Alien is a science-fiction horror/action media franchise centered on the film series depicting warrant officer Ellen Ripley (Sigourney Weaver) and her battles with an extraterrestrial lifeform, a "xenomorph" commonly referred to as "the Alien". Produced and distributed by 20th Century Fox, the series began with Alien (1979), directed by Ridley Scott, and was followed by three sequels, Aliens (1986), Alien 3 (1992), and Alien Resurrection (1997), directed by James Cameron, David Fincher, and Jean-Pierre Jeunet, respectively.
Scott also directed a prequel series, composed of Prometheus (2012) and Alien: Covenant (2017), which follows the exploits of the David 8 android and the creators of the titular creatures referred to as the "Engineers". The series has led to numerous novels, comics, and video game spin-offs.
The plot of the Alien franchise movies is extensive and expansive, but most would agree that the original Alien trilogy was the best, and retains a solid sense of nostalgia when viewed today. The story of the original series focuses on Ellen Ripley's struggle for survival against the Aliens, alongside several groups of comrades, while also preventing Weyland-Yutani from obtaining the creatures. After sacrificing herself, Ripley returns two hundred years later as a human-Alien hybrid clone called Ripley 8, retaining genetic memory, but with a different personality and superhuman abilities.
In the first film, on its way back to Earth, the commercial spaceship USCSS Nostromo is diverted to a desolate planetoid by a cryptic signal from a derelict alien spacecraft. While exploring the alien ship, one of the Nostromo's crewmen discovers the remains of the ship's pilot and also a large chamber that contains thousands of egg-like objects. One of the eggs releases a creature that attaches itself to his face and renders him unconscious. The others break quarantine to bring him back aboard the ship. The parasite dies and the crewman wakes up, seemingly fine. Soon afterwards, an alien organism bursts from his chest and grows extremely rapidly into a terrifying eight-foot (about 2.5 meters) tall creature that starts killing off the crew. Ellen Ripley is the only survivor.
After 57 years in hypersleep, the sole survivor of the USCSS Nostromo, Ellen Ripley, awakens aboard a medical space station orbiting Earth. Her story of the Alien terror she encountered is disbelieved and she learns that the planetoid from the first film (now designated as LV-426 or Acheron) is now home to a terraforming colony. When contact with the colony is lost, Ripley, against her better judgment and to regain her pilot's license, hesitantly accompanies a squad of high-tech Elite Colonial Marines aboard the spaceship USS Sulaco to investigate. Once there, they discover the colonists have been wiped out after finding the derelict alien ship (and its deadly cargo) from the first film. Ripley is one of only 3 survivors to get out alive, and they shoot themselves off into hyperspace after blowing up the planet. They on the refinery/prison planet Fiorina "Fury" 161, but Ripley is the only one to survive the crash. Unbeknownst to her, an Alien Facehugger was also aboard the ship. Before long, a full-sized Alien is then loose in the prison, killing the inmates and staff. Ripley also discovers there is an Alien queen growing inside her, and must not only kill the rampaging Alien but also herself in order to save humanity.