Sarah is picked up by her husband Paul and daughter Jessica after a whitewater rafting trip with her thrill-seeking friends Juno and Beth. Paul is distracted on the ride home, causing a car crash that kills both him and Jessica. Sarah awakens in the hospital and collapses after Beth tells her about their deaths. One year later, Sarah, Juno, and Beth reunite for a spelunking adventure in the Appalachian Mountains of North Carolina along with sisters Sam and Rebecca, and newcomer Holly. They hike to a mountain cave entrance and descend. Making their way through the caves, Sarah becomes stuck in a narrow tunnel, but manages to escape before it collapses, blocking the way back. Juno admits that she has led the group into an unexplored cave system instead of the mapped one they had filed with local authorities, which means that a rescue party would be unable to locate them. The group searches for an exit and discovers old climbing equipment and a cave painting that suggests a way out. Holly, thinking she sees sunlight, runs ahead but falls into a hole and breaks her leg. As the others help her, Sarah wanders off and sees a pale, humanoid creature drinking from a pool before it scampers away. Later, they come across a den of animal bones and are suddenly attacked by a creature they call a "crawler", which kills Holly. Sarah runs, but falls down a hole and is knocked unconscious. Juno, trying to stop Holly's body from being dragged away, kills a crawler with her pickaxe, but then accidentally stabs Beth in the neck after being startled. Beth grabs Juno's pendant as she collapses and a traumatized Juno flees. Sarah awakens in a den of human and animal carcasses to see Holly's body being mauled and eaten by crawlers. Juno discovers cave markings left by previous explorers pointing to a potential exit from the caves. She finds and saves Sam and Rebecca from a crawler, and Sam deduces that the creatures are blind and hunt by sound. Sarah finds a dying Beth, who reveals both that Juno stabbed her and that Juno's pendant was a gift from Paul, confirming Sarah's suspicions that Juno and Paul were having an affair. Beth begs Sarah to end her suffering, and Sarah reluctantly kills her with a rock. Sarah then encounters several crawlers and manages to kill them all, falling into a blood-filled pool in the process. Elsewhere, Juno, Sam, and Rebecca are pursued by a large group of crawlers. They reach a chasm, and Sam tries to climb across but is attacked by a crawler on the ceiling. It rips out her throat, but she stabs it before bleeding to death. Rebecca is dragged away and disemboweled as Juno flees. Juno later reunites with Sarah and lies about seeing Beth die. After defeating a group of crawlers near an exit, Sarah confronts Juno, revealing the pendant, and her knowledge of Beth's fate and the affair with Paul. She then stabs Juno in the leg with a pickaxe and leaves her to die as a horde of crawlers approaches. Juno removes the pickaxe from her leg to hold back the crawlers and is heard screaming as Sarah escapes. Sarah falls into a hole and loses consciousness. When she wakes, she sees sunlight and clambers up a bone-strewn slope to escape the cave. She reaches her car and speeds away, eventually pulling over to break down in tears. After a truck passes, she vomits out of the window. When she sits back up, she hallucinates seeing a bloodied Juno beside her, and screams. In the UK version, Sarah awakens, still in the cave, and has a vision of Jessica, smiling as the sounds of approaching crawlers grow louder.

Nada is a homeless man who comes to Los Angeles, California in pursuit of work, where he spots a preacher warning that "they" have recruited the rich and powerful to control humanity. He finds employment at a construction site and befriends his coworker Frank, who invites him to live in a shanty town near a church, where he meets their community leader, Gilbert. A hacker takes over TV broadcasts, alerting that humanity is "their cattle" and the only way to unfold the truth is to shut off the signal at its source. Those watching the broadcast complain of headaches. Nada follows Gilbert and the preacher into the church, discovering a recording of gospel music playing that unbeknownst to Nada obscures a meeting with a group including the hacker. Nada also uncovers equipment and boxes inside, but escapes when he bumps into the preacher. The shantytown and church are destroyed in a police raid, and the hacker and preacher are brutalized by law enforcement officers. Nada retrieves one of the boxes from the church and takes a pair of sunglasses from it, concealing the box in a trash pile. He finds out that they make the world appear monochrome and reveal subliminal messages in the media to consume and conform. They also disclose that many people are ghoulish, bug-eyed aliens hiding under human façades. Additionally, the creatures have wristwatch communicators that allow them to teleport, along with surveillance drones. When aliens at a supermarket realize that Nada can detect them, he is confronted by two alien police officers. He kills them, steals their guns, and enters a bank, where he sees that multiple employees and customers are aliens. He kills several and escapes by taking a human, Holly Thompson, hostage. Nada attempts to persuade her to put on the glasses, but she throws him out of a window. While speaking to the police, Holly realizes that Nada dropped his glasses on her carpet. While Nada retrieves another pair of sunglasses from the trash pile, Frank comes to give him his paycheck and orders him to stay away following Nada's killing spree becoming widespread news. Realizing that Frank is not one of the aliens, Nada pleads with Frank to put on the glasses, but he refuses, and eventually the two come to blows. After a long and painful fight, Nada subdues Frank, and places the glasses on his face. Seeing the aliens for himself, and now believing Nada, Frank agrees to go into hiding together. The two run into Gilbert, who introduces them to the human resistance. They are given contact lenses to replace the sunglasses and learn about the aliens using global warming to xenoform Earth's atmosphere to be more like their homeworld's while depleting its resources for their own gain. They also learn that the aliens have been bribing human collaborators in exchange for wealth. Holly joins the meeting, bringing information about where the signal may be originating. Soon afterwards, the meeting is raided by police, with the majority of those present killed and the survivors scattered. Nada and Frank are cornered in an alley, but Frank activates an alien wristwatch, opening a portal to the alien's spaceport on Earth under Cable 54, an alien-run news network. Coming across a meeting of aliens and wealthy collaborators celebrating the defeat of the human resistance, they are approached by a drifter from the shanty town, now a collaborator. Mistaking them for new recruits, he gives the pair a tour of the facility, where the aliens broadcast a signal that prevents humans from identifying them and their hidden messages. Nada and Frank locate Holly and fight their way to the transmitter on the roof, but Holly, a collaborator responsible for the raid, murders Frank. Nada kills Holly and blasts the transmitter, but is fatally shot by a police helicopter. With the signal shutting down, he gives them the middle finger as he dies from his injuries. Owing to the transmitter being destroyed, humans all over the world discover the aliens hiding among them.

In Montreal, scientist André Delambre is found dead with his head and arm crushed in a hydraulic press. His wife Hélène confesses to the crime but refuses to provide a motive, and begins acting strangely. In particular, she is obsessed with flies, including a supposedly white-headed fly. André's brother, François, lies and says he caught the white-headed fly. Thinking he knows the truth, Hélène asks François to bring the police inspector in charge of the case, Charas, so that she can explain the circumstances of André's death to them both. In flashback, André, Hélène, and their son Philippe are a happy family. André has been working on a matter-transporter device called the disintegrator-integrator. He initially tests it only on small, inanimate objects, such as a newspaper, before proceeding to living creatures, including the family's pet cat (which fails to reintegrate, but can be heard meowing somewhere) and a guinea pig. After he is satisfied that these tests are succeeding, he builds a man-sized pair of chambers. One day, Hélène, worried because André has not come up from the basement lab for a couple of days, goes down to find André with a black cloth draped over his head and a strange deformity on his left hand. Communicating only with typed notes and knocking (once for "Yes", twice for "No"), André tells Hélène that he tried to transport himself, but that a fly was caught in the chamber with him, which resulted in the mixing of their atoms. Now, he has the head and left arm of a fly, though he retains his human mind. Conversely, the fly has a miniature version of his head and left arm. André needs Hélène to capture the fly so that he can reverse the process. After she, her son, and their housemaid exhaustively search for it, she finds it, but it slips out of a crack in the window. André's will begins to fade as the fly's instincts take over his brain. Time is running out, and while André can still think like a human, he smashes the equipment, burns his notes, and leads Hélène to the factory. When they arrive, he sets the hydraulic press, puts his head and arm under, and motions for Hélène to push the button. André's arm falls free as the press descends, and trying not to look, she raises the press, replaces the arm, and activates the machine a second time. Upon hearing this confession, Inspector Charas deems Hélène insane and guilty of murder. As they are about to haul her away, Philippe tells François he has seen the fly trapped in a web in the back garden. François convinces the inspector to come and see for himself. The two men see the fly, with both André's head and arm, trapped on the web as Philippe told them. It screams, "Help me! Help me!" as a large spider advances on it. Just as the spider is about to devour the creature, Charas crushes them both with a rock. Knowing that nobody would believe the truth, François and Charas decide to declare André's death a suicide so that Hélène is not convicted of murder. In the end, Hélène, François, and Philippe resume their daily lives. Sometime later, Philippe and Hélène are playing croquet in the yard. François arrives to take his nephew to the zoo. In reply to his nephew's query about his father's death, François tells Philippe, "He was searching for the truth. He almost found a great truth, but for one instant, he was careless. The search for the truth is the most important work in the whole world and the most dangerous." The film closes with Hélène escorting her son and François out of the yard.

As the students of a Kiev seminary are sent home for vacation, three of them become lost in the countryside in the middle of the night. They spot a farmhouse and ask the old woman at the gate to let them spend the night. She agrees, on the condition that they sleep in separate areas of the farm. As one of the students, Khoma Brutus, lies down in the barn to sleep, the old woman tries to seduce him, which he staunchly refuses. She hypnotizes him, climbs on his back and rides him across the countryside like a horse. Khoma suddenly finds that they are flying and realizes she is a witch. Invoking the name of Christ, he forces her to land and beats her violently with a stick until she turns into a beautiful young woman, who cries out that he is killing her. Terrified, Khoma runs back to his seminary, where the rector informs him that a wealthy sotnik 's dying daughter has specifically requested that Khoma say prayers for her soul. He reluctantly complies and finds he is returning to the farm where he met the witch. The girl dies before he arrives, and to his horror, he realizes she is the witch and that he has caused her death. The sotnik promises Khoma great reward if he will stand vigil and pray for her soul for the next three nights. If he does not, grave punishment is implied. After the funeral rites, the villagers tell the story of a huntsman who was bewitched by the girl and asked her to ride him like a horse, reminding Khoma of his own encounter. Khoma is taken to the chapel where the girl's corpse lies and is locked in for the night. He lights every candle in the chapel and begins to recite the prayers. He pauses to sniff tobacco, and when he sneezes, the girl opens her eyes and climbs out of the coffin. Khoma quickly draws a sacred circle of chalk around himself, which acts as a barrier. Hearing him but unable to see him, the girl persistently tries to get to him as he prays fervently. When the rooster crows in the morning, the girl returns to her coffin and all the candles blow out. Khoma gets drunk to strengthen himself for the second night. He draws the sacred circle again and begins his prayers. The coffin rises into the air and bangs against the sacred circle's barrier, prompting a panicked Khoma to pray for God 's protection. Standing up in the coffin, the girl flies around the sacred circle while repeatedly calling out Khoma's name. As the rooster crows, the coffin returns to its place, and shortly after the girl lies down, she attempts to curse Khoma, causing his hair to turn grey. Trying to explain what happened in the chapel, Khoma pleads with the sotnik to be allowed to leave, but the sotnik threatens him with a thousand lashes if he refuses, while offering him a thousand chervontsy if he completes the task. Khoma attempts to escape but is stopped by the sotnik's servants, who bring him back to the farm. On the third and final night, a drunken Khoma once again draws the sacred circle before beginning his prayers. The girl summons various demonic figures to torment him, but they cannot get past the sacred circle either. She ultimately summons Viy, a large humanoid creature. Khoma believes himself to be safe upon hearing the rooster crow, but when he makes eye contact with Viy, Viy points at Khoma and the demons attack him. The rooster crows again and the demons all flee, leaving Khoma motionless on the floor. The girl turns back into the old woman and lies down in the coffin, which instantly falls apart. The rector enters the chapel and, seeing what has happened, races off to tell the others. Back at the seminary, one of Khoma's two friends proposes they drink to his memory, while the other doubts that Khoma is actually dead.

Shigeharu Aoyama visits his wife Ryoko in hospital, where she dies from an undisclosed illness. Seven years later, Shigeharu's teenage son Shigehiko encourages him to find a new wife. Shigeharu's friend, film producer Yasuhisa Yoshikawa, organizes a fake casting audition at which young women audition for the starring role in a new television series, which was just a ruse for Shigeharu to meet aspiring actresses. Posing as a casting director, Shigeharu is immediately enchanted by an applicant named Asami Yamazaki, who says her career as a ballerina was ended by injuries. Yasuhisa is suspicious when he cannot reach any of the references in Asami's résumé, including a music producer who has gone missing 18 months earlier. Regardless, Shigeharu pursues her anyway. Asami lives in a tiny apartment, containing little more than a large sack and a telephone; she sits perfectly still next to the phone for four days after the audition, waiting for it to ring. When it finally does, she answers and pretends that she never expected Shigeharu to call. After several dates, she accompanies him to a hotel, where Shigeharu intends to propose marriage. She reveals burn scars on her body and, before having sex, demands that Shigeharu pledge his love to her. Deeply moved, he agrees. In the morning, Shigeharu receives a call from the front desk to inform him that Asami has left. Shigeharu tries to track down Asami, but all of the contacts on her résumé are dead ends, as Yasuhisa warned. At the dance studio where she said she trained, he finds a man with prosthetic feet who tortured her by burning her legs when she was a child. The bar where Asami said she worked has been abandoned for a year following the murder and dismemberment of the owner, and a local man tells Shigeharu that the police found an extra tongue, an extra ear, and three extra fingers when they recovered the body. Shigeharu has hallucinations of the body parts. Asami sneaks into Shigeharu's house while he is at work and becomes jealous when she sees a framed picture of Ryoko. She drugs his liquor and kills Gangu, the family dog. Shigeharu comes home, drinks the spiked liquor, and collapses. He has a series of hallucinations, including flashbacks to earlier dates with Asami and sexual experiences with other women from his past. In Asami's apartment, he sees that the sack contains a man who is missing both feet, his tongue, an ear, and three fingers on one hand. He crawls out and begs for food, prompting Asami to vomit into a dog bowl, which he hungrily consumes as Shigeharu watches in horror. He then sees her behead the man with prosthetic feet. When Shigeharu wakes up, Asami informs him he's been injected with a paralytic agent that disables his muscles but leaves him conscious and able to feel, and begins to torture him with acupuncture needles. She tells him that, just like everyone else, he has failed to love only her. She cannot tolerate his feelings for anyone else, even his own son. She inserts needles into his abdomen and below his eyes. She then cuts off his left foot with a wire saw. As she is halfway through cutting off his right foot, Shigehiko returns home from school and Asami attacks him. Shigeharu appears to suddenly wake up back in the hotel, his current ordeal apparently just a nightmare, though this is actually a false awakening. He proposes marriage to Asami, who accepts. As he falls back asleep, he returns to reality to find Shigehiko fighting Asami. Shigehiko overpowers Asami and kicks her down the stairs, breaking her neck. Shigeharu tells Shigehiko to call the police and stares across the room at the dying Asami, who repeats what she said on one of their dates about her excitement over seeing him again.

A man named Alderson awakens in a room that has hatches on each wall and floor, each leading to other rooms. He enters another room and is killed by a hidden wiretrap. Five different people all meet in another room: three men (Quentin, Rennes, and Worth), and two women (Leaven and Holloway). Quentin warns the group that he has seen traps in some of the other rooms. Leaven notices each hatch has plates with three sets of numbers etched into them. Rennes tests his theory that each trap could be triggered by detectors by throwing his boot into a room, and starts moving through the safe rooms. This works for motion detectors and pressure sensors, but fails to trigger the trap in one of the rooms and he is killed by an acid trap. Quentin believes each person was chosen to be there. Leaven hypothesizes that rooms whose plates contain prime numbers are traps. They encounter a mentally disabled man named Kazan, whom Holloway insists be brought along. Tension rises among the group, as well as the mystery of the maze's purpose. Worth admits to Quentin he was hired to design the maze’s shell and guesses that The Cube was created accidentally by a bureaucracy, and that its original purpose has been forgotten and that they have been placed inside only to justify its existence. Worth's knowledge of the exterior dimensions allows Leaven to calculate that the Cube has 17,576 rooms, plus a "bridge" room that would connect to the shell, and thus, the exit. She realizes that the numbers may indicate each room's coordinates. The group travels to the edge but realize every room there is a trap. They successfully traverse a room with a trap. Holloway defends Kazan from Quentin's threats. The group reaches the edge, but can see no exit. Holloway tries to swing over to the shell using a rope made of clothing. The Cube shakes, causing the rope to slip; Quentin catches it at the last second and pulls her up, but then deliberately drops her to her death, telling the others that she slipped. Quentin picks up Leaven and carries her to a different room in her sleep, intending to abandon Kazan and Worth. He tries to assault her, but Worth follows and attacks him. Quentin counters savagely, then throws Worth down a hatch to a different room. Upon landing, Worth starts laughing hysterically; Rennes's corpse is in the room, proving they have moved in a circle. Quentin is horrified, but Worth realizes the room Rennes died in has now moved to the edge of the maze, meaning they haven't gone in a circle at all. Instead, the rooms are moving, and will eventually line up with the exit. Leaven deduces that traps are not tagged by prime numbers, but by powers of prime numbers. Kazan is revealed as a savant who can calculate factorizations in his head instantaneously. Leaven and Kazan guide the group through the cube to the bridge. Worth then traps Quentin in a hatch. He catches up and attempts to attack them, but Worth opens a hatch under him from the room below. All but Quentin travel to the bridge where they open the hatch, revealing a bright light. Quentin reappears and, using a detached door lever, severely injures Leaven and Worth. As Quentin pursues Kazan through the exit, Worth grabs Quentin's legs, trapping him in the bridge’s doorway. The bridge moves, killing Quentin. As the bridge returns to the recesses of the cube, Worth crawls to a fallen Leaven as he too bleeds out. Kazan wanders out into the light.

Catholic priest Sang-hyun volunteers at a hospital, providing ministry to the patients. He eventually volunteers to participate in an experiment to find a vaccine for the deadly Emmanuel Virus (EV). The experiment fails, and Sang-hyun is infected with EV, but makes a complete and rapid recovery after receiving a blood transfusion. News of his recovery spreads among the parishioners of Sang-hyun's congregation, and they begin to believe that he has a gift for healing. Soon, thousands flock to Sang-hyun's services. Among the new churchgoers are Kang-woo, Sang-hyun's childhood friend, and his family. Kang-woo eventually invites Sang-hyun to join the weekly mahjong night at his house. There, Sang-hyun finds himself attracted to Kang-woo's wife, Tae-ju. Sang-hyun later relapses into his illness and wakes in need of shelter from the sunlight, having become a vampire. Sang-hyun soon finds himself drinking blood from a comatose patient. Aghast, Sang-hyun attempts to commit suicide, but finds himself irresistibly drawn to human blood. EV's symptoms return and only seem to go away when he drinks blood. Trying to avoid committing a murder, Sang-hyun resorts to stealing blood transfusion packs from the hospital. Tae-ju, who lives with her ill husband and overprotective mother-in-law Mrs. Ra, eventually begins an affair with Sang-hyun. However, when she discovers the truth about Sang-hyun, she retreats in fear. When Sang-hyun pleads with her to run away with him, she turns him down, suggesting that they kill Kang-woo instead. When Sang-hyun's superior at the monastery requests vampire blood so that his eyes may heal and he may see the world before dying, a disgusted Sang-hyun flees from the monastery. He moves into Mrs. Ra's house so that he may secretly have sex with Tae-ju. Sang-hyun notices bruises on Tae-ju and assumes that Kang-woo is the cause, a suspicion that she confirms. Sang-hyun decides to kill Kang-woo during a fishing trip with the couple. He pulls Kang-woo into the water and claims to his superior that he placed the body inside a cabinet in a house at the bottom of the lake, putting a rock on the body to keep it from floating to the surface. When Sang-hyun's symptoms return, he kills his superior and drinks his blood. A police investigation ensues. Mrs. Ra drinks often after Kang-woo's death, sinking into a completely paralyzed state. Sang-hyun and Tae-ju are haunted by visions of Kang-woo's corpse. When Tae-ju lets slip that Kang-woo never abused her, Sang-hyun is enraged because he only killed Kang-woo to protect her. Distraught, she asks Sang-hyun to kill her and let her return to Kang-woo. Sang-hyun kills her, but after feeding on her blood, decides that he does not want to be alone forever and feeds her corpse his own blood. She awakens as a vampire. Mrs. Ra, knocked to the floor by a seizure, witnesses everything. Tae-ju soon starts killing indiscriminately to feed, while Sang-hyun acts more conservatively, only killing when necessary. Their conflicting ethics result in a chase across the rooftops and a battle. Mrs. Ra eventually manages to communicate to Kang-woo's friends that Sang-hyun and Tae-ju killed her son. Tae-ju kills two of the friends, and Sang-hyun appears to eliminate a third one. Realizing the gravity of the situation, Sang-hyun tells Tae-ju that they must flee or be caught. Sang-hyun then places Mrs. Ra in his car and drives into the night with Tae-ju. Before leaving town, he makes a visit to the camp of people who worship him. He makes it seem like he tried to rape a girl, leading the campers to chase him away, no longer idolizing him. At the house, the third friend escapes; whom Sang-hyun only pretended to kill to protect her from Tae-ju. Meanwhile, Sang-hyun drives to a desolate field with no cover from the imminent dawn. Realizing his plan to have them both burn when dawn breaks, Tae-ju tries to hide but Sang-hyun foils her every attempt. Resigning herself to her fate, she joins him on the car hood, and both are burnt to ash by the sun, as Mrs. Ra watches from the backseat of the car.

In the early 1960s, a motown three-girl " Greek chorus " – Crystal, Ronette and Chiffon – introduce the film, warning the audience of some impending horror ("Prologue: Little Shop of Horrors"). Orphaned Seymour Krelborn and his co-worker, Audrey, work at Mushnik's Flower Shop in the rough, rundown Skid Row neighborhood of New York City, which they lament that they cannot escape ("Skid Row (Downtown)"). Struggling from a lack of customers, Mr. Mushnik decides to close the store, but Audrey suggests he may have more success by displaying an unusual plant that Seymour owns. Immediately attracting a customer, Seymour explains he bought the plant – which he dubbed "Audrey II" – from a Chinese flower shop during a solar eclipse ("Da-Doo"). The plant brings much business to Mushnik's shop but soon starts to wither. Seymour accidentally pricks his finger and discovers that Audrey II needs human blood to thrive ("Grow for Me"). Soon after, Audrey II begins to grow rapidly, and earns Seymour a spot on energetic DJ Wink Wilkinson's radio show, making him a local celebrity. Meanwhile, Audrey suffers at the hands of her sadistic and evil biker boyfriend, Orin Scrivello; however, she has feelings for Seymour and secretly dreams of being married and living happily with him in the suburbs ("Somewhere That's Green"). Seymour continues to feed Audrey II his own blood, draining his energy ("Some Fun Now"). He attempts to ask Audrey out, but she turns him down because she has a date with Orin, who is revealed to be a dentist who enjoys his patients’ misery ("Dentist!"). After Seymour closes up shop, Audrey II finally has a chance to speak to Seymour, demanding more blood than Seymour can give. The plant suggests that Seymour murder someone, promising to bring him fame and fortune that will impress Audrey. Seymour initially refuses but eventually agrees after he witnesses Orin physically and verbally abusing Audrey in the street ("Feed Me (Git It!)"). After Orin finishes with his masochistic patient, Arthur Denton, who had requested "a long, slow, root canal", Seymour draws a revolver on Orin, but cannot bring himself to use it. Orin, who abuses nitrous oxide, puts on a type of venturi mask to receive a constant flow of the gas, but breaks the valve, and Seymour watches as he asphyxiates. Seymour dismembers Orin's body and feeds it to Audrey II, which has grown to enormous size, but is unknowingly witnessed by Mushnik, who flees in fear. Audrey, feeling guilty over Orin's disappearance, is comforted by Seymour and the two admit their feelings for each other ("Suddenly, Seymour"). That night, Mushnik confronts Seymour about Orin's death. Holding Seymour at gunpoint, Mushnik threatens to turn Seymour over to the police but reconsiders and instead offers to stay silent and let Seymour flee Skid Row in exchange for the plant and its profits. As Audrey II opens its mouth to feed, Seymour begins to tell Mushnik how to care for the plant and backs him into the plant's reach. The plant swallows Mushnik whole ("Suppertime"). Despite widespread success, Seymour worries about Audrey II's growth and unbridled appetite ("The Meek Shall Inherit"). Torn between continuing his partnership with the plant and the thought of losing Audrey if he's no longer successful, Seymour becomes overwhelmed. Audrey congratulates Seymour on a contract for a botany TV show and tells Seymour the producers will return with the money the following day. Seeing a way out, Seymour proposes to Audrey, asking her to marry him that afternoon. He'll take the money in the morning and escape Skid Row with Audrey, leaving the plant to starve. After Audrey accepts Seymour's marriage proposal, Audrey II catches Seymour leaving and demands another meal: Seymour agrees but insists on meat from a butcher. While Seymour is gone, the plant telephones Audrey, coaxes her into the shop and attacks her ("Suppertime II").

In the Spanish countryside, a middle-aged man named Héctor and his wife Clara live in a home that they are renovating. Héctor scans the forest behind their house with binoculars and sees a young woman take off her T-shirt, exposing her breasts. When his wife goes shopping, he investigates and finds the woman on the ground, naked and unconscious. He is stabbed in the arm by a mysterious man with bloody bandages on his face. Fleeing and breaking into a mysterious nearby building, Héctor contacts a scientist by walkie-talkie, who warns him of the bandaged man and guides him to his location, promising safety. With the bandaged man just outside, the scientist convinces Héctor to hide inside a large mechanical device. When Héctor leaves the machine, he discovers that he has traveled approximately an hour back in time. The scientist explains that the machine is an experimental time machine and refers to Héctor as "Héctor 2". The scientist tells Héctor 2 that they need to stay where they are and let events unfold. Despite the scientist's warning, Héctor 2 drives off in a car, passing a cyclist, who he recognizes as the woman Héctor 1 saw in the forest. Héctor 2 chases the woman, only to be run off the road by a van, cutting his head, which he wraps using the bandage from his arm wound. He then realizes the bandaged man from before is himself. The woman approaches to see if he is all right. Héctor 2 replicates events by making the woman undress in view of Héctor 1. When she runs away, Héctor 2 catches her, inadvertently knocking her out. Héctor 2 lays her out naked on the ground and then stabs Hector 1 in the arm when he arrives. The woman escapes. Héctor 2 returns to his home, where he hears a scream and chases a woman through his house and onto the roof. When Héctor 2 attempts to grab her, she slips and falls to her death. Seeing the body from the roof, Héctor 2 is horrified, believing he has killed his own wife. Héctor 2 contacts the scientist over the walkie-talkie and convinces him to lure Héctor 1 to the lab with warnings that he is being pursued. Driving to the lab, Héctor 2 insists that he must travel back one more time, despite the scientist revealing that there is a Héctor 3, who told him he must stop Héctor 2 from doing just that. After removing his bandages, Héctor 2 convinces the scientist to send him back several seconds before Héctor 2 initially appears. This causes him to become Héctor 3, who uses a van to run Héctor 2 off the road, but crashes as well, knocking himself out. Upon waking, Héctor 3 informs the scientist he has failed to stop Héctor 2. Héctor 3 encounters the woman again, startling her into screaming, though she does not recognize him as her assailant. Since Héctor 2 has heard her scream, Héctor 3 and the woman flee to Héctor's house. They become separated. Héctor 3 finds and hides his wife, then realizes what has to happen / will happen / has already happened. He finds the woman, cuts her ponytail off, gives her his wife's coat and tells her to hide upstairs. Héctor 2 chases her onto the roof. Héctor 3 sits on his lawn with his wife as Héctor 2 accidentally kills the woman, then drives off – heading back to the lab to become Héctor 3. Emergency vehicles are heard approaching in the distance.

In 1971, Lucie Jurin escapes from a slaughterhouse where she has been imprisoned and tortured for over a year. She is placed in an orphanage, where she befriends Anna Assaoui. One day, Anna finds Lucie in a bathtub, her arm covered in cuts. Lucie begs Anna not to tell anyone. Anna embraces her, imploring her not to cut herself. Lucie responds that she did not do it. Later, Lucie is attacked by a disfigured, demonic woman. 15 years later, Lucie invades the home of a seemingly normal family, the Belfonds, whom she believes were involved in her torture as a child, and methodically kills each of them with a shotgun. She calls Anna and gives her the house's address. While waiting for Anna to arrive, the demonic woman attacks Lucie, stabbing her hand and cutting her back. Lucie flees the house and encounters Anna, who tends to her injuries and enters the house despite Lucie's warning not to. Anna is horrified by the carnage, but decides to help Lucie clean the crime scene and dispose of the bodies. Anna kisses Lucie, who rejects her. Lucie is once again attacked by the woman and hides with Anna in a bedroom. Lucie recalls her escape, during which she ran from a pleading fellow prisoner who begged her for help. Anna discovers the Belfond mother is still alive and tries to help her escape, but Lucie catches them and beats the mother to death with a hammer. The demonic woman again attacks Lucie, but Anna only sees Lucie hurting herself; the woman resembles the victim that Lucie left behind at the slaughterhouse and is a psychological manifestation of Lucie's guilt. Lucie then runs outside and kills herself by slitting her own throat. The following morning, Anna, while on the phone with her estranged, abusive mother, discovers a secret passageway in the home's living room, leading to a subterranean chamber containing illuminated photographs of torture, and a living, brutalized, emaciated woman, proving Lucie's claims about the Belfonds. Anna attempts to help the woman, who is hysterical and nonverbal. She removes a steel blindfold that has been stapled to the woman's skull and helps bathe her, only to later find her mutilating her arm with a knife. A group of people arrives at the house, kills the woman, and captures Anna. The group's leader, identified only as Mademoiselle, explains that they belong to a secret society seeking to uncover the secrets of the afterlife by creating " martyrs ". They capture individuals and inflict on them systematic acts of torture, believing that their physical suffering will result in transcendental insight into the world beyond. Though they have only produced "victims" who succumbed to the pain and were unable to speak, the group is determined to create martyrs who accept their suffering and report their visions of the afterlife. Anna becomes the group's newest subject. After a period of being brutally beaten and degraded, she is told that she has progressed further than any other subject and reached the "final stage", demonstrating her acceptance of her fate. She is surgically flayed alive and reportedly enters an " ecstatic " state. Mademoiselle arrives, eager to learn Anna's secrets, and Anna whispers into her ear. Members of the society gather at the house to pay veneration to Anna for her martyrdom and hear Mademoiselle's announcement of the groundbreaking testimony. While waiting for Mademoiselle, who is in the bathroom, Étienne, an assistant, asks her from outside the door if what Anna said was clear. She unequivocally confirms and asks him in turn if he can imagine what comes after death. After he says no, Mademoiselle produces a handgun, tells him to "keep doubting," and shoots herself. An intertitle explains that "martyr" is Greek for "witness". The film ends with a shot of Anna lying catatonic on a table, seemingly looking at something far away. During the credits, home movies of Anna and Lucie as children are shown.

Shy 17-year-old Noriko Shimabara lives with her younger sister Yuka, her mother Taeko, and her father Tetsuzo in Toyokawa, Japan. Unsatisfied with her small-town life, she hopes to move to Tokyo, especially when she learns that her childhood friend Mikan is now working independently as an idol. Tetsuzo disapproves of her ambitions and instead hopes she will attend a local university after high school. Noriko discovers Haikyo ("Ruins"), a website where other teenagers from Japan communicate. Feeling alienated and misunderstood by her parents, and encouraged by her new friends from the site, she runs away from home and travels to Tokyo. She meets Haikyo's leader, a 25-year-old woman named Kumiko who uses the screen name "Ueno Station 54," at locker 54 in Ueno Station. Kumiko introduces Noriko to her family and takes her to visit her grandparents, whom Noriko later learns are actually paid actors working for Kumiko's organization, I.C. Corp, which offers paid rental family services to clients. Abandoned as an infant, Kumiko has developed a nihilistic view of society, even coldly rejecting her birth mother's attempts to reconcile in Kumiko's adulthood, and founded I.C. Corp to allow lonely people to fulfill their fantasies of a happy family life. One of the I.C. Corp actors, Broken Dam, is hired by a man who wants her to act as his unfaithful wife so he can murder her. Broken Dam happily agrees, seemingly completely unfearful of death. Kumiko attends the session, and, impressed by Broken Dam's willingness to die for her role, orders 54 I.C. Corp actors to commit suicide by jumping in front of a train at Shinjuku Station. She makes Noriko witness the event, hoping Noriko will undertake an equally consequential task one day. Back in Toyokawa, Yuka, who is also a Haikyo user, speculates on whether her sister was involved in the mass suicide and how Tetsuzo would react if she were to disappear as well. Yuka runs away to Tokyo to join I.C. Corp, but deliberately leaves behind hints for Tetsuzo to find so he can ascertain what has happened to her. Taeko's mental state rapidly deteriorates in the wake of her daughters' absences, and she eventually commits suicide. Tetsuzo quits his job as a reporter to investigate his daughters' disappearances and sadly realizes that he was never supportive or aware of his daughters' feelings. Taking cues from sensationalist media tabloids, he comes across Haikyo and concludes that his daughters are part of a cult called the "Suicide Club". Tetsuzo contacts a member of I.C. Corp, who refutes the existence of a "Suicide Club" and instead expounds on a concept of social roles that forms the basis of the organization. Two years after Noriko and Yuka's departure, Tetsuzo convinces his friend Ikeda to pose as a client for I.C. Corp, renting Kumiko as his wife and Noriko and Yuka (who now go by the aliases Mitsuko and Yoko, respectively) as his daughters. Tetsuzo finds a house in Tokyo resembling the Shimabara family's and chooses it as the meeting site, moving all of their furniture into it. He hides in a wardrobe to observe as the session commences. Noriko and Yuka are unsettled upon arriving at the house, but fall back into their roles when prompted by Kumiko. After Ikeda sends Kumiko on an errand, Tetsuzo reveals himself, though the girls insist he is a stranger. Kumiko's bodyguards arrive and attack Tetsuzo, but he retaliates and fatally stabs them all. Kumiko returns shortly thereafter, initially continuing to act out her role as normal before imploring Tetsuzo to kill her and run away with Noriko and Yuka, whom she addresses by their real names for the first time despite Noriko's protests. A distraught Yuka asks to extend the session. Tetsuzo, Kumiko, Mitsuko and Yuka eat dinner together. Tetsuzo treats Kumiko as his wife, referring to her as Taeko. That night, Yuka leaves at the crack of dawn and walks toward the city center, deciding that she is done being Yoko, but is no longer Yuka either. Mitsuko awakens shortly thereafter and, speaking to herself, bids goodbye to Yuka, her youth, Haikyo, and Mitsuko, before finally declaring that she is Noriko.