"Fast Food Nation" was inspired by a 2001 non-fiction bestseller by Eric Schlosser called "Fast Food Nation: The Dark Side of the All-American Meal," a fact which isn't surprising. Creating a film narrative with interwoven characters and story arcs based on source material that has none of these things can't be an easy task, and writer-director Richard Linklater (2006's "A Scanner Darkly") and co-writer Schlosser prove it. For a motion picture setting out to dig its claws into the grim underbelly of the U.S. meat industry and American culture in general, "Fast Food Nation" is decidedly spineless and not exactly all that eye-opening. As an ensemble drama, it is just as uneven; major characters float in and out of the story, sometimes never to be seen again, and plot turns are dropped or forgotten about as soon as they're mentioned.

When it is brought to his attention that traces of fecal matter have been found in the burgers at fast food chain Mickey's, concerned company marketing executive Don Henderson (Greg Kinnear) travels to the burgeoning town of Cody, Colorado, to investigate the goings-on in the meat-packing plant. Taking a tour of the headquarters, he sees a spotless outward veneer of shiny modern technology and stainless steel. Researching further, however, Don learns that not all is as it seems—cow droppings are mixed in with the meat due to flawed machines going too fast for the human workers—and there isn't much he can do about it.

Meanwhile, illegal Mexican immigrants Sylvia (Catalina Sandino Moreno), boyfriend Raul (Wilmer Valderrama), and wayward sister Coco (Ana Claudia Talancon) no sooner have hopped off the truck in Cody that they are being employed by male chauvinist scuzball Mike (Bobby Canavale) in the meat-packing plant. Sylvia quickly resorts to taking a pay cut in exchange for a job as a hotel maid, but escaping the chokehold of the factory for good isn't as easy as expected.

Across town, responsible teenager Amber (Ashley Johnson) is a star cashier working at Mickey's who begins to raise her sights and look beneath the surface of what a fast food chain symbolizes after meeting a group of peaceful activists (Avril Lavigne and Lou Taylor Pucci, among them). Other characters making brief appearances include coldly blunt cattle supplier Harry Rydell (Bruce Willis), who tells Don in no uncertain terms that the meat-packing plants aren't perfect and never will be, so he might as well get over it; Amber's uncle Pete (Ethan Hawke) and mother Cindy (Patricia Arquette), who share differing views on the state of commercialism within the country; and Rudy (Kris Kristofferson), a lifelong rancher whose treasured land has begun to be taken over by housing developments. And so it goes...

"Fast Food Nation" lacks aim, an angle, and human drama—three necessities in a motion picture that hinges heavily on its political and social statements about the world we live in. Director Richard Linklater, usually so reliable when it comes to these things, either got scissor-happy in the editing room or never bothered to think out the roles of his characters and their place within the greater whole. There is an astute theme running throughout involving the shift toward technology over human interaction, and the increasing roboticism with which people treat each other in a corporate society—in one scene, Don's confessed unhappiness with his hotel stay is completely ignored by a chirpy front desk clerk who might as well be a pod person. The specific dealings with the multiple facets of the fast food culture—the packers, the sellers, the creators—are on less solid footing. Simply put, the movie unearths no new truths or original ideas on the subject, and save for a graphic depiction of cattle slaughter, almost appears to be holding back from the scathing attack intended.

For the first hour, Don Henderson's investigation into the fecal discovery monopolizes much of the screen time. Finding himself stuck in the same spot he started at, he leaves Cody for his own home and is never heard from again. The sudden disappearance of Greg Kinnear (2006's "Little Miss Sunshine") is jarring and messy; like all but one of the subplots, there is no payoff to the time spent with him. Showing enormous screen presence and naturalism is Ashley Johnson (2000's "What Women Want"), whose Amber changes her outlook on the fast food industry and the treatment of cattle through a chance encounter that isn't quite plausible. As with Kinnear's, her personal story doesn't reach a conclusion so much as it peters out and dies.

The most effective subplot and the only one to find a satisfying arc stars the powerful Catalina Sandino Moreno (2004's "Maria Full of Grace") as Mexican immigrant Sylvia, whose experiences once in America are paved with more hardships and sacrifices than she can imagine. As Sylvia comes to terms with a betrayal happening behind her back, she has no choice but to compromise her morals in hopes of making ends meet. Moreno never steps wrong in an emotionally naked performance. Also of note is a stunning Bruce Willis (2006's "16 Blocks"), whose charged and calculating one-scene turn as cattle supplier Harry Rydell is the best he's been in years. If only his lead roles were filled with such fire and passion, Willis would surely be onto something.

2004's documentary "Super Size Me," a stomach-churningly compelling look at the fast food business, held more persuasion and provocation in any ten-minute segment than "Fast Food Nation" has in 114 minutes. Director Richard Linklater has made a well-meaning picture that holds one's interest through the quickly revolving storylines, but he hasn't made a convincing or satisfying one. With a narrative too loose and prone to wandering—full sequences lead nowhere, as when two teenage Mickey's employees start to plan a store robbery that is never mentioned thereafter—"Fast Food Nation" would have benefited from narrowing its sights and zeroing in on what makes the people inhabiting the town of Cody tick. The ending, a sensationalistic look at a cow's death and subsequent butchering, is sobering but cheaply manipulative; if a meat-eater doesn't already realize the source of what they're putting in their mouth, they're seriously delusional. More memorable is the last image of a tearful Sylvia, placed helplessly in a position she is horrified of, and with no one to turn to or help her. Her story is one worth telling in "Fast Food Nation"—all the stories are, in fact—but they fail to cohesively come together amidst a crumbling foundation of partially thought-out ideas and halfhearted moralizing.