It's an exit that isn't in the text. But it's entirely characteristic of Nunn's gift as a director that he fills this familiar trial scene with details that strike us as completely fresh and appropriate. He has a 19th- century novelist's grasp of the multiple narrative strands that are available to him on stage.
Tubal's exit is one of dozens of moments that offer us new perspectives and alignments. Sometimes traditional readings are entirely reversed and new complexities are introduced. Unusually, Derbhle Crotty's fascinating Portia is attracted by the dash and swagger of Chu Omambala's Prince of Morocco and trembles as he approaches the caskets. When we reach the awkward moment where Portia dismisses the Prince of Morocco with the line that she hopes none of his colour will win her hand, Crotty is fighting back the tears. She makes the remark to pretend to her staff that she doesn't care.
Nunn has set his Merchant of Venice in the 1920s or 1930s. At first, as we hang out in a raffish nightclub with champagne bottles, tinkly music and cabaret girls in feather boas, we might be closer to Isherwood's Berlin than Shakespeare's Venice. But the lightly sketched setting fades in the presence of the perfor-mances, and there is never any attempt to push exact historical parallels. Henry Goodman's superb Shylock, although clearly a 20th-century figure, roots himself so deeply in his religious traditions that he defies specific dates.
He enters in black hat and overcoat, silver-topped cane and briefcase. A bright-eyed, bearded businessman in his fifties, Goodman has warmth and humour, which shifts, quickly and plausibly, to other extremes. He's utterly convincing: funny, frightening and heart-rending. You know that however many aspects of this character you witness you will never catch a glimpse of the actor himself.
When Goodman hits on the idea of a pound of flesh serving as a bond, he laughs and laughs, before actually voicing it, as if it's a piece of mischief that he simply can't resist. When he lectures his daughter about shutting the windows during the carnival, we see a widower and single parent losing control and slapping his teenage daughter. After Jessica has run away, Goodman returns to their home, knocks, finds no answer, pushes the door open and goes in. It's another powerful exit that isn't in the text.
Nunn presents the changes of fortune in the trial with a verve that catches every drop of tension. His control of focus, when switching between the two ends of the Cottesloe's traverse stage, is absolute. Goodman's Shylock has to battle with the court. He also has to battle with himself. He nearly wins over the former and loses the latter. Crotty's Portia only thinks of the legal loophole as Goodman brings his knife to Antonio's chest for a second attempt. When the court forces him to convert to Christianity he removes his yarmulka and tucks it on to the scales that he had brought to weigh Antonio's flesh.
It's exemplary. Nunn and his National Theatre Ensemble are currently presenting the two best Shakespeare productions in the country. All he needs to do now is bring in some other directors who can meet his own standards.
Declan Donnellan's inflammatory revival of Noel Coward's Hay Fever will send many traditionalists scurrying for their antihistamine. It's a nightmarish take on the play, as if we were witnessing the entire sequence of events at 2am through a lurid alcoholic haze. Coward's 1920s comedy unfolds over a weekend at a country house in Cookham where the smart bohemian hosts are - as Coward would put it - perfectly horrid to the guests. Donnellan turns this upside down.
He tacks on a new opening, where we see an actual performance of "Love's Whirlwind", the melodrama quoted later in the play, that's been a personal success for the actress mother, Judith Bliss. Donnellan then carries the tempestuous histrionic tone of the melodrama into the rest of the action. Whereas the National's new Private Lives spells out the subtext for us - in an earnestly cosy way, as if we mightn't be able to guess at it ourselves - this production takes what's on the surface and twists it into fantastic hallucinatory shapes. The flippancy has a spikiness that is genuinely scary. It makes it very funny.
Nick Ormerod has designed a neo-Gothic hall with arched windows. The sound-effects of thunder and rain continue even through the interval. The performances have a neo-Gothic extravagance to match. To play the lead in a Coward, you need above all to convince us that you were born to inhabit Dressing Room No.1. It is clearly Geraldine McEwan's birthright. Her hilarious over-the-top performance as Judith Bliss starts off where most people end up. The entire repertoire of manipulative femininity is on display: the teasing tricks of an ageing soubrette (as she wags an unlit cigarette in someone's face) are combined with an uncanny ability to roll off a sofa and on to the floor without spilling a drop of her drink.
Twelve years ago, the Royal Court's production of Perdition was cancelled 48 hours before it opened. Jim Allen's play presents a fictional court case in which a Hungarian gynaecologist is accused, as a member of the Central Jewish Council, of collaborating with the Nazis in 1944. The story parallels a true one. But this isn't documentary realism. Themes emerge about the connections between anti-Semitism and Zionism that range beyond the confines of a legal transcript. As Yaron, the elderly man who brings the libel action, Morris Perry conveys a strong sense of having lived in two separate periods. His duel with Ian Flintoff's forceful and incisive barrister carries the intriguing possibility that he may actually want his cross-examination to be as tough as possible. The Union of Jewish Students were handing out a leaflet of protest at the entrance to the Gate; it was infinitely wiser than trying to ban the production.
`The Merchant of Venice': RNT Cottesloe, SE1 (0171 452 3000), booking to 11 September; `Hay Fever': Savoy, WC2 (0171 836 8888), booking to 14 August; `Perdition': Gate W11 (0171 229 0706) to 3 July