A SICK, SOUR FEELING settled into the pit of my stomach early on in "Mean Creek" and, over the course of the film, just got worse (by which I mean better). Though it is clear from the start that something bad -- very bad -- is bound to happen here, and does, there is satisfaction in the film's defiantly unhappy anti-resolution that will appeal to the same quirky subset of people who appreciated the darkly depressing "River's Edge," "Kids" and "Bully."

We've all heard the saying that "[expletive] flows downstream." That, in a nutshell, is the real lesson of "Mean Creek," a drama whose plot concerns a tragic boat accident, but whose deeper subject is the world of casual teenage cruelty and its consequences. It's a world where an adolescent boy calls one of his friends, who happens to have two dads, a "faggot," simply because he turns down a puff of marijuana.

Call it "Mean Boys" and cut the comedy.

Filmed in grainy, documentary style, "Creek" doesn't take long to build an inexorable downstream momentum. When Sam (Rory Culkin) gets beaten up one too many times by the class thug, George (Josh Peck), Sam's older brother (Trevor Morgan) enlists the aid of a couple of his pals in a plot to humiliate George during a Saturday afternoon river-boating jaunt. Problem is, the kids end up actually liking George, at least enough to call off the plan.

George, however, is unable to utterly overcome his ingrained bullying nature, even though, up close, he reveals himself to be more of the sad, lonely loser than the sadistic villain. It doesn't help matters that George obviously idolizes Marty, another older boy who is the group's real bully, and with whom friction will ignite the film's awful climax. No surprises here -- Marty is himself a victim of his own older brother Kile's (Brandon Williams) bullying.

Part of "Mean Creek" involves the struggle to sort it out and do the right thing against enormous peer pressure. Its denouement, in fact, centers around the conflict between Marty's desire to cover up what happened on the boat and the need of the others to face up to their actions.

That the right choice ultimately gets made, albeit way too late to make a difference, hardly matters.

That's because "Mean Creek" isn't about doing the right thing, but doing the wrong thing. Never preachy, never sanctimonious nor touchy-feely, "Mean Creek" looks at what a social worker would likely call the roots and the legacy of abuse. I call it a film about the making of little monsters who will grow up to become big monsters. In the way first-time feature director Jacob Aaron Estes tells that cautionary tale, there is an attenuated, ghastly beauty.

MEAN CREEK (R, 87 minutes) -- Contains obscenity, violence, teen drinking, drug use and sexual content. At the Cineplex Odeon Dupont Circle and Landmark's Bethesda Row.

An outing turns tragic for Marty (Scott Mechlowicz, left) and Sam (Rory Culkin) in "Mean Creek."