Activists eager for Hollywood’s first drama centered on hydraulic fracturing may be disappointed by Gus Van Sant’s Promised Land, which is more a portrait of a small town under siege by corporate interests than an exposé of the controversial method of extracting natural gas. The film follows Steve Butler (Matt Damon) and Sue Thomason (Frances McDormand) as they attempt to buy subsurface mineral rights in the close-knit farming community of McKinley, Pennsylvania, which sits atop the gas-rich Marcellus Shale. The town is economically depressed, and presumably ripe to be saved by energy companies offering $5,000 an acre with 18 percent royalties.

Butler is good at his job: he grew up in a farming town that shriveled after Caterpiller pulled out, and he exudes blue-collar sympathy for the struggling farmers of McKinley. Natural gas is your only salvation, he tells them; it will raise your tax base and improve the quality of schools so that your children can escape to a better future.

Things appear to be going well for the landmen until a frail, elderly high-school teacher (played by Hal Holbrook) raises vague environmental objections to fracking at a town meeting. Unruffled and affable, Butler assures the crowd that government regulations will keep everyone safe. The teacher responds with the energy industry’s worst nightmare: he suggests that McKinley take a vote.

Butler and Thomason shake off the white-haired prophet’s warning only to be confounded by the arrival of an outside agitator: an earnest environmentalist named Dustin Noble (John Krasinski), who pitches his own farming narrative during an open-mic session at a local bar. After letting frackers onto my Nebraska farm, Noble tells the rapt crowd, seventeen cows died, and “the land just turned brown and died.”

What is the link between fracking and dead cows? No one asks, but the momentum has turned. (We know this because the patrons eagerly join Noble as he croaks out “Dancin’ in the Dark.”) The next day, Noble shows up at the local elementary school to explain fracking to a class. But this teachable moment, for moviegoers who might not know what unconventional gas extraction is all about, is blown when Noble dumps a random assortment of household chemicals onto a miniature farm and sets it on fire. Is this the best evidence he can muster against fracking? This laughably misleading demonstration is an insult to environmental educators everywhere. Still, it’s a hit with the schoolchildren and their teacher, whose affections Noble and Butler are soon competing for.

Promised Land is now a race against time. Will Noble win over more people -- including the teacher -- before the town votes on whether to allow fracking, or will Butler collect enough lease signatures? The story focuses on its charismatic antagonists, but it gives short shrift to the real-life frictions -- between family members, neighbors, and community members -- generated by the prospect of easy Marcellus money. The people of McKinley seem strangely detached from the matter at hand: why do so many of them reject fracking -- which could hold foreclosures at bay -- if they don’t understand its potential to harm the air, water, and soil? Is one photo of dead cows really enough to sway them? (Promised Land was filmed in two Pennsylvania counties with several hundred active gas wells, but it doesn’t show a single drilling pad or tanker truck.)

While frustratingly vague about characters’ motivations, Promised Land challenges viewers’ expectations and stereotypes, and its plot takes some surprising twists. The movie is most successful at conveying the lengths to which a corporation will go to subvert democracy and win community approval. In their newly purchased flannel shirts, Butler and Thomason bribe a local politician with $30,000; pay an environmental activist to disappear; ingratiate themselves by playing drinking games at the bar; and even throw a country fair, complete with petting zoo, Ferris wheel, and new uniforms for the baseball team. (There’s more to the company’s depravity, but revealing it here would spoil the fun.)

Ultimately, Promised Land is more about relationships and trust than the consequences of shooting millions of gallons of chemically laced water deep into the earth’s crust. Fractivists will have to be satisfied that moviegoers will depart the cinema knowing the oil and gas industry has something to hide -- even if they’re not sure exactly what it is.