The Holy Terror, Duke of York's, London and Operation Wonderland, Latchmere, London

A night for the living dead

It's customary to begin theatre reviews with a neat summary of plot, but Simon Gray's revised play The Holy Terror is so scrappy it's hard to remember what it was supposed to be about. The protagonist Mark Melon emerges from behind the stage curtain and begins to address the audience as if he were talking to a branch of the Women's Institute in Chichester (a town he keeps confusing with Colchester. Oh, the hilarity.) He has been a publisher - "the enfant terrible of publishing... a great publisher who never missed a chance" - and he has had a breakdown.

The play then takes a ramble around Melon's rather uninteresting life. At great length, he confronts his son about not working for his A-levels. Then a stuffy old man at his publishing company objects to Melon's idea that they should publish sex manuals with titles like (cue incomprehensible audience laughter) Masturbation Without Shame.

Simon Gray, in a written introduction to the play, seems to believe The Holy Terror is about something else entirely. He thinks it is about a man who has an agreement to have an "open marriage" with his wife, but who goes mad when he suspects his wife of having an affair. The audience could be forgiven for missing this, since his wife is hardly mentioned in the play's first half, and when she does appear she is a one-dimensional bore.

The anecdotes about publishing that pad out the play until Melon's wife appears are entirely uninteresting. One of his writers develops paranoid schizophrenia, and the audience is encouraged to chuckle at his decision to write "an epic poem in Glaswegian patois". When a playwright is reduced to scraping for laughs by showing his audience the ramblings of somebody who is mentally ill, you know he's in trouble.

Occasionally Gray stumbles across an interesting theme - the tension between art and commerce, the misogyny of straight English men - but he always picks himself up, brushes himself down and carries on as if nothing has happened. The female characters are particularly dreadful. They are part of that special species of women that only exist in plays written by men with flagging libido in late middle-age. You know the type: with short skirts and long legs, they dedicate their lives to telling tubby middle-aged men how attractive they are. Oh, please.

The only mildly interesting reflection that could emerge from this play is about the nature of laughter in British theatres. Why do audiences strain and stretch themselves to laugh at material which is manifestly unfunny? At the press night, the audience chuckled away at material that would not even raise a smile on television. A character declares, "My boyfriend is called Wong. He's half-Chinese, half-Scottish." The audience roared. Hello? Did I miss the queue for free nitrous oxide on the way into the theatre?

Simon Callow does amazingly well to pour his near-nuclear energy into this coma patient of a play. Seeing such a great actor work such anorexic material is a bit like seeing a Formula One driver wheeze about in a Skoda: as Callow spasms and howls his way across the stage, you wonder why he is wasting his energy. He is reduced to milking the word "bonk" for laughs - for three agonising minutes. I wanted to cry.

Seeing The Holy Terror is less like watching a play than like one of those rambling conversations you sometimes find yourself trapped in on train journeys with old men who insist on telling you their life stories. It might be pleasantly diverting between York and Peterborough, but if I had paid £38.50 to hear them in the West End, I'd be furious.

For anybody who wants quality London theatre, they'll have to head far outside Theatreland, to a gorgeous little pub theatre in Battersea. Operation Wonderland is a strange, compelling parable about two people who work inside a vast neon theme park called Wonderland. Jeb is a cleaner who befriends the Blue Fairy - a woman who works in the grotto and tells children she can make their wishes come true.

It's a heightened world where the theme park divides families into green, amber and red on the basis of wealth, and is trying to establish "an independent legal constitution". This isn't as satirical as it might sound: there is a genuine dispute going on between Disney and the state of Florida about who has the right to police Disneyland. There have even been allegations that Disney staff deal with criminal matters - like the escape of a crocodile - without recourse to the Florida police.

Jeb and the Blue Fairy despise the dishonesty and hyper-commercialism rammed down children's throats. As an act of rebellion, they replace the artificial snow in the Winter Tour with elephant shit. When the excrement is sprayed across a group of dying children, Jeb feels guilty but the Blue Fairy insists, "We showed them what Wonderland is all about. You're being bought and manipulated to believe in this commercial magic. But it's elephant shit, and it stinks." As the plot spirals and the pair plan a suicide bombing on Wonderland's equivalent to the Magic Castle, the play becomes nightmarish. The Blue Fairy insists, "I'm sorry Jed. There's no chance we can make a difference. Blow a fucking great hole in Wonderland and they'll rebuild, turn it into a promotional video and sell remembrance popcorn on the crater." She insists she is doing it just "to see blood turning the whirly snowflakes red."

There are some misjudged attempts at a 9/11 parallel here - Osama bin Laden wasn't protesting against Disneyfication, folks. But as a reflection of what happens when commerce runs wild, when a mega-corporation is allowed to create its own artificial world and shut out all public space and accountability, it's totally compelling. If you are one of the many parents who has forced themselves for the sake of the kids to take an Easter trip to EuroDisney, this play is the hard slap in the face you need.

Kate Bassett returns next week

'The Holy Terror': Duke of York's, London WC2 (020 7836 5122), to 7 Aug; 'Operation Wonderland': Latchmere, London SW11 (020 7978 7040), to Sat