Once the audience gets onto its wavelength, there are yelps of scandalised and delightedly incredulous laughter throughout Matthew Dunster's miraculously well-acted revival of this forgotten 1949 gem by Rodney Ackland.
This was a dramatist who was much tougher-minded, unconventional and influenced by the Russian way with tragicomedy (he adapted Bulgakov) than most of the other playwrights who were sidelined by the Royal Court revolution. His career effectively ended in 1952, when he was 44, with the disastrous (and unconscionable) critical reception of The Pink Room, his play set amongst the Bohemian flotsam and jetsam in a Soho drinking club in that strange period between VE Day and the Labour victory.
Before the Party is, contrastingly, set in leafy Surrey amidst the well-heeled middle-classes in 1949. Rationing is a bore, where those needful treats are concerned, but you can can get foie gras sent from America (“you mustn't spoil it for me by telling me how it's made”). And there are ways round the petrol restrictions which is just as well for the Skinner family who are preparing to go a social climbing lunchtime function that the strenuously huffy-stuffy lawyer father (Alex Price) can't afford to miss. He's up in front of the Conservative Party selection committee on the Monday.
Then, though, everything starts to go wrong. One of his daughters, back from Africa, insists on wearing pink rather than mourning and then, with Katherine Parkinson brilliantly using that built-in equivocation in her voice between chuckle and sob, she is goaded into telling them part of the devastating real reason she's a widow. Michelle Terry is hilarious as his other daughter whom romantic jealousy has turned into a glowering career snitch, prognathous of jaw, whose designs on the Golf Club hierarchy look equally doomed. Cook (apparently an unreconstructed Mosleyite) has locked one of the maids in a cupboard simply for being a Jewess. Oh and both the 13 year old daughter (excellent Emily Lane) and June Watson's movingly forthright elderly Nanny may have overheard the terrible revelation.
Part of the comedy flows from the way that, even when talk of murder, suicide, antisemitism et al silences this crew for a moment, heartless self-interest and fixation with social standing assert themselves afresh with undiminished vigour. The prejudices are ventilated with an outrageously blithe take-it-for-granted air. Stella Gonet is beyond praise as the mother who keeps up a running on what it is all doing to her stomach and director Dunster retains wondrous control of the play's calculated but tricky waverings of mood. Sheer spiky bliss.
To 11 May; 020 7359 4404