THEATRE : Patrick Marber wins hands down

If ever a play lived up to a quote that was included in the programme, it is the National Theatre's production of Patrick Marber's new play, Closer. The paragraph is from Monogamy by the psychotherapist Adam Phillips, and the opening sentence runs: "Infidelity is as much about the drama of truth-telling as it is about the drama of sexuality." I'm not sure Marber fully knows what his new play is about, and he wouldn't be as good a dramatist as he is (and, right now, it looks as if he is the best of his generation) if he did. For Closer touches on a lot that is uncomfortably raw. But in scene after scene, the drama of truth-telling - to use Phillips's phrase - is the building-block.

In Closer, we meet four people living in London - journalist, stripper, photographer and doctor - none of whom know each other when the play begins. It isn't the lead-up to their sexual relations that intrigues us. Nor the sex itself. Nor the cyclical stages by which the four meet, sleep together, part, meet again, sleep together again and part again. The nerviness that powers Closer, and makes it the best new play since Art, lies in the questions and answers, denials and confessions that these actions precipitate. Here are people - three of whom make a living through the detached observation of others, one of whom does pretty much the opposite - who just can't stop themselves from wanting to know that little bit more. When the text of Closer is published, it may well contain one of the highest number of question marks in an English play.

As the journalist Dan, Clive Owen first encounters the taut, waif-like Alice - played with a riveting mix of toughness and vulnerability by Liza Walker - when she gets knocked down by a taxi and he takes her to the hospital. He tells her he works in obituaries ("the Siberia of journalism"). She tells him she is a stripper. A year later they are living together and he has cannibalised her life for his first book. When he does publicity shots for the book he meets Anna, the photographer (Sally Dexter). If Walker is the girl in his life, Dexter is the woman.

Marber's first play, Dealer's Choice, took place over one night of a poker game. The intricately plotted deceits and revelations in Closer span four years, use deft time-shifts, split the stage for concurrent confessional scenes and intercut events that occur at the same venue. The funniest scene is a pure lie. It is conducted in silence between Dan and Larry, the doctor (Ciaran Hinds), who do not know each other and are communicating on the Internet. Larry thinks Dan is a woman: "a nymph of the net". Sitting at his desk, with a fag in his mouth, Owen, a model of ironic insouciance, feeds the other's fantasies.

"All the language is old," Owen complains, when declaring his own love to Dexter. "There are no new words." Marber's stark dialogue doesn't disprove the point. In the wrong hands, this could be pain- fully brittle. But this superb cast, directed by the author, bring an awesome emotional punch to their deep, if narrow, preoccupations.

"If women saw one minute of our home movies," speculates Larry, played with a hulking bruised integrity by Hinds, "the shit that slops through our minds every day ... " Over the play's 12 scenes, we glimpse a fair quantity of slop. The bluntness with which Marber dissects emotions is mediated only by sheer technical poise.

The exclusively urban scenes in Closer move us from waiting room, studio, restaurant, gallery, club and characters' flats to the Zoo, London Museum and, finally, Postman's Park, where the artist GF Watts created a memorial to unknown people who died in acts of heroism. Here, news of a death brings the story full circle. Owen is now obituaries editor with no space to record anything but the death of a Treasury man. And, by this time, Marber's play has made euphemism and traditional sentiment very suspect. Dan left someone who needed him for someone who didn't. And for that reason. Alice maintained that deceit made her feel alive. And Larry offered her pounds 500 in a strip club just to tell him her real name: "Talk to me," he says. "I am," she says. "Talk to me in real life." In Marber's fierce play the desire for truth and intimacy appears to be as strong and reckless as the desire for sex.

The Birmingham Rep and the Market Theatre Johannesburg have joined forces to present Janet Suzman's new version of The Cherry Orchard, based on a South African adaptation by Roger Martin. Yes, there are cherries in South Africa: if you set the play - as Suzman and Martin have done - in the eastern Free State. This is Chekhov for the Nineties. If you're OK, you're "sorted". If someone annoys you, tell them to get "off your case". If you're uptight, calm down with Beta-blockers. If you're talking about money, break into a refrain from Abba. If you hang around the house in a completely useless way, excuse yourself as a child of the Sixties. If you need to chop down a tree - as indeed you will have to - use an electric saw.

You can relocate plays in either time or place, but the distinction immediately blurs as every place has its own past. Suzman's fascinating production is well acted: notably by Estelle Kohler as the estate owner returning from Paris, Jack Klaff as her hopeless dreamy brother and Burt Caesar as the black businessman who buys the orchard. So half the time this Cherry Orchard works as a play in its own right, and during the other half the tension between the original and the new version is illuminating. Yes, there are strong parallels between the seismic shift in power that followed the emancipation of the serfs and the dismantling of apartheid. Traditionally Russian gentry get an easier time on the stage than white South Africans. So the roles in The Cherry Orchard are reversed. In Suzman's version we are more aware of those who have been dispossessed for centuries reclaiming the land of their ancestors than we are of the Ranevskaya (here, Rademeyer) family losing their home. The production runs into problems as it confronts the issue of race. This is too big a theme to be side-stepped, but the more they refer to it ("Money don't equal white anymore"), the more we realise what we are missing: it's as if we're watching one play knowing another has been shunted into the wings. If Chekhov had been a South African writing in the 1990s, he wouldn't have written The Cherry Orchard.

There is a strenuously good-natured production of A Midsummer Night's Dream at the Open Air Theatre, which seems to rely on the sun setting over Regent's Park to provide whatever shadows the evening might have to offer. When Adam Sims, as a deadpan Flute complains he doesn't want to play the female role of Thisbe in the mechanicals' performance at the court, he takes the objection that he has a beard coming, and turns it into two statements. "I have a beard," he says, then sees the disbelieving Peter Quince (John Griffiths) looking at his smooth face, panics and adds: "Coming."

This is typical of Rachel Kavanaugh's inventive production, which looks as if it has run from lines 1.i.1. to 5.i.428 with the text in one hand and a joke-book in the other. When Sims reaches his death scene as Thisbe the sword is nowhere near him. So Ian Talbot, who as Bottom catches nicely the vanity of the keen amateur actor, and who is playing the dead Pyramus at this moment, rolls across the stage, snatches the sword and then rolls back again. If this isn't enough icing on the cake, Sims stabs himself three times with the knife and - oops! - he's using the handle instead of the blade.

As Puck, the exotic John Padden gives an almost balletic performance, which constantly suggests that he's about to do something alarmingly double-jointed. While as Helena, Issy van Randwyck (one of the Fascinating Aida team) becomes an Athenian soubrette: scrunching up her face and tottering around on pink lace-up boots. She even allows one strap of her camisole to keep slipping off her shoulder. Even more cuddly, Bottom has an ass's head that could be sold in a toy shop, complete with blinking eyes and twitching ears. This is a traditional Dream from the New Shakespeare Company that slightly belies the company's name. I only hope they do as much business at the box office as they do on stage.

'Closer': Cottesloe, SE1 (0171 928 2252), to 23 Aug. 'The Cherry Orchard': Birmingham Rep (0121 236 4455), to 14 Jun. 'A Midsummer Night's Dream': Open Air, NW1 (0171 486 2431), to 7 Sept.