What's the difference, in movie terms, between want see and must see? Answer: the second and third Matrix films. Before it opened in May, The Matrix Reloaded had fans drooling to find out how Larry and Andy Wachowski, the gifted brothers behind The Matrix, would expand the first movie's vistas and visions. That's want see in its most avid form. It earned Reloaded a record $209 million in its first 10 days but only $72 million in the rest of its run, a sure sign it disappointed its audience. So when the trilogy's finale, The Matrix Revolutions, arrived last week, seeing it was not so much a craving as a duty. Hence must see. As in must eat soybeans. Must visit Aunt Harriet. Must complete my set of Matrix in-theater viewing experiences.

Like Reloaded, Revolutions begins with no flashbacks, no summary of the story thus far. For those who are hazy on the battle of the reborn computer whiz Neo (Keanu Reeves) and his band of rebel humans against Agent Smith (Hugo Weaving) and the nasties of the virtual-reality Matrix, a brief refresher course is in order.

The 1999 original was a genuine Neo classic. It trumped its nifty martial artistry and digital effects with a theme of self-discovery in the great heroic tradition. So, what did the brothers do for an encore? They spread the sequel over two feature-length films and, with all that time to fill, got a little gassy in their storytelling. The rebel fortress of Zion was a drab lair whose denizens engaged in way too much Jedi Council — style nattering. Then — as if producer Joel Silver had pleaded, "Could you please have somebody hit somebody?"--Reloaded 180'd into an action film, with the most elaborate car chase ever shot but without the first film's zip or resonance.

Well, Silver did warn us: M2, he said back in April, was "only half a movie." Revolutions is the other half, and if it doesn't touch the original for sheer cinematic wow, it's a big improvement over M2 and brings the enterprise to a satisfying climax.

Neo is now unplugged, lost in a nightmare realm between the Matrix and the machine world. He's pursued by Smith, who has gone free-lance and has become a fatal computer virus. Neo's friends Morpheus (Laurence Fishburne) and Trinity (Carrie-Anne Moss) can't count on him, so they must plan the defense of Zion with the help of only the fractious rebel commanders. Their immediate obstacle: the pruny, petulant, dangerous Merovingian (Lambert Wilson). Their possible key to Neo's location: the Oracle (Mary Alice), who, we learned in M2, is a computer program and not always trustworthy.

The movie takes its time reaching warp speed. The Zion debates drone on, and much of the acting and dialogue is stilted, perfunctory, at a level somewhere between a Star Trek TV episode and a Star Trek convention. But the ass kicking starts early, when Morpheus and Trinity have a cool fight with the Merovingian's goons. Meanwhile, Neo is being dogged by a "human" whose voice sounds ... strangely ... familiar. Our hero's lids are seared shut, and through the hot coals of his X-ray eyes, he sees Smith, grimacing triumphantly. It's one of the epiphanies of the movie year.

Any martial trilogy needs a climactic battle scene. This one pits the humans against a swarm of the Matrix's sentinels — those metal octopests, those enemy anemones that chased the humans in M1 and M2. They're back in megaforce, forming a snake shape that rears and strikes at Zion. So the human soldiers get outfitted in gigantic robot armor — clinking, clanking, clattering collections of collagenous junk.

Ah, yes: The Wizard of Oz. That's the touchstone here, not just in the war of a few good guys against a vicious aerial host but in Neo's trip to the Machine (Emerald) City to meet its virtual vizier — who, as seen on a giant screen, looks a bit like the Oz wiz in the 1939 movie — and learn how to get home.

Somehow, though, you knew that the fate of the universe would hang on the outcome of a kung-fu fight between Neo and Smith. It comes at the end on and above city streets in a slow, heavy rain. The trilogy ascends and soars with the two combatants and ends not with a whimper but with a blast of light.

Thus the fabulous original film has found an honorable way to sign off. For those who didn't bother to join the early crowds, The Matrix Revolutions is a definite might see.