Brokeback Mountain (15) <!-- none onestar twostar threestar fourstar fivestar -->

An elegy to lovesick cowboys

One of several remarkable things about Ang Lee's new movie Brokeback Mountain is that, though set in 1963, you could spend the first three-quarters of an hour imagining it to be 1863. The spareness of the composition, wherein a man, a horse and the yawning skies of Wyoming might be all that fills the screen, suggests a bygone age, and when one character expresses the hope that "the army don't get me", you have to correct your initial instinct: it's not the Civil War he's referring to but the Vietnam War. For a while, time seems to have stopped in this American pastoral.

Please do not miss a frame of these opening 45 or 50 minutes, because they are the most beautiful Lee has ever committed to film. Dreamlike and at the same time intensely realistic, they conjure an unlikely relationship - unlikely both for the time and place of its action, and unlikely for issuing from mainstream Hollywood. You may already know Brokeback Mountain as "that gay cowboy movie", but it hardly does justice to the nuance of texture and feeling that Lee has lovingly finessed. Adapted from the Annie Proulx short story, it begins with two young farmhands, Ennis Del Mar (Heath Ledger) and Jack Twist (Jake Gyllenhaal), riding out to tend sheep for a summer on Brokeback Mountain, a job that mostly involves chowing down baked beans and avoiding each other's eyeline. Ennis is the more reticent of the two, Jack the jokier, more open personality, and for long stretches the modest, plangent chords of Gustavo Santaolalla's guitar soundtrack fill the silences between them.

Nothing seems to happen, yet in the laconic phrases of the script (by Larry McMurtry and Diana Ossana) and in Lee's patient control of mood and landscape everything is happening, or about to happen. By degrees the intimacy that has united the two men lurches one night into physical passion, and, in spite of the awkwardness the morning after, a flame is lit between them. It is love, in fact, only a love that dare not speak its name, even to themselves. "You know, I ain't queer," Ennis mutters. "Me neither," replies Jack. That's the sum of their relationship chat. Too late they (and we) realise that their time together has been an idyll; once they come down from the mountain and pick up their old lives, reality sets in, and their nights of "stemming the rose", in their boss's resonant phrase, are seemingly at an end. Ennis gets hitched to his childhood sweetheart (Michelle Williams) and distractedly raises two daughters, while Jack goes back to the rodeo circuit - shades of Peckinpah's lovely elegy Junior Bonner here - and ropes himself into marriage with a feisty Texan heiress (Anne Hathaway).

Four years of drudgery intervene, but the spirit of Brokeback Mountain is reignited when Jack pays a visit to Ennis and the pair of them end up in a motel for the night. Can their relationship go the distance? The movie proceeds to cover two decades in searching for the answer, and in doing so transmutes into something anguished, fragmented and, it must be said, less satisfying. It's a problem that any movie leapfrogging the years will encounter; the time lapses jar (when did those toddlers turn into teenagers?) and the changes in appearance feel vaudevillian. Ledger and Gyllenhaal handle the transitions pretty well, dropping their voices and growing their sideburns, though neither of them can quite muffle their youthfulness. Williams offers a convincing portrait of a life worn down by misery and suspicion, but Hathaway's peroxide wig is so loud it seems to have taken on a role of its own.

After that symphonic opening, the desultory rhythm of the fleeting years causes the picture to sag, though it's kept alive by its central performances. I've always liked Gyllenhaal's easy-going slouchiness, and he makes Jack's idealistic hankering for a life with Ennis so passionate as to seem a kind of necessity. But the hidden weight of their tragedy is carried in the tight jaw and wary gruffness of Ledger's Ennis, who's seen enough of the world to know they are trapped, and probably doomed. As he tells Jack, "If you can't fix it, you gotta stand it."

Ledger and Gyllenhaal aren't the first mainstream movie stars to risk the box-office death of playing "gay" - River Phoenix and Keanu Reeves took a similar flyer 15 years ago as street hustlers in My Own Private Idaho - but they have made a start in the slow erosion of a stereotype. Jack and Ennis are not predatory, or mincing, or limp-wristed; instead of being the hero's best friend or the upstairs neighbour, they are fully realised human beings who (astonishing!) do macho stuff like ride steers and sleep on mountainsides. It will be interesting to see if anyone follows their lead.

As Lee's aria of regret nudges past the two-hour mark I thought it was out for the count, but it picks itself up and delivers a surprise double bodyshot whose concerted force will possibly floor you. It got me, first in the casual reunion of Ennis with his teenage daughter (played with tenderness by Kate Mara) and then in an achingly elegiac shot of, no kidding, an old checked shirt, the memory of which tugs a thread from an earlier part of the story. In fact, thinking about it right now, my throat seems to have constricted and my eyes gone all blurry. No, I'll be fine... Just give me a minute, will you?