Questions about identity run through director Neil Bartlett's work like the word 'Blackpool' through a stick of rock. Eight years ago his production of Marivaux's The Dispute at the RSC’s Other Place, examined the issue of nature versus nurture, so, on paper at least, Twelfth Night or What you Will, seems tailor-made for him.

In practice, however, the production, which boasts a star appearance by US comic actor John Lithgow as Malvolio, falls disappointingly flat, prompting uncomfortable memories of Lindsay Posner's drear outing here six years ago. Like Posner, Bartlett sets the play in Edwardian England. Like Posner, Bartlett manages to lose most of the laughter en route in his "exploration of sexual ambiguity," as the RSC remarked at the time.

Bartlett acknowledges the artifice of the evening from the off. Feste, sat behind a grand piano, announces the start of proceedings which take place on a thrust stage marked out with flickering lightbulbs. The stage is dark, empty, except for a series of mirrors in which members of the cast are invited to view themselves.

The production begins strongly. Jason Merrells is an ardent and physical Orsino, a man in love with the idea of love; Lithgow is imperious from the off as Olivia's dour manservant; best of all, however, is Chris New, as Viola who shows just why he was nominated for Newcomer of the Year in the Whatsonstage.com Theatregoer’s Choice Awards 2006 for his role in Bent .

Playing a woman who in turn plays a man, New is superbly deft and delicate, richly deserving of further accolades. And Bartlett's doubling, as it were, casting a man as a woman, pays dividends. Unfortunately the decision to cast women in the roles of Sir Toby Belch and Sir Andrew Aguecheek, fails abysmally. Their scenes together, glorious in other hands and wonderfully comic, here resemble a bad French and Saunders sketch.

There's no denying the intelligence behind the production but it lacks heart. It's not just the laughter that too often goes astray, it's the pathos too. Aguecheek's heartfelt, "I was adored once too", passes for naught. It would be unfair, though, to class the production as a total failure, given the strength of some of the individual performances. Lithgow's performance during the letter scene in particular, is a joy and his inaugural attempt at a smile, showstopping. It's just a shame that these performances are let down by the overall production

- Pete Wood