By now you know that Gummo was filmed in Nashville, is virtually plotless, and takes place in a mythical town that was once leveled by twisters. In the movie's impoverished Xenia, Ohio, adults are largely absent, sex is either a living or a perversion, and kids make money poaching cats for meat. This is the norm. The movie is largely a series of scripted and improvised outrages, enacted by a cast that mixes professional actors with friends and locals who were found by happenstance.

It's the blurring of the line between fiction and documentary that makes Gummo conceptually fascinating and dramatically frustrating. Fascinating, because with the movie's untrained performers, we're always aware that the set-up situations could explode into real mayhem. Frustrating, because at a certain point bad improvisation reveals nothing more than the performers' desperation and the director's lack of ideas. Scenes of two kids enacting a murder ritual in a junkyard or two skinhead brothers walloping each other recall the worst of John Cassavetes--the endless takes of actors bullying extras or repeating each other's lines while they stall for inspiration.

Only with Cassavetes, we never felt the director was looking down on his subjects. Documentarians such as Frederick Wiseman and the Maysles brothers were sometimes accused of exploiting subjects who couldn't or wouldn't think for themselves, but Wiseman and the Maysles could claim they were simply reporting. As manipulator of his fictional universe, Harmony Korine comes on like King Midas crossed with Spalding Gray: Everything he touches turns to performance art. He doesn't see anything wrong with using breast cancer or incest or mental retardation just to spice up his act.

The most discomforting aspect of Gummo is the sense that Korine used destitute people in Nashville so he could stick them with attitudes and actions he wouldn't dare otherwise. Korine may give himself a drunken, sentimental baggy-pants turn on camera, but when he wants somebody to declare, "I hate niggers," or to rant about gays, those words are carefully placed in the mouths of non-actors, who take all the heat.

As craven as Korine is in many ways, though, he's fearless in others. Even if Gummo is numbing and soggy, it's the first American movie this year to suggest a way out of the present dead-end of conventional narrative cinema. Movies don't have to tell stories in straight lines, and when Gummo works, it forces us to respond to the images onscreen without the crutch of narrative bearings or routine musical cues. The opening, in which a half-naked boy (Nashville skateboarder Jacob Sewell) shivers on an interstate overpass, is a great short film in itself; so is a beautiful scene of the boy and two sisters frolicking in a swimming pool during a rainstorm.