...Darth Vader turns to find Emperor Plapatine behind him.
"I sense a disturbance Darth. There is evil intentions in you and those Stormtroopers there. There is an anger in you that the force can draw power from. This is good Darth. You will once again become a strong power. I wish to help you in your cause however tell me, what has brought this anger to you?"....
The rest of the story can be found:-