Now older, Luke is just a moisture farmer's boy with no idea of his backstory. Padme dies in childbirth and her twins, Luke and Leia are separated and hidden from the now-Empire, with Leia going to Alderaan and Luke ending up on Tatooine, with Obi-Wan going into exile there to watch over the boy. The Chancellor saves him, puts him in Darth Vader's famous black suit and they start the Death Star. Obi-Wan tries to stop him with an epic lightsaber battle on the molten planet Mustafar, leaving Anakin next to a lava river as little more than a burnt up torso. He also orders him to kill everyone, including younglings, though a few Jedi, including Yoda, escape. The Chancellor makes Anakin his apprentice and dubs him Darth Vader. Anakin eventually figures out that the Chancellor is a Sith Lord, but when the Jedi try to arrest him, Anakin comes to his aid because he still wants to save Padme from the visions of death.
He also brags to Anakin that he knows how to harness the dark side to cheat death - though you can't learn that from any (dismissively) Jedi. The Council declines to elevate him to Master status, so the Chancellor puts him on the Jedi Council as his representative (spy). Anakin is dealing with his demons, including visions of Padme dying in childbirth. The Chancellor, seeking to draw out Anakin's dark side, demands that Anakin assassinate Dooku, which he does. The Chancellor has been captured by a revolt leader General Grievous, but Obi-Wan and Anakin rescue him heroically.
The movie ends with the revelation that Dooku, the revolt, the clones and the droids are all being controlled by an evil Sith Lord - who is actually the Chancellor! Under pressure, the Galactic Senate votes the Chancellor emergency powers, which (wait for it!) is also a trap! The two armies battle and the Jedi and the Clones barely win. The full-scale revolt against the Republic is being led by Count Dooku, a former Jedi, who has built his own droid army.
Meanwhile, Anakin's mom is murdered and he freaks out, channeling the dark side that everyone knows he has in him. He also has no idea why the Jedi have ordered up a clone army. Meanwhile, Obi-Wan discovers that a Jedi master has ordered the creation of an army of clones based on a single bounty hunter, Jango Fett, whom Obi-Wan determines is the assassin trying to kill Padme - though he does not know why.
Anakin is assigned to protect Republic loyalist Sen. The weird trade dispute has grown to a full-scale revolt against the Republic. Anakin is older now, but just as bad an actor.