Kay Adshead is a passionate writer whose last play, The Bogus Woman, was a rivetting tale of the Kafkaesque nightmare confronting an asylum seeker. But while her new play, appearing in rep with Tariq Ali's The Illustrious Corpse, raises our awareness of the dangers of the psycho-pharmaceutical industry, it offers an odd mix of clinical specificity and dystopian vagueness. Students of Pinter's The Hothouse and Joe Penhall's Blue/Orange will be familiar with the basic premise. In a London treatment centre an old hobo called Pongo, with 30 years spent on the streets, is part of a scientifically controlled experiment. Through a diet of drugs, he is slowly being "cured" of his rage. Under the supervision of a doctor and psychiatric nurse his natural intelligence starts to shines through but, after a bizarre swan killing, the treatment is intensified, reducing him to the state of a vegetable.
Adshead raises a host of important questions. Are we in danger of treating nonconformity as an illness? Are calmative drugs automatically beneficial? And at what point is it right to release damaged people back into the community? There is compassionate treatment here about a 70-year-old man still haunted by the death of his mother and so starved of sexual and emotional experience that he is romantically obsessed by the female doctor.
As long as the play deals with the ethics of using "social rejects" as scientific guinea-pigs it is fascinating. But where Adshead comes unstuck is in her evocation of the society.
For a start she overloads the play by having the male nurse moonlighting as a chauvinist, night-time comic, and by revealing the doctor to be a bounced Czech traumatised by memories of Soviet invasion. She also suggests that the entire country is in the grip of an endless war and that parks have been sealed off to protesters after mounted police have trampled people to death.
By overstating her case, Adshead eventually weakens it. It is perfectly proper to draw attention to the threat of the pharmaceutical giants and of calmative drugs being used on social misfits. But, instead of dealing with the specifics of the Iraq war protests, she paints a fuzzy picture of England as a nightmarish tyranny.
She is heavily indebted to Lisa Goldman's production and to the understated performances of Fiona Bell as the doctor, Richard Owens as the neutralised patient, and Mark Monero as the nurse. But while I can buy the idea of an England where vital liberties are at risk, I crave chapter and verse rather than cloudy intimations of impending apocalypse.
· Until September 27. Box office: 020-7478 0100
