Scenes that totally surprise a viewer — those can be great scenes. And memorable. I still remember when I watched Alien in a theater, leaping out of my seat when I first experienced this scene. I’ve included the preceding bit of business to warm you up.

INT. CORRIDOR OUTSIDE INFIRMARY WINDOW

What they see is...Not what they expect.Kane is sitting up in bed...wide awake.They enter...

LAMBERTKane...Are you all right.

KANEMouth's dry...can I have somewater.

Instantly, Ash brings him a plastic cup and water.Kane gulps it down in a swallow.

KANEMore.

Ripley quickly fills a much bigger container.Hands it to Kane.He greedily consumes the entire contents.Then sags back, panting, on the bunk.

DALLASHow do you feel.

KANETerrible.  What happened to me.

ASHYou don't remember.

KANEDon't remember anything.  I canbarely remember my name.

PARKERDo you hurt.

KANEAll over.  Feel like somebody'sbeen beating me with a stickfor about six years.(smiles)God, I'm hungry.

RIPLEYWhat's the last thing you canremember.

KANEI don't know.

DALLASDo you remember what happenedon the planet.

KANEJust some horrible dreamabout smothering.  Whereare we.

RIPLEYWe're on our way home.

BRETTGetting ready to go back intothe freezers.

KANEI'm starving.  I want some foodfirst.

PARKERI'm pretty hungry myself.

DALLASOne meal before bed.

INT. MESS

The entire crew is seated.Hungrily swallowing huge portions of artificial food.The cat eats from a dish on the table.

KANEFirst thing I'm going to do whenwe get back is eat some decentfood.

PARKERI've had worse than this, butI've had better too, if you knowwhat I mean.

LAMBERTChrist, you're pounding down thisstuff like there's no tomorrow.

Pause.

PARKERI mean I like it.

KANENo kidding.

PARKERYeah.  It grows on you.

KANEIt should.  You know what theymake this stuff out of...

PARKERI know what they make it out of.So what.  It's food now.  You'reeating it.

Suddenly Kane grimaces.

RIPLEYWhat's wrong.

Kane's voice strains.

LAMBERTWhat's the matter.

KANEI don't know... I'm getting cramps.

The others stare at him in alarm.Suddenly he makes a loud groaning noise.Clutches the edge of the table with his hands.Knuckles whitening.

ASHBreathe deeply.

Kane screams.

KANEOh God, it hurts so bad.It hurts.  It hurts.(stands up)Ooooooh.

BRETTWhat is it.  What hurts.

Kane's face screws into a mask of agony.He falls back into his chair.

KANEOhmygooaaaahh.

A red stain.Then a smear of blood blossoms on his chest.The fabric of his shirt is ripped apart.A small head the size of a man's fist pushes out.The crew shouts in panic.Leap back from the table.The cat spits, bolts away.The tiny head lunges forward.Comes spurting out of Kane's chest trailing a thick body.Splatters fluids and blood in its wake.Lands in the middle of the dishes and food.Wriggles away while the crew scatters.Then the Alien being disappears from sight.Kane lies slumped in his chair.Very dead.A huge hole in his chest.The dishes are scattered.Food covered with blood.

LAMBERTNo, no, no, no, no.

BRETTWhat was that.  What the Christwas that.

PARKERIt was growing in him the wholetime and he didn't even know it.

ASHIt used him for an incubator.

RIPLEYThat means we've got anotherone.

DALLASYeah.  And it's loose on theship.

Slowly they gather around Kane's gutted corpse.Then they all look at one another.Then at Kane.Dead on the table.

We’ve noted the writing style of Walter Hill here, here, and here. Although the movie’s official writing credits are “screenplay by Dan O’Bannon, story by Dan O’Bannon and Ron Shusett,” David Giler and Walter Hill contributed to the script and they both received a producer credit. Hill’s writing style is unmistakable and it’s in evidence here.

UPDATE: Just to be clear, while the above version of the scene’s writing style (scene description) may reflect something of Walter Hill’s influence, the scene’s concept and content originate from Dan O’Bannon’s initial draft of the script. That is made abundantly clear when you compare to O’Bannon’s version here:

INTERIOR - MULTI-PURPOSE ROOM

The entire crew is seated around the table, eating huge portionsgreedily.  The cat eats from a dish on the table.

HUNTERBoy do I feel a lot better.  It's astraight shot back to the Colonies,and then we can start taking bids onthe paydirt.  Any bets on the topbid?

FAUST(chewing)Well, we should at least be able toeach buy our own planet.

They all CHUCKLE.

MELKONISI'm going to write a book about thisexpedition.  I'm going to call it"The Snark Log."

STANDARD(stiffly)The commander normally has firstpublication rights.

MELKONISMaybe we could write it together.

ROBYFirst thing I'm going to do when weget back is eat some biologicalfood.

MELKONISWhat's the matter, you don't likethis stuff?

ROBYTastes like something you'd feed achicken to make it lay more eggs.

STANDARDOh it's okay.  I've had better cagthan this, but I've had worse too,if you know what I mean.

FAUSTI kind of like it.

ROBYYou like this shit?

FAUSTIt grows on you.

ROBYYou know what they make this stuffout of?

FAUST(annoyed)Yes, I know what they make it outof, so what?  It's food now.  You'reeating it.

ROBYI didn't say it was bad for you,it's just kind of sickening, that'sall.

HUNTERDo we have to talk about this kindof crap at the dinner table?

Suddenly, unexpectedly, BROUSSARD GRIMACES AND GROANS.

STANDARDWhat's wrong?

BROUSSARD(his voice straining)I don't know... I'm getting theseCRAMPS!

The others stare at him in alarm.  Another GROAN is torn from his lips.He clutches the edge of the table with his hands, his knuckleswhitening.

STANDARDBreathe deeply.

BROUSSARD(screaming)OH GOD IT HURTS SO BAD!

ROBYWhat Dell -- what?

Broussard's face is screwed up into a mask of agony, and he istrembling violently from head to foot.

BROUSSARD(incoherent shriek)OhmygooaaAAAHHHHH!!!

A RED SMEAR OF BLOOD BLOSSOMS ON THE CHEST OF BROUSSARD'S TUNIC.

THEIR EYES ARE ALL RIVETTED TO BROUSSARD'S CHEST AS THE FABRIC OF HISTUNIC IS RIPPED OPEN, AND A HORRIBLE NASTY LITTLE HEAD THE SIZE OF AMAN'S FIST PUSHES OUT.

Everybody SCREAMS and leaps back from the table.  The cat spits andbolts.

The disgusting little head lunges, comes spurting out of Broussard'schest trailing a thick, wormlike tail -- splattering fluids and blood-- lands in the middle of the dishes and food on the table -- andscurries away while the men are stampeding for safe ground.

When they finally regain control of themselves, it has escaped.Broussard lies slumped in his chair, a huge hole in his chest,spouting blood.  The dishes are scattered and the food is covered withblood and slime.

HUNTEROh, no.  Oh, no.

FAUSTWhat was that?  What the Christ wasthat?

MELKONISIt was growing in him the whole timeand he didn't even know it!

Slowly, they gather around Broussard's gutted corpse.

ROBYThat thing used him for anincubator!

[youtube=http://www.youtube.com/watch?v=1QPK-SNGn8I]