The "Lord of the Rings" trilogy is the greatest cinematic achievement of the past 30 years. It could earn that distinction on the merits of its technical and logistical feats alone (Three epic films shot back-to-back! Amazing computer-generated effects!); factoring in its grand themes, energetic storytelling and heroic characters only puts it that much further out of reach.

The final film, "The Return of the King," is probably the best film of the year and definitely the best adventure film since -- well, since "The Fellowship of the Ring" two years ago. The stories begun then, and ably continued in "The Two Towers," are concluded here with the same high-flying mix of drama, passion and adventure that has marked the series.

We begin with a harrowing flashback sequence showing Smeagol's gradual and gruesome transformation into Gollum, a reminder of the ring's terrible power. From there we continue the split storylines as begun previously. Frodo (Elijah Wood) and Sam (Sean Astin) continue their trek toward Mt. Doom to dispose of the ring in the fires of Mordor, with Gollum (Andy Serkis) as their guide, though his good intentions seem ever more doubtful. Gandalf (Ian McKellen), Merry (Dominic Monaghan) and Pippin (Billy Boyd) learn that Gondor, the last stronghold, is about to be attacked by all of Sauron's evil forces, but Denethor (John Noble), the man serving as steward in the absence of a king, has gone a bit dotty since the death of his son Boromir (Sean Bean) in the first film. Aragorn (Viggo Mortensen), Legolas (Orlando Bloom) and Gimli (John Rhys-Davies) recruit backup forces, even as Aragorn continues to pine for Arwen (Liv Tyler), who for some reason is dying.

The film is heavy-laden with plot, as always, and I confess some of it, like the Aragorn/Arwen thing, holds little interest for me. Viewing all three films consecutively, such minor subplots might feel more substantial than they do with a year's time between installments.

But the things that do work, work fantastically as ever. The bad guys are flying around on these fearsome, shrieking dragons now, and I shuddered each time one flew across the screen. Frodo and Sam face an enormous spider that is one of the most convincing special effects in recent memory, made all the more terrifying by director Peter Jackson's heralded sense of horror-film timing. (Just when you think it's safe....)

And then there's the battle of Gondor itself, so colossal it makes the battle for Helm's Deep look like a drive-by shooting. You wondered how they'd keep it from looking like a repeat of the Helm's Deep battle when it's almost the exact same situation? Here's how. Hundreds of thousands of participants, from orcs to men to elves to giant elephants to undead soldiers engage in combat, all of it meticulously rendered so that even the most impossible elements seem more real than computer-generated. Every bit of it is bigger, grander, more exciting, than before. The trilogy never feels more huge than it does in these sequences.

But Jackson's particular brilliance (shared by co-writers Fran Walsh and Philippa Boyens) continues to be his ability to deliver such magnificent visual thrills without forsaking the humanity of the work. I can think of many films (including some trilogies) that dazzle me with spectacle but never make me feel anything for the characters themselves. The "Lord of the Rings" set has managed both, and continues to do so here. When it all ends, and the many stories are wrapped up in a succession of final scenes, it's awesome to contemplate how much life has been infused in these action-oriented tales.

I am struck also by how "The Lord of the Rings" develops such beautiful themes of sacrifice, loyalty and friendship in the most harsh circumstances. Middle Earth is in ruins; the skies are so often black; all the world seems desolate; and yet here are these hobbits, elves, dwarfs and men laboring against impossible odds to restore peace and order. They don't have high-minded goals like "defeating evil," though obviously that is the byproduct. What they want to do is to make life enjoyable for themselves and for those they love. If that means defeating evil, well, then, so be it. As with most great films, we find universal themes couched in unique, imaginative settings. This is a trilogy to be treasured, and the final chapter is a fitting capstone.

Grade: A

Rated PG-13, a lot of battle violence

3 hrs., 20 min.