That thing you fu

The thing about American action movies is that they tend to be 90 percent tedious stuff like plot and snappy one-liners and only 10 percent fighting and things blowing up. Generally, story lines and dialogue are fine features for a movie, but when an action movie doesn't contain enough action, well, it's like a porno that doesn't have enough sex. Even in a high-voltage flick like "The Matrix," we had to wait forever for Keanu to emerge from warm goo and start leveling buildings.

That's not the sort of problem you're going to have at a Hong Kong movie. Case in point: "Black Mask." Within the first 10 minutes, rival crews obliterate an entire warehouse and nearly everyone in it with the kind of apocalyptic guns-and-grenades spray that domestic actioners save for climaxes. It's not subtle, but it does get your attention.

The threadbare excuse for all this carnage is the rebellion of a gang of genetically engineered humans who are extraordinarily strong and oblivious to pain. These mutants -- called 701s -- were designed to fight crime, but like all cinematic science experiments, something went horribly awry. Now they're aggressive mutants, waging spectacularly cruel war on both police and local drug lords in order to establish themselves as the city's main muscle. There's, of course, only one man who can stop them.

Michael (Jet Li) is a tamed 701 who also happens to be a mild-mannered librarian. (No kidding.) It's just a matter of time -- this being an HK film, about six minutes -- before his past catches up with him and he has to start busting 701 skull. But since he's so comfortable in his new, Dewey Decimal System lifestyle, Michael decides to do his destruction undercover, employing a snazzy mask and what looks like a chauffeur's cap. ("That Kato look is soooo retro," one female character sniffs.)

All of this is just filler, of course. The main reason anybody watches a Jet Li movie ("Once Upon a Time in China and America," "Lethal Weapon IV") is to see what Jet does best: kick butt and defy gravity. He tumbles, he crashes through windows, he fights while swinging from chains and balancing on slender beams. He may be the only actor who can box someone's ears with his feet, who can look menacingly cool brandishing cartons. For 90 minutes, this is pretty much what Jet Li does, and he does it like a relentless Rock-'em Sock-'em Robot.

It's not quite as entertaining to watch bombs explode and guns rat-a-tat in the wake of recent events in Colorado, even knowing that "Black Mask" was released overseas two years ago, long before Columbine. And the movie's new hip-hop soundtrack, with songs like "Killing Spree," may be an ingenious way to draw youngsters and rap fans to the theaters, but it also delivers an unintentionally ominous chill. To the movie's credit, very real-looking pain accompanies the violence: Li may bounce back, cyborglike, from his fights, but it doesn't diminish the big ouch he wears every time some leviathan flies feet-first into his chest. As he pirouettes on girders at the top of an unfinished building, his precariousness is both breathtaking and nauseating. The poetry of Jet's work isn't that he makes it look easy. It's that he makes it look absolutely grueling.

Imitations from the likes of Tarantino and Ritchie may come and go, and HK stars like Jackie Chan and Chow Yun Fat may cross over to stateside success. But there's still something about Hong Kong originals that's unlike anything else. Sure there's lousy dubbing, puzzling editing and implausible plots. But put Jet Li in a snazzy slicker and let his fists start flying and nobody -- not even Keanu -- can compare. Action-wise, his shoes are the ones to fill, and as long as they remain mid-air, eye-level and very, very fast, no other performer can some close.