In the Making of The Empire Strikes Back, Vader was supposed to kill Luke Skywalker through the force, telepathically. They were supposed to fight on what becomes Hoth, and in this first draft, Vader isn't Luke's father. He's the guy who killed Anakin Skywalker.
R2 saves Luke, again, and blasts off into hyperspace, where Luke was able to breathe again from the force choke.
Luke then goes to meet Minch Yoda.
Learn more about your ad choices. Visit megaphone.fm/adchoices