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.

Elizabeth McGraw, a young employee at a SoHo art gallery, meets John Gray, a Wall Street arbitrageur, at a Chinese grocer, and later at a flea market where he buys her an expensive shawl. They start dating, but John's strange behavior escalates, and he gives her an expensive gold watch with instructions to think about him touching her at noon every day. Elizabeth masturbates at work at the designated time. Elizabeth wants to introduce John to her friends, but he only wants to see her in the evenings and tells her to see her friends during the day. One evening, she is alone in his apartment and finds a photo of him with another woman. When John calls and asks if she went through his things, she admits it. He threatens to punish her, and returning home, he orders her to face the wall for a spanking. Elizabeth tries to leave, but the door is locked. John slaps her, she slaps him back and hits him repeatedly, and he has aggressive sex with her. Despite this, Elizabeth falls in love with John and starts to enjoy his dominant behavior. John takes control of all aspects of Elizabeth's life, from what she wears and eats to how he brushes her hair and feeds her. Elizabeth becomes increasingly dependent on John, losing her sense of self. One day, she follows John to work and brings him lunch, telling him she wants to be "one of the guys". John arranges for her to cross-dress for a rendezvous at a bar at the Algonquin Hotel, but after they leave, they are mistaken for a gay couple and attacked by a group of thugs in an alley. Elizabeth stabs one of the attackers in the buttocks, and they flee. Aroused by the incident, Elizabeth declares her love for John, takes off her dinner suit and has sex with him under a leaking drainpipe. John starts to make their BDSM -style relationship more apparent in public. He dares her to shoplift a necklace, and she does so. At the bedding section in Bloomingdale's, he asks Elizabeth to "spread your legs for daddy" in front of the saleswoman. At an equestrian store, he whips Elizabeth on the leg with a riding crop, which he buys. Later that evening, Elizabeth performs a striptease with the crop at John's apartment. One day, John asks Elizabeth to crawl and pick up money as he throws it on the floor of his apartment. Elizabeth initially obliges but then objects, and John threatens to hit her with his belt. Elizabeth cries and protests, but John continues to insist that she crawl and pick up the money. She eventually does so before throwing the money in John's face and declaring that she hates the game. Elizabeth feels confident at home with John, but she becomes withdrawn at work and thinks about her ex-husband Bruce, who starts dating her co-worker and roommate Molly. She goes to the countryside to visit an elderly artist named Matthew Farnsworth and secure an exhibit. Elizabeth meets John at a room at the Hotel Chelsea and is asked to wear a blindfold. John touches her briefly before a South American prostitute enters the room and caresses Elizabeth as John observes. Elizabeth becomes nervous, and the prostitute removes her blindfold. When John takes the prostitute to the next room and starts undressing her, Elizabeth hits him and flees. John follows her to an adult entertainment venue where Elizabeth starts kissing the man next to her during a live sex show. John approaches her, and they embrace. Elizabeth's gallery hosts a successful opening featuring Farnsworth's work. Farnsworth, uncomfortable with the partying crowd, finds Elizabeth in tears in a corner. She spends the night with John, but the next morning, she prepares to leave him. John tries to convince her to stay by telling her about his family and confessing his feelings, but Elizabeth responds that he knew their affair would end "when one of us said stop". As she leaves his apartment, John says he hopes she will return by the time he counts to 50. Elizabeth instead walks away through the crowded streets, crying.

After residents of a Paris apartment building complain of a smell coming from one of the apartments, the emergency services break down its door to find an elderly woman's corpse in the bedroom, adorned with cut flowers. Several months before the opening scene, Anne and her husband Georges, both retired piano teachers in their eighties, attend a performance by one of Anne's former pupils, Alexandre. They return home to find that someone has unsuccessfully tried to break into their apartment. The next morning, while they are eating breakfast, Anne silently has a stroke. She sits in a catatonic state, not responding to Georges. She comes around as Georges is about to get help, but has no idea the stroke occurred. Georges is unable to persuade her to get medical attention until Anne finds she is unable to pour herself a drink. Anne undergoes surgery on a blocked carotid artery, but the surgery goes wrong, leaving her paralyzed on her right side and reliant on a wheelchair. She makes Georges promise not to send her back to the hospital or to a nursing home. Georges becomes Anne's dutiful, though slightly irritated, caretaker. One day, Anne, seemingly having attempted to commit suicide by falling from a window, tells Georges she doesn't want to go on living. Alexandre, her former pupil whose performance they attended, stops by and Anne gets dressed up and carries on a lively conversation during the visit, giving Georges hope that her condition was temporary. But she soon has a second stroke that leaves her demented and incapable of coherent speech. Georges continues to look after Anne. Georges begins employing a nurse three days a week. Their daughter, Eva, wants her mother to go into care, but Georges says he will not break the promise he made to Anne. He employs a second nurse, but fires her after he discovers she is mistreating Anne. One day, Georges sits next to Anne's bedside and tells her a story of his childhood, which calms her. As Anne closes her eyes, he quietly picks up a pillow and smothers her to death. Georges returns home with bundles of flowers in his hands, which he proceeds to wash and cut. He picks out a dress from Anne's wardrobe and writes a long letter. He tapes the bedroom door shut and catches a pigeon that has flown in through the window. In the letter, Georges explains that he has released the pigeon. Georges imagines that Anne is washing dishes in the kitchen and, speechless, he gazes at her as she cleans up and prepares to leave the house. Anne calls for Georges to bring a coat, and he complies, following her out of the door. The film concludes with a continuation of the opening scene, with Eva seated in the living room after wandering around the now-empty home.

In late 1969, helicopter pilot Billy Covington has his pilot's license suspended for breaking safety regulations. His skills, bravery and disregard for the law are noticed by a government agent, who offers him a job in Laos working for the "strictly civilian" company Air America, which turns out to be a front for CIA operations. In Laos, he is introduced to Air America's unorthodox pilots and aircraft, being taken under the wing of pilot Gene Ryack, who uses official flights to buy black market weapons for his private cache. Senator Davenport arrives to investigate rumors that Air America is transporting drugs for Laotian forces. Major Lemond and Rob Diehl, CIA leaders of Air America, show the Senator around Laos to prevent him discovering that the rumors are true. Unfortunately, Davenport loses great respect from General Soong during their first meeting at the airport when mistaking him to be a local luggage-carrying valet. Soong holds this over Davenport's head for the remainder of his visit. While airdropping livestock in their C-123 cargo aircraft, Billy and Jack Neely are shot down, but Billy manages to crash-land the C-123 at a former World War II Japanese airstrip. The Pilatus PC-6 of General Soong arrives at the crash site and his soldiers load up with the opium from the crashed plane, but intentionally leave Billy and Jack behind while local Communist forces are moving in. Gene and another pilot rescue them; Billy boards Gene's helicopter. Billy and Gene are shot down after a short time in the air and captured by a tribe. Gene strikes a deal to supply them with better weapons. At Gene's house, Billy is surprised to discover that Gene has a wife and children. Disillusioned with U.S. actions in Laos, Gene convinces Billy to quit his job, but Billy wants to get even with General Soong. Davenport is losing patience and demands to know who is smuggling heroin. Learning that Jack has been killed, Lemond and Diehl claim he was the ring leader behind the drug trafficking. Billy blows up the heroin factory, but guards see him running away. Davenport demands more concrete evidence. Gene finds a buyer for his arsenal, allowing him to quit Air America and take his family out of Laos. Billy accepts one more flight, taking flour to a refugee camp when he is instructed to divert for "routine inspection." Suspecting a setup, Billy inspects the cargo and finds heroin. He crash-lands on the same airstrip where he crashed earlier and uses the wreckage of the previous crash to hide the aircraft. Davenport recognizes the nature of the setup and threatens to reveal Lemond and Diehl's operation to Washington. Major Lemond in return silences Senator Davenport by daring him to say what he thinks he saw in Laos but reveals that his own political connections involving a friendship with the President would only ruin Davenport's political career. Gene, on his way to make his final weapons delivery, rescues Billy. They respond to a distress call from a refugee camp caught in crossfire. The official in charge of the camp refuses to leave without the refugees. Gene reluctantly dumps the weapons to make room for the refugees, with much pressure from Billy, and blows up their cache to cover the escape. In the air, Gene and Billy hatch a scheme to sell the aircraft to recoup Gene's money. In the postscript of the closing credits, it is revealed that General Soong makes it to America eventually and gets his dream of owning and operating a Holiday Inn, that Gene wins a lottery in Thailand in 1975, and that Billy is deported from Thailand for fixing the same lottery in order for Gene to win.