Set in a present-day London of cheap bars, seedy laundromats, government housing, and booze-blasted brain cells, Nil by Mouth plunges into this world with a fly-specked, pseudo-documentary style that's so immersive it starts out seeming incomprehensible. Opening in a sad music hall packed with bleary lumpens at play, the film consists of faces thrust into the lens and a strident cacophony of voices with cockney accents so thick, only half the words are intelligible -- and half of those are "fuck" and "cunt."

In the chaos, the truculent pig face of Raymond (an overwhelmingly convincing Ray Winstone, who looks like Aldo Ray on a bad day and could give Joe Pesci lessons in ecstatic fury) stands out. Buying drinks for wife Valerie (Kathy Burke, deserving winner of the Best Actress prize at Cannes), mother-in-law Janet (amazing first-time actress Laila Morse), and his pals (relationships that are never stated but must be discerned from the untidy evidence), Raymond gives a mere suggestion of the brutality and torment ready to erupt. With sly amusement and occasional asides, he listens to a demented friend tell hilarious, obscene stories about an orgy and a heart attack, laughing with everyone else at the skewed punch lines.

You could think of Nil by Mouth as a film about people who love stories because their own lives lack them -- outside the relatively civilized confines of the pub, their experience is confined to explosions of rage, violence, and need, with no beginning, middle, or end. Unfolding elliptically, the film cuts from scene to scene, some ending anticlimactically, others going ballistic without warning, evoking the shell-shocked response of one of the most peripheral but central characters, Valerie and Raymond's tiny, observing daughter. Like her, you're apt to cower into numbed, fascinated passivity, witnessing mutely.

Among the horrors are a scene in which Raymond bursts in on Valerie's waste-product brother Billy (Charlie Creed-Miles) to confront him with the theft of Raymond's "gear." Almost as frightening as Raymond's biting through the bridge of Billy's nose is the manic repetition of his accusations, which build in wrath to a final explosion that's a relief. Grotesque as Raymond is, the self-destructiveness of the other characters can be even more appalling. Tossed out on the street, Billy bums spare change, robs Raymond's flat, and hits on his mother for money for a fix. She waits in her car for him to return from his connection as if he were being picked up from school, and the look in her eyes as she watches him shoot up in the rear-view mirror -- anguish, revulsion, maternal compassion -- devastates.

It is Raymond and what eats him, though, that propel the last half of the movie. Driven by drink and contrived jealousy, Raymond beats Valerie in a scene whose barbarity eclipses anything in Once Were Warriors. She flees to her mother's, and Raymond's crescendo of madness collapses into pitiful impotence. In a rare moment of reflection he talks to a friend about his drunken, unloving father, and how as he lay dying in the hospital the attendants had put over his bed a notice reading "nil by mouth."

As explanation it's hardly illuminating (see "Film Culture," below). The performances are another matter. Soaking in a tub, Creed-Miles reminds us of the innocence wasted in Billy as he cheerfully does a monologue in a West Indian dialect. Burke's Valerie varies from sad-sack loser to loving spouse to steely, determined woman -- sometimes within one scene. And as much as one wants to see Winstone's Raymond laid out, the sight of him puking blood on the pavement before his family is one of the film's most poignant moments. Aptly titled, Nil by Mouth cannot put the tragedy of its characters into words; it makes you feel it.