Xxx

More wow-worthy than an afternoon at the X-Games, more feebly-scripted than a gunfire-filled X-Box action game rated "M" for mature, "XXX" is cool, cool, cool until director Rob Cohen gets to the last act and has to make room between stunts to resolve the knuckleheaded plot.

Billed as a tattooed, testosterone-injected, street-smart, 21st Century usurper to James Bond's explosions-and-espionage glory, the flick is a custom-designed career vehicle for Vin Diesel, Hollywood's fastest-rising bald-and-bulging bad-ass. Considered a hot property after stealing all the thunder in "The Fast and the Furious," Diesel has re-teamed with Cohen, that film's director, for this picture about an extreme sports daredevil and social activist hoodlum recruited by the National Security Agency to go undercover where their Bond-ish, well-bred, erudite agents can't fit in.

The movie begins with Xander Cage (Diesel) -- known as Triple X because of a tattoo on the back of his neck -- swiping the new Corvette of a politician who wants to censor rock music and video games. He straps cameras to the car, then gives a live web-cast diatribe about the First Amendment while driving off a bridge into a gorge and parachuting to safety as the car blows up.

Soon thereafter he's dart-gunned and kidnapped by black-ops NSA troops who repel through the windows of his hip-grungy, warehouse-conversion loft. He wakes up in what looks like a diner, where he foils a fake robbery then proceeds to tell the secret agent scout who has been watching him (Samuel L. Jackson, sleepwalking through a sardonic mentor role) how and why he knew the whole thing was a set-up. Another "test" follows, in which Xander and a couple other ruffian recruits are literally dropped into the middle of a Colombian drug operation to see if they'll survive. Soon Triple X is jumping a motorcycle over the roof of an exploding barn and between two strands of razor wire atop a 30-foot fence while military helicopters blanket the joint with machine gun fire.

Such scenes are a blast -- often literally -- even if they are scored with loudly monotonous angry white-trash rock (bands with names like Hatebreed litter the soundtrack). And the action only gets better. The film's most visually amazing showpiece involves Triple X deliberately setting off an avalanche then out-running it on a snowboard. By the time it occurs to you the wall of snow must be a special effect, your heart is already pounding.

But whenever the stunts stop and the story kicks in, "XXX" nose-dives into the land of lobotomized screenwriting (by "Airheads" scribe Rich Wilkes) and the movie's facade of adrenaline-cool falls to pieces.

Fully deputized as a one-time NSA operative, Triple X is assigned to infiltrate a gang of leather-clad, unshaven Euro-thugs from Central Casting who host raves every night and bed anonymous bimbos that wear little more than charcoal briquette eyeliner. (Women, including spy-girl love interest Asia Argento, are nothing but currency and sex toys in "XXX.")

By day these party animals are anarchist terrorists who have some vague, laughably far-fetched and entirely unmotivated plan to poison the world's water supplies using a remote-controlled submarine that fires biological weapons. As villains, these clowns have all the credibility of a professional wrestler without a nickname, and foiling their plan is absurdly easy since the picture's finale ignores all kinds of "facts" established earlier in the story. The aforementioned submarine, for example, launched from a mountaintop hide-away that suddenly has a river at its base when the script calls for it, never submerges. So Triple X can follow it and jump onboard from a bridge, saving the day in an unnecessarily complex way when blowing the thing up with a missile launched from his tricked-out 1967 Pontiac GTO would have sufficed.

Diesel almost saves "XXX" by cutting such an impressive figure as an action hero. Muscle-bound, menacing and pug-mugged but exuding sexy, cavalier confidence, he's a good enough actor to sell the secret agent potential behind his fearless, street-wise, live-for-the-moment character. If there's anything screenwriter Wilkes does right, it's not to saddle the guy with stupid catch-phrase dialogue. Triple X speaks more like an ironic post-catch-phrase hero. "I like anything fast enough to do something stupid in," he says of his beloved car. If this movie is a hit, Diesel and The Rock ("The Scorpion King") are set to become this decade's Schwartzenegger and Stallone.

Unfortunately, early thrills, groovy gadgets (X-ray binoculars!) and oozing style and personality don't change the fact that "XXX" becomes so monumentally idiotic and cliché-driven in its last 30 minutes that even checking your brain at the door won't be enough to insulate your intellect from its insultingly incompetent and self-contradictory conclusion.