Released in 1979, Alien is the horrific sci-fi tale about an unfriendly, not-so-little-nor-green creature that comes aboard Nostromo, a commercial tanker, and begins stalking the crew. But the skin-crawling alien notwithstanding, the film's most intense "other-worldly" sequence might be the crew's battle against Ash (Ian Holm). He's the ship's Science Officer, and, as it turns out, an android secretly ordered to ensure the organism's return to Earth. The exact verbiage of the command is chilling: "Crew is expendable." His forehead secreting what looks like wax, Ash advances upon Ripley (Sigourney Weaver), to kill her before she informs the crew of the command. Brute robotic strength overtakes his arms. When Parker (Yaphet Kotto) clobbers Ash from behind, the latter's split ribcage spews a thick white paste, and a mainframe, wires shredded, dangles from his chest. Glowing yellow pustules lash out from what was Ash's spine. After surviving the attack Ripley rewires Ash to question him. Calm and unemotional, Ash explains that he admires "the organism's purity," which is a statement I won't be forgetting anytime soon.