Chapter 4 - Palpatine: Possession
The Emperor was on his feet, hearing the violent clashing from underneath the main audience chamber, feeling the power of the Dark Side in the boy. Highly amused, he wondered if the boy was so blind with rage and power that the entire throne room bridge was going to come down underneath him.
As father and son emerged from the underside of the throne room, Palpatine watched partly in excitement and partly in fear as the enraged young pupil turned on his old apprentice. This was not exactly as he foresaw things, but then, Vader was foolish to provoke his son. Now Palpatine sensed that Vader himself was emotionally unbalanced by the fact that his own son had turned on him. As they emerged, though, he noticed that Vader was not fighting with the correct stance.
Vader was being knocked backward by Skywalker, blow by blow.
Fool, he thought to himself happily. What did you expect? Your son inherited the same weakness from you that made you so easy to turn. I knew you would never be rid of your need for this pitiful side of yourself. Your pathetic ambition for this child has clouded your vision. If you cannot bring yourself to destroy him, then you are no longer worthy to be my apprentice.
Palpatine watched joyfully as Luke drove Vader back, Vader parrying the blows but being cut off at every chance, every move. Luke closed in on him as Vader stumbled to the floor. Skywalker released his anger by swinging his blade six times in a row at Vader - and when at last Vader no longer fought back - Luke disarmed his opponent by severing his hand at the wrist. Vader's mechanical hand and lightsaber fell end over end into the reactor shaft. Palpatine began to laugh loudly at the sight before him.
Now, Skywalker would surely be his.