INT: BESPIN GANTRY - MOMENTS LATER:
A furious lightsaber duel is underway. DARTH VADER is backing LUKE SKYWALKER towards the end of the gantry.
A quick move by Vader - he chops off Luke's hand! It goes spinning off into the ventilation shaft.
Luke backs away. He looks around, but realizes there's nowhere to go but straight down.
Darth Vader: Obi Wan never told you what happened to your father.
Luke: He told me enough! He told me you killed him!
Darth Vader: No... I am your father!
Luke: No, it's not true! It's impossible.
Darth Vader: Search your feelings... you know it to be true...
Darth Vader: Yes, it is true... and you know what else? You know that brass droid of yours?
Darth Vader: Yes... Threepio... I built him... when I was 7 years old...
Darth Vader: Seven years old! And what have you done? Look at yourself, no hand, no job, and couldn't even levitate your own ship out of the swamp...
Luke: I destroyed your precious Death Star!
Darth Vader: When you were 20! When I was 10, I single-handedly destroyed a Trade Federation Droid Control ship!
Luke: Well, it's not my fault...
Darth Vader: Oh, here we go... "Poor me... my father never gave me what I wanted for my birthday... boo hoo, my daddy's the Dark Lord of the Sith...waahhh wahhh!"
Luke: Shut up...
Darth Vader: You're a slacker! By the time I was your age, I had exterminated the Jedi knights!
Luke: I used to race my T-16 through Beggar's Canyon
Darth Vader: Oh, for the love of the Emperor... 10 years old, winner of the Boonta Eve Open... Only human to ever fly a Pod Racer... right here baby!
Luke looks down the shaft. Takes a step towards it.
Darth Vader: I was wrong... You're not my kid... I don't know whose you are, but you sure ain't mine...
Luke takes a step off the platform, hesitates, then plunges down the shaft.
Darth Vader: (Yelling after him) Get a haircut!