on the new train. The conductor starts up another train on a separate track and tries to help an injured Yon-suk, but is mauled in the process. The homeless man sacrifices himself so Seok-woo, Su-an, and Seong-kyeong find their way out from under the carriage. Seok-woo, Su-an, and Seong-kyeong board the new train, only to find an infected Yon-suk, who desperately begs them for help before turning into a zombie. Seok-woo fights him and manages to throw Yon-suk off the train, but his hand is bitten during the tussle. In his last moments of consciousness, he puts Su-an and Seong-kyeong inside the engine room, tells Seong-kyeong how to drive the train, and says goodbye to Su-an. Seok-woo, before succumbing to the infection, runs to the back of the train and reminisces about Su-an's birth before throwing himself off the train. The surviving pair arrive at a blockade of corpses and barbed wire outside a tunnel near Busan, and both walk through the tunnel, with Su-an singing "Aloha 'Oe" to calm her nerves and pay tribute to her father. Su-an and Seong-kyeong are met by the army, who bring both of them to safety.