Downstairs, the re-named Fringe and Firkin pub has all the hallmarks of a recent renovation: big TV screen, jokey slogans on the wall, miles of bar space. Upstairs at the Bush Theatre, the main surprise is that after pounds 1.2m spent on refurbishment the 100-seat venue looks exactly as it did before. There's still a small room with an awful lot of overhead lights; still nowhere to put a coat or bag; still someone's knee sticking into your back; and still a stage little bigger than a snooker table offering something as interesting as what's on anywhere else.

If you divide plays into those that seem, at first, to be exciting and then turn out to be boring, and those that seem boring but turn out to be exciting, then All of You Mine, the fourth play by Richard Cameron that the Bush has premiered, and the fourth to be directed by Simon Usher and designed by Anthony Lamble, is one that opens with remarkably little razzmatazz.

As you enter the venue, you cross Lamble's painstakingly recreated set of a backyard in a South Yorkshire village. It could be an installation in a Museum of Contemporary Life. Every detail, from the washing-up liquid on the window-sill to the dry tufts of grass by the concrete path, looks as if it has travelled several hundred miles down the M1. All of You Mine is set in the summer of 1996. The only moisture on the parched earth is where a member of the audience has spilt beer.

Cameron turns up the heat, slowly and inexorably, on one family in this ex-mining community. We see the Cades at close quarters. At this venue, where actors sit closer to the audience than they do to one another, the cast benefit more from their experience working in TV than theatre. They sustain an exceptional, unflurried level of naturalism, as reassuring and dependable as the tin of Family Circle biscuits they eat.

There are no grand theatrical gestures. Cameron's narrative method teases us with hints of big events, then drip-feeds us the key details. Twelve years ago, during the miners' strike, five men died in a pit accident. Flashbacks help us along, but the intricacies of what happened are tricky to follow. Briefly, what was always regarded as an accident was a piece of sabotage. One of the men killed was the husband of one of the sisters, Verna. This year, a memorial is about to be unveiled.

That event brings Verna, played by Marion Bailey with a lovely combination of toughness and grief, back home to fix her relatives with hard, questioning stares. In the words of her nervous, credulous brother-in-law, Earl (Andrew Dunn), she's a "shit-stirrer". Cameron introduces us to the rest of the Cade family with the same archival care the designer takes over the lean- to porch.

Cissy (an impressive Anne Carroll), the blind, widowed matriarch, sits in her battered armchair, surrounded by wilting pot plants that she can't see. One of her daughters, Alma (Melanie Kilburn), works at the garden centre that has replaced the old pit, a punctured look of disappointment spreading across her face as she discovers more than she would like to know about her husband. Her prosperous brother Danum (David Hounslow), squinting in the bright sunlight, which bounces off the gold buckles on his shoes, shifts subtly between authoritativeness and unease. Alma's son Neville, a good-natured school- leaver (Lee Oakes, making an endearing stage debut), and the family friend Billy (Roy North), a picture of stoicism with a dog-lead hanging round his neck, complete this introverted world, which director Simon Usher rightly treats with the seriousness of a forensic scientist.

When the family returns to the backyard for a cup of tea after the memorial ceremony, this slow-burning play reaches its convincing and charged denouement. Unlike the noisier young playwrights, Cameron doesn't seek to impress us through calculated audacity, pastiche or glib violence. He achieves something else. He establishes a tone - careful, humane, and diverse - that pulses with quieter, stronger values. It's a voice we can trust.

The Shift is a mixed-media event, "created by the company", written by Clare Bayley (the Independent's former theatre editor) and developed through "workshops". It follows three generations of women, interweaving their destinies with that of Shakespeare's Ophelia, whom Tilly, the grandmother (Anna Niland), played professionally in 1947 and Izzy, the granddaughter (Laura Macaulay), plays at school in 1997.

The crunch question about mixed-media events that employ slides, videos, camcorders, etc, is: what exactly do these additions add? Too often they confuse detail with insight. To see slides of a map of Paris does little to set the scene for a Parisian cafe. Whereas, when Celia (Helen Lymbery) writes a letter, and we hear her speak her thoughts out loud, while we see (on an overhead projection) how few of those thoughts are actually making it on to the page, the mixing of the media produces a neat dramatic point. Elsewhere, the wide-ranging thematic ambitions mean that, in spite of some attractive comedic touches, The Shift spreads itself thinly: the scenes of student life in Paris in 1968 are as wearily familiar as the slide projections of Millais's Ophelia. I'd prefer to see a new play by Bayley, who has an ear for the quirkier side of female experience. Andy Lavender's diffuse staging ensures that, in the cavernous Young Vic studio, this event was mixed most in terms of its quality.

An entertaining one-woman show, at the Arts Theatre, titled Showstopper, presents scenes based on the life of Marni Nixon, the voice on the soundtrack for Natalie Wood in West Side Story, Deborah Kerr in The King and I and Audrey Hepburn in My Fair Lady. Dan Rebellato's witty script revels in the ironies of a woman who is in thrall to the people she helped. The talented Jackie Clune excels as the singer; though with an outstretched hand spread against her chest, fluttering eyelashes, and double-edged compliments, her character looks as if it might be just as effectively inhabited by a female impersonator.

Theatre details: Going Out, page 14.