2 stars (out of 4)

"The Matrix Reloaded" thunders along not as a sequel but as an infinitely prolonged serial episode, complete with a "To Be Concluded" tagline followed, eons later, after the credits scroll, by a brief trailer for "The Matrix Revolutions," in which Keanu Reeves' Neo seems to be dancing in the rain.

The new, overstuffed compendium of kung fu, wire work, threads of myth and shards of philosophy, assembled by the Wachowski Brothers, Andy and Larry, adds up to much heavier lifting than "The Matrix," which itself suffered from fits of strained navel-gazing. But the Wachoskis' first venture into big-budget, F/X-laden movie-making spun out some memorable and much imitated action sequences, thanks to Hong Kong magician Wu-Ping Yuen. Who can forget the moment when Carrie-Ann Moss' black vinyl-sheathed Trinity suddenly raced along a wall like a gravity-defying Catwoman?

Moss is back in "Reloaded" and deeply enmeshed with Neo, also known as The One, or occasionally by his former name, Thomas A. Anderson, back in his life-in-death as a hacker nerd. Also on board is the coach and Zen master, Morpheus, again played with much gravitas by a burly Laurence Fishburne.The other major returning veteran is Hugo Weaving's Agent Smith, who has figured out a way to clone himself, thereby destroying his power as a sinister force of evil.

The Brothers Wachowski have worked overtime to surpass themselves, defying copycats, but they succeed only in making "Reloaded" almost completely unbelievable. The most trying sequence pits Neo against a virtual army of Agent Smiths in a flying, cartoonish fight sequence that proves more enervating than exciting. Fishburne's Morpheus also gets his chance to undo any interest in his character in an even longer battle atop a speeding trailer on an endless freeway.

The Wachowkis begin Book II dynamically, with Trinity's battle against Matt McColm's vicious Agent Thompson. Plunging from a skyscraper window, falling back-first, Moss's Trinity continues to crank off rounds. Then she is hit, and Neo awakens in a nightmare's sweat to find her safe beside him.

It gives nothing away to say that "Reloaded" employs a circularity as it unloads its saga of a threat to the underground Zion, a refuge from those infernal machines that have taken over the Earth and now are bent on destroying the free refugees. The Wachowskis' plotting is more unfathomable than ever, but amid their juggling with causality, fate and free will, two focal points emerge: Neo must save Trinity from her death in the bad dream, and he must head off the machines' killing monsters, giant octopussy things, burrowing ever deeper toward Zion.

But, of course, Agents Smith and Thompson, along with the countless clones and a pair of evil albino ghost twins, pop up at every turn to battle the forces of good. The Wachowskis have upped the African American quotient by casting Jada Pinkett Smith as Niobe, a captain once hooked up with Morpheus, and Harold Perrineau Jr. as Kain, a semi-comic pilot of Morpheus' ship. Zion is packed with people of color who indulge in wild raves, as Neo and Trinity make love in the wake of speeches from the leaders about the fate of the refuge. Gloria Foster, who died of diabetes after the film was completed, is back as the grandmotherly Oracle.

Neo's quest, which takes him through a bland corridor with many doors (of misperception?) that lead to places such as the Oracle's slum neighborhood, ultimately brings him to Merovingian, a condescending French overlord charged with European hauteur by Lambert Wilson. The consort of the effete aristocrat is one Persephone (in Greek myth, stolen to be queen of the underworld). As played by the ultra-curvy Italian bombshell Monica Bellucci, Persephone is a frustrated voluptuary who tempts Neo - as Trinity watches - into a prolonged kiss. This, in turn, leads to Randall Duk Kim's Keymaker, who has the means of opening many doors, and who becomes the film's sole endearing character.

But "Reloaded" does not really concern itself with people. It is about future noir style, long black coats, Philosophy 101, martial arts and flying. Yes, now Neo can really go up, up and away, like Superman. He also can render bullets even more ineffectual than in the first film and can even stop those mechanical octopi dead.

Reeves performs all of his miracles with a sober modesty and furrowed brow, listening intently to a harsh voice of reason as images of Neo and humanity hover about him on countless TV monitors. Though reminiscent of "Space Odyssey: 2001," if much more talky, this encounter, and its terrible choice, belatedly inserts a touch of mystery into a confused jumble of a movie, in which the machines have taken over the filmmakers.

"The Matrix Reloaded"
Written and directed by the Wachowski Brothers; photographed by Bill Pope; edited by Zach Staenberg; production designed by Owen Patersoncq; music by Don Davis; produced by Joel Silver. A Warner Bros. release; opens Wednesday. Running time: 2:18. MPAA rating: R (sci-fi violence, some sexuality).
Neo.....Keanu Reeves
Morpheus.....Laurence Fishburne
Trinity.....Carrie-Anne Moss
Agent Smith.....Hugo Weaving
Niobe.....Jada Pinkett Smith
The Oracle.....Gloria Foster