The Glass Room, Hampstead Theatre, London <!-- none onestar twostar threestar fourstar fivestar -->

Ryan Craig is one of the founding members of the monsterist group of playwrights who believe that plays should be on a large scale and deal with great themes. Having tackled the Arab-Israeli conflict in What We Did to Weinstein last year (gaining an Evening Standard most promising playwright nomination), Craig has turned his pen to perhaps the largest theme of all - freedom of speech.

His hero is Myles, a "passionless, peripatetic" human-rights lawyer hired to defend the notorious historian and Holocaust denier Elena Manion. In his personal life, Myles is plagued by his bolshy, twentysomething live-in landlady Tara and his opinionated Jewish father Pete.

It's all achingly zeitgeisty, inspired by February's riots over the Danish cartoons about Islam, the imprisonment of David Irving and the new Racial and Religious Hatred Bill.

Things get off to an impressive start, with some tautly written banter between the two housemates - Myles's complaint that Tara's bedroom antics make "ripples in his cocoa" elicits roars of laughter - but would anyone really look at a CD collection and say: "Arctic Monkeys. Coldplay. Snow Patrol. It's a pretty frosty assortment."?

There's a cleverly gentle introduction to Elena - a nicely waspish Sian Thomas sporting a terrifying helmet of hair and sharp tailoring - as she talks seductively to Myles about "PC gone mad".

After these initial scenes, the play loses momentum before sputtering to a rather lacklustre conclusion. Daniel Weyman subtly captures Myles's increasing struggle to reconcile his heritage, profession and beliefs with his client's increasingly monstrous behaviour. Thomas is impressive as she becomes whipped up by her own hype and rhetoric, but she is ultimately too hateful to be interesting. The antics of Tara (Emma Cunniffe) become merely tiresome and overly stagey.

Craig is a promising talent and the kinks in the play - 20 minutes too long, with an irritating tendency to end every scene on a portentous cliffhanger - can be ironed out. He raises erudite points about free speech and the slippery nature of history and truth, but so keen is he not to reach any conclusions that he wrangles each argument to its extreme.

To 23 December (020-7722 9301)