The third part of the notorious space epic details the final stages of Anakin Skywalker's life before his cross into the Dark Side. The Galactic Republic has been seriously debilitated during the Clone Wars. Anakin and Obi-Wan Kenobi are about to infiltrate General Grievous's ship to rescue Chancellor Palpatine, where they are caught in a lightsaber duel with Count Dooku, who Anakin kills. When Grievous flees, the two Jedi crash-land the ship on Coruscant, where Anakin sees his pregnant wife Padmé Amida. Despite a premonition that she will die in labor, he is happy to see her.
Palpatine decides to put Anakin on the Jedi Council as his representative, but Anakin is denied Jedi Master and is instead assigned to track Palpatine. Just as he starts to lose faith in the Jedi Council, he discovers that Palpatine is Sith Lord Darth Sidious. Though he reports the treason to Jedi Master Mace Windu, he then helps Sidious to defeat him. In return, Darth Sidious makes Anakin his apprentice, renaming him Darth Vader. Knowing that the Dark Side has power to prevent death, this appeals to Anakin's desperation to save his wife. Darth Sidious commands the Clone Troopers to kill their Jedi Masters, and sends a small troop of them with Vader to kill everyone at the Jedi Temple as well as the Separatists. Then Sidious renames the Republic the Galactic Empire, and declares himself Emperor.
When Obi-Wan and Yoda learn of Anakin's betrayal, they split up to find both him and Darth Sidious, taking Padmé with them, who won't be convinced he isn't still good. A struggle between Obi-Wan and Vader leaves Vader crippled and left for dead, though he is later revived and rebuilt cybernetically by Darth Sidious. While Vader is overseeing the construction of the Death Star, Padmé dies bearing twins Luke and Leia. The twins are separated, Luke to Tattooine and Leia to Alderaan, where they are raised separately.