While Luke Skywalker was finished recovering. He saw as he was being held bclose to his father side as he heard the words he knew he hear sooner or later. "Commander get the army ready." At this point Luke saw that his friends where being held captive by an bunch of stormtroopers. He knew why Leia, Han, Wedge, and Chewbacca where escapeing. they wanted there friend to not be hurt. But the way things looked. He would never get hurt if his father had things. He had to do something his friends where not to be killed on Luke's watch
Now Darth Vader was not surprised by his son's word's " Father please spare them my friends they just do not want to see me corrupted by the dark side." Luke was right. Darth Vader agreed to his Son's words he definitely had a lot of Padme. Now the sith lord to let some of the most of the leaders and rebal soldiers live. His master would never have the Luke. His son was to important to him.
Now Luke was next to his father in an imperial shuttle. He was bit sleepy his visions of late where of tpye of draining him of sleep. He was just happily sleeping in the chair next to Vader's. He was aafe his friends for the better part where safe. Ben was not totally lying to him. But still all this to find out your dad is Darth Vader.
Now Vader killed any witnesses of anything about Luke in the Empire. He was going to have Luke. Their was an dragon like greed in the sith action. He would see the end of Palpatine. He would have his son. No matter what.