LAMBERT: I found it. Just short of Zeta II Reticuli. We haven't reached the outer rim yet.
KANE: That's hard to believe.
Fear of the unknown starts with an introduction to the unknown, and one of the best ways to find it is to get lost. Here, the crew of the Nostromo is stuck in a Scooby Doo-type situation, only instead of being lost in the bayou, they're lost beyond even the outer rim of the known universe.
LAMBERT: Let's get out of here.
KANE: We've come this far. We must go on. We have to go on.
People relate to the unknown in different ways. Lambert fears it while Kane embraces it. In an adventure science fiction story, this attitude would make Kane the hero of the story. But this is horror science fiction, so we're betting Lambert has the right idea here.
DALLAS: He could die in 24 hours. Open the hatch.
RIPLEY: Listen to me. If we break quarantine, we could all die.
LAMBERT: Would you open the goddamn hatch? We have to get him inside!
In horror, the unknown comes to scare in one of two ways: Either (1) the characters visit the unknown or (2) the unknown enters the house, town or other place of normality and safety. Alien, like Dracula, has it both ways. First the characters visit the unknown and then they bring something horrible back with them.
RIPLEY: What is the last thing you do remember?
KANE: I remember some horrible dream about smothering, and…. Anyway, where are we?
It's easy to see what happens to Kane as a type of terrifying intergalactic rape. Here, we see Kane suppressing the memories, trying minimizing the fear by not dwelling on the incident.
LAMBERT: No, not that way. The other way, Dallas!
When Dallas enters the air ducts, every character reacts to fear in different ways: from Ripley's calm inward worry to Lambert's extroverted hysterics, Parker's fiery anger to Dallas's cool demeanor melting away. In one scene, we can view the myriad ways fear can affect various people.
Us? We'd probably be cowering behind Lambert.
ASH: There is an explanation for this, you know.
RIPLEY: There is? I don't want to hear your goddamn explanation! I don't want to hear. I don't want to hear. I…
We've talked a lot about the fear of the unknown, but here fear is found in the truth. Ripley put her well-being in the Company's hands, and it instead used her life as a down payment for a potential bio-weapon. The known can be just as a terrifying thing to encounter in Alien as the unknown.
RIPLEY: You… Are my lucky star… You, you're my lucky star. You are my lucky star. Oh, God!
This scene shows Ripley conquering her fear in a subtle way. Alone and stripped down to her shirt and underwear, Ripley is at her most vulnerable. Then, conquering her fear with the help of Singing in the Rain, Ripley armors herself with spacesuit and grappling hook and goes out to do battle with the beast.