Lando and the Rebel fleet keep fighting—and hoping that Han comes through and deactivates the shield.
Inside the shield bunker, the Imperial dudes get a video message from a stormtrooper outside who reports that the Rebels on Endor have been successfully squashed, and now they need backup. Backup is sent.
Cut to outside the bunker. The giddy Imperial backup troops come bounding out, practically skipping. Suddenly, they're surrounded on all sides by Ewoks. Han looks at them, shrugs, and smiles.
Inside the bunker, Han starts setting up explosive charges.
Darth Vader looks for Luke on the Death Star. He's hiding.
Once again, Darth Vader tells Luke to give in to the Dark Side. He says it's the only way he can save his friends, and that he knows Luke's thinking about it.
Then he reads Luke's mind, and deduces that Luke has a twin sister. He says that Obi-Wan was smart to hide her from him. If he can't turn Luke, he'll turn Leia. Also, he notes that Obi-Wan's basically a total failure now. Ouch.
When Darth Vader threatens to turn Leia to the Dark Side, Luke screams, "Never!" and attacks Vader. It just got real, y'all.
Luke and Darth Vader continue battling. Luke herds Vader to a bridge, where he gets the upper hand. Literally. Luke hacks off Darth Vader's right hand.
The Emperor starts laughing and congratulates Luke. He says his hate has made him powerful. Now, he should finish off Darth Vader and take his dad's place at the Emperor's side.
Luke looks at his robotic right hand, and then down at where his father's robotic right hand used to be. You know, before he chopped it off. Is he really turning into his dad and embracing the Dark Side like a warm and totally evil cup of tea?
Nope, Luke turns off his lightsaber and informs The Emperor that he'll never turn to the Dark Side. Never ever. He's a Jedi. Just like his dad.