Hayden Christensen stars as Anakin Skywalker, a Jedi who turns to the dark side in the new “Star Wars: Episode III — Return of the Sith.”

The magic is back.

George Lucas’ spectacular “Star Wars: Episode III – Revenge of the Sith,” which opens in theaters worldwide a week from today, recaptures the high-energy fun that made this series so popular in the first place. It’s the best episode after “A New Hope” and “The Empire Strikes Back.”

Providing a bridge between Lucas’ prequels and his beloved original trilogy, this chapter sheds light on why Anakin Skywalker became Darth Vader.

In the thrilling opening sequence, Jedi fighters battle Separatist droids above the city-planet of Coruscant. There’s an interactive feel to the whizzing ships and dogfight aerial maneuvers as Anakin and Obi-Wan Kenobi race to rescue Chancellor Palpatine from the clutches of the evil General Grievous. Count Dooku also returns in a scene that mirrors the climax of “Return of the Jedi” and sets a course for Anakin’s seduction by the dark side of the Force.

General Grievous is one of two super villains who dominate “Revenge of the Sith.” A human-robot hybrid with a hunchback and a terrible cough, this computer-generated baddie should join the ranks of such series favorites as Jabba the Hutt and Boba Fett.

But the real star of the show is Ian McDiarmid as Palpatine, who offers such dubious advice as, “Good is a point of view, Anakin.” McDiarmid exudes operatic evil in a succession of atmospheric scenes that are among the darkest of the saga. His transformation from the soft-spoken chancellor to the cackling, ashen-faced emperor is absolutely chilling.

As Anakin, Hayden Christensen is less whiny and more brooding this time around. When freed from the constraints of romantic melodrama, Christensen shows real acting chops. Ewan McGregor also fares better, finally coming into his own in the long shadow of Alec Guinness’s original Obi-Wan.

Overall, the film represents a triumphant comeback for Lucas, who seems intent on playing out the wildest fantasies of the Jedi faithful.

Obi-Wan squares off against General Grievous, who can wield four lightsabers with two sets of robotic hands.

Anakin and Obi-Wan clash in an exhilarating duel on the volcanic planet of Mustafar. And when Anakin finally catches that first breath of mechanically-filtered air through the mask of Darth Vader, it’s not just a great “Star Wars” moment. It’s an all-time great movie moment.

“Revenge of the Sith” isn’t entirely devoid of the problems that plagued “The Phantom Menace” and “Attack of the Clones.” Christensen and Natalie Portman suffer through a few early scenes. But the artificial tone of the previous episodes is gone. This is an action-packed, emotionally-rich and thematically-ambitious piece of cinema.

It’s also the culmination of a life’s work for Lucas, who evidently still has a few surprises left in him. His film isn’t perfect, but it’s everything “Star Wars” fans hoped it would be.

— Edited by Jennifer Voldness