The relationship between silly chump Bertie Wooster and his inscrutable, unflappable manservant Jeeves is based on the latter saving the former in a succession of scrapes, social faux pas, linguistic minefields and sartorial blunders.

Translating that energy into a performance format proves a rum old business: this new three-hander by Robert and David Goodale, hyper-inventively directed by Sean Foley, goes down the route of meta-theatricality, laying a sort of 39 Steps approach across the improvisatory template of The Play What I Wrote.

Stephen Mangan's red-jacketed Wooster, baring his teeth and braying like a demented donkey, is therefore lumbered with an audience to whom, on an empty and under-populated stage, he is obliged to recount a drastically filleted but basically accurate version of P G Wodehouse's 1938 comedy classic The Code of the Woosters.

Our hero, attended and supported by Matthew Macfadyen's suave and pale-featured Jeeves, must therefore decamp from Berkeley Square to Totleigh Towers, Glos, retrieve a silver cow-creamer for Aunt Dahlia and salvage the impending nuptials of best pals Gussie Fink-Nottle and Madeline Bassett, while staving off the intrusions of the dastardly crypto-fascist Roderick Spode.

The show's brilliant joke is that the implacable Jeeves, whose interventions are only implied at leisure in the original, is translated into a quick-change artist in the cause of smoothing out the creases, and the crises, in the story.

The joke is admittedly diluted in the necessity of a back-up player, the squirrely servant Seppings, played by a grumpy little Mark Hadfield, playing all the parts Jeeves can't quite reach. But the manoeuvre also provides a clever variation on the delirious dynamic of Toby Jones' third party sucker in The Play What I Wrote, dividing the responsibility of role-playing and gradually defining Bertie as the real outsider in his own narrative.

Macfadyen's blank canvas - this strikingly good-looking Jeeves avoids both the oleaginous creepiness of Dennis Price and the eccentric muttering of Michael Hordern - is vividly occupied not only by a goggle-eyed Gussie, but also by an absurdly seductive Madeline (in a lampshade and half a curtain), as well as her father Sir Watkyn (white bushy hairpiece and thrusting pipe) and his ward, Stiffy Byng, a sort of low-rent Lauren Bacall in a purple frock.

The complications of the plot are therefore complemented in the accumulations of absurd characterisation. In one scene, pa Bassett and offspring are simultaneously occupied in a single split costume, while the baleful Seppings, ferreting around the stage like a prognathous truffle-hound, is obliged to "voice" his monumental Spode (Hitler moustache, eight-foot leather coat worn while standing on a stool or chair) with his bow-legged, taffeta-dressed Aunt Dahlia, who increasingly resembles a dismal tangerine.

Foley's production probably errs on the side of too much scenic and stage-effects business, as if covering all options without trusting them equally. But it seems churlish to complain about a show that is so fertile and generous in its presentation, and so spiritedly performed. It just needs a little more settling down, and a little more light and shade, so the audience doesn't feel "got at" all the time. And no, I don't think we misheard Harold "Stinker" Pinker as Harold Pinter, did we?

The sets and costumes are the outstanding work of Alice Power, and there's even a curtain-call bonus, a la Shakespeare's Globe, with a brilliantly executed Charleston trio, choreographed by Carrie-Anne Ingrouille. Crikey, Jeeves, how did we all do that?