The burden the men of Brokeback Mountain carry can be summarized with this terse exchange, which takes place the morning after a freezing night that forced them to share a tent: “You know I ain’t queer.” “Me neither.”

The big flaw—or perhaps it’s just a mainstreaming tactic—in Ang Lee’s basically enjoyable film is that before the first instance of frantic unbuckling, you’d believe those statements to be absolutely true. Indeed, even if you know the gist of E. Annie Proulx’s short story (here adapted by Lonesome Dove writer Larry McMurtry and longtime collaborator Diana Ossana), the clues that Ennis Del Mar (Heath Ledger) and Jack Twist (Jake Gyllenhaal) are interested in each other are verrry subtle. The way they fidget and exchange sideways glances when they’re first hired, maybe. Or Jack’s watching Ennis walk away in his truck’s rearview mirror. And then there’s the time at the guys’ mountaintop camp when Ennis undresses to bathe and Jack steadfastly keeps his eyes averted.

But these are cowboys we’re talking about, and some viewers may see the above as simply the way men of few words size each other up or avoid looking at another guy’s prairie. It’s at least clear that over the course of their sheep-herding summer of 1963, goofy Jack and reticent Ennis do develop a sort of friendship, which mostly involves complaining about their steady diet of beans and occasionally wrestling in the grass. When the job ends, the cowboys part ways with barely a nod, with Ennis, a ranch hand by trade, off to marry his fiancée, Alma (Michelle Williams), and settle down in Wyoming. Jack, a rodeo cowboy, returns to Texas, where he meets his future wife, feisty rodeo queen Lureen (Anne Hathaway).

Four years and two screaming new Del Mars later, Ennis receives a postcard from Jack asking to visit. When the men once again lay eyes on each other outside Ennis’ home, passion takes over—with Ennis foolishly embracing Jack within Alma’s view. She says nothing as the pair go off on a “fishing trip.” She says nothing when they return. This scenario repeats over the next 20 years, and another of Brokeback’s flaws is how quickly this period whizzes by, with Lee giving little indication of the years passing besides the number of kids around and the style of the wives’ hair.

And if you don’t buy the allegedly deep love that was set up in the opening scenes, the men’s decadeslong affair never seems as intense as it’s supposed to. At least not until the later years, when the warm-eyed, puppyish Jack begins suggesting—and then pleading—that he and Ennis set up household in the mountains and quit their loveless lives. Ennis, however, is against it—probably because when he was a kid, his father made him view the body of a gay-bashing victim.

Lee’s lackadaisical direction doesn’t sink the movie, however. The script is both heartbreaking and funny, often at the expense of Ennis. (When a supermarket clerk tells him that he can find his wife in the condiments aisle, he responds, “The whuut?”) And cinematographer Rodrigo Prieto makes Brokeback a beauty, especially in the opening scenes of strange mint-green hills and swirled pastel skies that look painted by Michelangelo. The landscape provides a metaphor, of course, with the openness of the country standing in sharp contrast to the restrictive suburbia that Ennis hides in. But it’s in his cramped trailer—filled with a couple who barely talk and the kids they can barely support—that the film finds its truest and most gut-wrenching emotion.

The biggest reason the Del Mars’ marriage seems the only genuine relationship in the film is because of Ledger’s and Williams’ career-making performances. Squinting under an ever-present hat and speaking with the low, wearied grumble of a man twice his age, Ledger’s Ennis is stoic and closed-off, offering only occasional hints of the head-on collision smashing in his guts. And Dawson’s Creek vet Williams is devastating as a wife who quietly carries the burden of the truth her husband won’t tell her. A love story in which you can’t feel the love might sound like a dismal failure, but in Brokeback Mountain’s case, it ain’t.