Knock Off is a strange film; it may seem off-putting at first because it's switchblade fast and a bit (okay, more than a bit) careless with the narrative. But it's only the second time filmmaker Tsui Hark has ever done an English-speaking film (much less a Hollywood production), and the first time_ever_that Van Damme has ever tried full-length comedy; a lot of ground is broken, so a lot of the footwork is understandably shaky.

The script (by Steven Souza, who wrote Die Hard) is complicated at first glance, but it boils down to this: someone is making nanobombs_powerful explosives equipped with a computer-chip fuse that detonates on a remote signal. The gimmick in this particular MacGuffin (Alfred Hitchock's term for the generic object of concern in any thriller) is that the bombs are infinitesimally small_so small they can be hidden inside the head of a doll, or put in the button of a pair of pants (Irrelevant note: this may be the first time nanotechnology [technology that makes use of microscopically small machines] was employed in an action film, though nanotechnology has been a hot topic for some time in cutting-edge science, and in cutting-edge science fiction).

Van Damme is a Hongkong businessman who has been inadvertently producing knock-offs_forgeries or fake versions_of brand-name jeans (the deadly little devices are sewn into these jeans). Hongkong is famous as a manufacturer of these knock-offs, but Van Damme, who was formerly known as "The King Of Knock-Offs" is furious; he sincerely wants to make legitimate products that are reasonably safe (meaning they don't explode at the touch of a button). He wants to find the maker of these bombs, but in Hongkong, who can say for certain who is responsible? One of the most interesting conceits of the film is that none of the characters are who they say they are; every one of them is a knock-off. His business partner (Rob Schneider) may or may not be a CIA agent; his best friend may or may not be a willing collaborator in the nanobomb scheme; a beautiful black woman may or may not be the corporate executive of a famous brand of jeans. Who can tell? In a city full of dazzling, deceptive images, truth is a rare and slippery commodity.

There is, however, no doubt as to the authenticity of the director. Of the three master filmmakers who have broken out of Hongkong to work in Hollywood_John Woo, Ringo Lam, and Tsui Hark_Hark is at first glance the shallowest. His films often have a cartoon quality; unlike Woo's or Lam's, Hark's characters are strictly lightweight. That's why Hark can take Jet Li (who can't act, but can kick), and mold him into the legendary Wong Fei-Hung of the Once Upon A Time In China series, while Lam and Woo need Chow Yun-Fat (who can act, and how) to flesh out films like City On Fire or The Killer.

But one still has expectations of Hark; for one thing, he has a range Woo and Lam do not. He can work in a whole range of genres, from action to horror to science fiction to romance, sometimes all in the same film; the odd combinations work more often than not, the result of nerve, speed, sheer energy and force of will.

As mentioned, he did the first three (and the three finest) installations of the Once Upon A Time In China series; created the horror classic A Chinese Ghost Story; parodied James Bond films in Aces Go Places 4: Our Man In Bond Street; and whipped up an exhilarating melange of martial arts, low farce, period filmmaking, and feminism in Peking Opera Blues.

Knock Off is a similar chop-suey, mixing nanotechnology, martial arts and comedy with spectacular stuntwork (on his last Hollywood project, Hark complained that American stuntmen refused to take the kind of risks Hongkong stuntmen take for granted). Hark doesn't even bother to worry if the mix will gel; he just goes at it willy-nilly, and the speed of his execution stuffs the spiky, imaginatively lumpy mess up your nose and into your brain before you can say "Ouch!" He does pause, though, to spark your mind with the occasional bit of visual flair: a set of knives falling_in slow motion_to the floor; Van Damme executing a particularly balletic kick (his martial arts seem to improve exponentially when he's handled by a Hongkong director); cargo containers tossed casually into the sky like so many matchsticks.

The humor in Knock Off is part of what makes the film so peculiar; it might help if you're familiar with humor in Hongkong movies, which isn't subtle but has a distinctive, imaginatively wild kind of energy. Some of the jokes don't work_the scene at the end where Van Damme monkeys around with the detonator is too labored and long. But the rickshaw race, with Van Damme running on a pair of disintegrating rubber shoes (knock-offs, of course), is a real gem, and his reaction upon realizing that a nanobomb was sewn into the crotch of his jeans is amusingly desperate (unlike Steven Seagal, Van Damme is apparently unafraid to look silly onscreen). It helps that Van Damme and Rob Schneider have an easygoing comic chemistry together; when they banter, they banter like real friends who've spent too much time in each others' company.

Knock Off doesn't have the outrageous imagery that was the glory of Van Damme and Hark's previous collaboration, Double Team, where a tiger stalked a minefield, exploding Coke machines flew through the air, and Dennis Rodman (always an outrageous image) played loving mommy to a bouncing baby boy. It doesn't have the beautiful simplicity of his Once Upon A Time In China movies, or the nuttily operatic intensity of his last Hongkong film, The Blade (One-armed man with a broken sword studies one-armed swordfighting from one-half of a damaged book. How much nuttier_or more operatic_can you get?). But it has a crazed integrity of its own, a brash confidence in things that shouldn't work somehow working out anyway. It's a standard Hollywood project that transcends standard Hollywoodness through sheer intensity of visuals and sheer oddness of humor.