Morvern Callar (15)

In Britain we don't normally have much time for auteur film-makers. We like professional, self-effacing all-rounders who can turn their hand to a good stiff challenge, play the game and all that. A little individualism is fine, but a film-maker whose identity and fervour are visible in every shot, that just smacks too much of the Continent. This shouldn't make any difference to the brilliant young Scottish director Lynne Ramsay, as long as she continues to get funding: I can't imagine she's any more bothered with the mainstream than it is with her. She won't be directing Richard Curtis scripts in a hurry.

British exhibitors didn't quite know what to do with Ramsay's first feature Ratcatcher, a story of Glasgow tenement living in the Seventies, and a savage, poetic refutation of Billy Elliot-style childhood nostalgia. So it'll be interesting to see how Morvern Callar will fare. This is an incredibly bold follow-up – in no way the expected second-feature exercise in "maturing" or simply upsizing, but a quite uncompromising sidestep into somewhere unmapped, just beyond the known regions of left-field. Very much an art film, and a European one at that (the closest comparison to Ramsay's not-quite-linear imagination might be France's Claire Denis), Morvern Callar is so tuned to its own thought-rhythms that it comes across as being nearly as aphasic as its otherworldly heroine.

Co-written by Ramsay and Liana Dognini, Morvern Callar is based on the 1995 novel by Alan Warner, arguably the first book to give the rave generation its literary papers of citizenship. Its young heroine (played by Samantha Morton) works in a supermarket in a Scottish port; in the depths of winter, she discovers her boyfriend has killed himself, leaving her his money and a completed novel on his computer. Morvern seems to go into shock, telling no-one about his death, but simply disposes of the body, sends the novel to a publisher under her own name and takes her best friend Lanna (played by Kathleen McDermott, a raucously sexy Glaswegian first-timer) off for a lark in Spain.

None of her actions are easily explicable – you can't quite pin down whether she's numbed, crazy, on a revenge trip or performing some wayward act of mourning. Losing the book's first-person narrative, Ramsay obliges you to find your way into Morvern's unearthly head by other means. Another film-maker might have strained to make Morvern reassuringly comprehensible, giving her spree an unequivocally sobering moral, or making the story one of those cynically hip Getting It Away With It larks that British cinema is forever grinding out. Ramsay does something else: she doesn't exactly put us in Morvern's head, but into her skin.

This is a remarkably tactile, sensuous film, full of the ache of cold and fatigue, the discomfort of stepping over a dead body to heat a pizza, the buzz of arriving in Spain where it's blazing hot and everything looks harsh-grained through a febrile yellow filter. The film's first part gives you the crawling melancholy of midwinter in a dank flat, Christmas lights blinking feebly. Its characters are like cave dwellers, huddling to the warmth of fires, beers, a headful of pills. The shot of Morvern floating in a pale bath, staring ceilingwards in dead silence, induces goose-pimples in more ways than one: Ramsay's imagery simply works into your bones.

Wherever she is, Morvern seems as though she should be somewhere else. Morton uses an English accent rather than the expected Scottish. "I'm not from here," she tells an unknown someone on the other end of a phone on a deserted railway platform at night. The actress's feral, haunted otherness – her face as sallow and wraithlike as if she'd dropped from the moon – is at once entirely engaging and inscrutable. Everything she experiences is less in her head than on the whole surface of her body: Morvern is an existential orphan of the storm, all nerves bared to the world.

The film's strangely ambivalent relation to a recognisable contemporary world can be seen in Morvern's visit to a package resort crammed with British kids all avidly frying their psyches. This sequence is euphoric, yet completely out of key with the usual depictions of youth-culture hedonism. The shots of Morvern framed against a wall of hotel balconies reveals the merciless factory-farmed fun ethic of such places: another memorable, fleeting shot reveals a girl's agony at being roped into a brutally jolly poolside romp. A sexual encounter unspools like a dream to the throb of a Lee Perry dub track, then suddenly passes: one of many moments in this sublimely discontinuous film where you wonder whether you imagined an episode, or nodded off and missed a vital connection.

Alwin Kuchler's richly textured photography keeps us at once in the mundane world and within Morvern's own hazy optic. But what makes Morvern Callar really special is that this is one of those rare films made for the ears as with the eyes: quite seriously, go and see it twice, once with your eyes shut. Ramsay and sound designer Paul Davies take a motif of the book, the compilation tape made by Morvern's boyfriend, and let it colour their soundscape, often to surreal effect: who'd have thought ravers' bars on the Costa del Sol would play mock-disco by German dub-dadaist Holger Czukay? It's not just the music, though, but all the film's sound that is sculpted, from the faint buzz of Christmas tree lights to the techno crash of a dancefloor sequence.

When the same sequence, with a glassy-eyed Morton swaying under the strobes, is cut at the end of the film to different music, the Mamas and the Papas' "Dedicated to the One I love", the effect is painfully poignant, although it's hard to tell why – either because Morvern is reconciled with her dead boyfriend and the world, or because she's spun off so far into her own lonesome stratosphere that there's no going back. Ramsay herself is certainly off on an orbit of her own, and it's just a shame that she has to carry the burden of being flag-bearer for new British film-making. The truth is, there aren't many film-makers here, or anywhere for that matter, making films of this intensity. Morvern Callar's wintry lucidity and fiery imagination will get into your head in the uncanniest way.

j.romney@independent.co.uk