The Faithful (and quite a few of the Unfaithful) have been waiting a long time, enduring the bitter disappointment of "The Phantom Menace" and "Attack of the Clones," to get to this pivotal moment: to see how and why Anakin Skywalker (Hayden Christensen), the Chosen One, abandons his Jedi legacy, embraces the Dark Side and turns into Darth Vader.

Almost 90 minutes of the sixth and concluding film--"Star Wars Episode III: Revenge of the Sith"--go by before Anakin's final metamorphosis actually begins. First up, we are served a fairly rousing if madly busy aerial battle in which Anakin and his mentor, Obi-Wan Kenobi (Ewan McGregor), fight off crablike flying Droids in their attempt to rescue Supreme Chancellor Palpatine (Ian McDiarmid) from the clutches of General Grievous. Before the movie gets good--and it does, in the final 45 minutes, achieve a genuine dark power--we also have to put up with the usual Lucas liabilities: graceless dialogue, wooden acting, overcluttered compositions and undercooked characters, and an utter inability to stage a convincing love scene.

Since we know where "Revenge of the Sith" is headed--to Episode IV, the beginning of the original series--it can't hold too many narrative surprises. Is there anyone paying attention who'll be surprised by the revelation of the identity of master villain Darth Sidious? (Don't worry, I won't spill the beans.) But Lucas manages to turn the audience's familiarity to his advantage: like a jigsaw puzzle whose final form has always been known, the fun is in discovering how the last pieces fit. When that massive, menacing black Vader helmet clamps down on the deformed head of the boy we used to know as Anakin, the frisson has a mythic kick.

This is the most savage and despairing of the "Star Wars" movies. The surviving Jedi knights are forced into exile, and the Empire consolidates its evil power. This glimpse of intergalactic hell inspires moments of epic grandeur that haven't been felt since "The Empire Strikes Back." It's hard not to feel that Lucas's engagement with this story has a contemporary urgency, as line after pointed line invites us to see a parallel with today's wartime climate. As the Senate cedes power to Palpatine under the guise of intergalactic security, Natalie Portman's Princess Padme exclaims bitterly, "So this is how liberty dies--to thunderous applause."

Twenty-eight years after "Star Wars," the curtain finally falls. Lucas started by remixing myriad old Hollywood formulas into a hyperspace hybrid that felt new. Now, at the end, his own formula has inevitably become old-fashioned itself. For all the technological changes Lucas has embraced, his wide-eyed, childlike approach to storytelling--cute robots, scary villains, selfless heroics, fortune-cookie wisdom and wild roller-coaster rides through space--has remained the same. You can argue whether it's for better or worse. What you can't argue with is that he's stayed true to his vision, and that that vision has changed the cultural landscape irrevocably.