Plot Summary (Alien) Alien (1979)

The Nostromo's crew wakes up halfway home because the Company rerouted them

The commercial towing vessel Nostromo is hauling twenty million tons of mineral ore back to Earth.^b1 Its seven-member crew — Captain Dallas, Executive Officer Kane, Warrant Officer Ripley, Science Officer Ash, Navigator Lambert, and Engineers Parker and Brett — wake from hypersleep to discover they are not near Earth.^{b1 b3} The ship's computer, Mother, has intercepted a transmission of unknown origin from a nearby planetoid, LV-426, and per company protocol the crew is contractually obligated to investigate.^b3 Parker objects — they are a commercial crew, not a rescue team — but Ash cites the penalty clause: failure to investigate means total forfeiture of shares.^b3 (wikipedia, imdb)

The landing strands them and Dallas leads an expedition to the signal source

The Nostromo detaches from its ore refinery and descends through LV-426's hostile atmosphere.^b5 The landing is rough — hull damage grounds the ship for at least seventeen hours while Parker and Brett make repairs.^b6 Dallas, Kane, and Lambert suit up and trek across the windswept surface toward the signal source.^{b7 b8} They find a massive derelict spacecraft of clearly non-human origin.^b8 Inside, they discover the fossilized remains of a giant alien pilot — the "Space Jockey" — with a hole burst outward from its chest.^b9 Below the pilot chamber, Kane descends into a vast cargo hold filled with rows of leathery eggs.^b10

Kane is attacked, and Ripley's first command decision is overruled

One of the eggs opens and a creature — the facehugger — launches itself onto Kane's helmet, melts through the visor with acid, and attaches to his face.^b10 Dallas and Lambert carry Kane back to the Nostromo.^b11 Ripley, in command aboard the ship, refuses to open the airlock — quarantine protocol requires a twenty-four-hour decontamination period, and she will not risk the ship.^b11 Ash overrides her and opens the inner hatch, letting the expedition party inside.^b11 This is the film's first major breach of protocol: the science officer has broken the chain of command, and the warrant officer who enforced the rules has been ignored.

The facehugger detaches, Kane seems fine, and something is wrong with the blood

Dallas and Ash attempt to remove the facehugger surgically. When they cut into one of its fingers, it bleeds molecular acid that eats through two decks of hull plating.^b12 They cannot remove it without destroying the ship.^b12 Hours later, the facehugger detaches on its own and is found dead.^b14 Kane wakes up feeling fine and hungry.^b16 The crew gathers for a meal before re-entering hypersleep.^b16

The chestburster kills Kane at dinner

During the meal, Kane begins convulsing. His crewmates hold him down on the table. An infant alien — the chestburster — erupts from his chest, screams, and scurries away into the ship.^b16 Kane is dead. The creature has used his body as an incubator and is now loose somewhere in the Nostromo's labyrinthine corridors.

"What you see on film is their genuine surprise and horror!" — Ridley Scott, on the cast's reaction to the chestburster, Scraps from the Loft (2019)

The crew hunts the alien and the alien hunts them back

Dallas improvises weapons — cattle prods, motion trackers, flamethrowers.^b17 Brett is killed first: while searching for the ship's cat, Jones, in the landing gear bay, the now fully-grown alien drops from the ceiling and takes him.^b19 Dallas enters the air shafts to flush the creature toward an airlock.^{b20 b21} Lambert tracks its position on the motion tracker.^b21 The alien does not flee — it turns and takes Dallas.^b21

Ripley discovers the Company wanted the alien all along

With Dallas and Kane dead, command falls to Ripley.^{b21 b22} She accesses Mother and discovers Special Order 937: "Investigate life form. Gather specimen. Priority one. Insure return of organism for analysis. All other considerations secondary. Crew expendable."^b23 The Company knew about the signal. It sent them to retrieve the alien. Ash was placed aboard to ensure the order was carried out. The system Ripley trusted — the chain of command, the contract, the science officer, the computer — was designed to sacrifice her crew.

Ash reveals himself and is destroyed

Ripley confronts Ash.^b24 He attacks her, attempting to kill her by forcing a rolled-up magazine down her throat.^b24 Parker intervenes with a fire extinguisher,¹ knocking Ash's head off — revealing him as an android.^b24 They reattach Ash's head and interrogate him.^b25 He expresses admiration for the alien — "a perfect organism, its structural perfection matched only by its hostility" — and tells them their chances of survival are negligible.^b25 They burn him.^b25

Lambert and Parker die, and Ripley is alone

Ripley decides to set the Nostromo's self-destruct sequence, escape on the shuttle Narcissus, and blow the ship.^b26 While Lambert and Parker gather coolant supplies for the shuttle, the alien finds and kills them both.^{b27 b28} Ripley hears their deaths over the intercom.^b28 She is now the sole surviving human crew member.

Ripley activates the self-destruct and barely makes it to the shuttle

Ripley activates the self-destruct countdown, grabs the cat, and runs for the shuttle.^{b29 b32} She encounters the alien blocking her path, reverses course to abort the self-destruct, but the override window has passed.^b31 She runs back, finds the corridor clear, and reaches the Narcissus. She launches just before the Nostromo detonates in a massive explosion.^b32

The alien is on the shuttle

In the Narcissus, Ripley prepares for hypersleep.^b33 She discovers the alien has stowed away in the shuttle's machinery.^b33 Moving carefully, she puts on a spacesuit,^b34 straps herself in, and blows the shuttle's hatch, venting the alien into space.^b35a It clings to the exterior. She fires the shuttle's engines, incinerating it.^2b35b She records a final log entry — "This is Ripley, last survivor of the commercial starship Nostromo, signing off" — and enters hypersleep with Jones the cat.^{b36 b37}