Not since Festen has the West End offered such a searing theatrical experience. But, where the Danish play dealt with vicious parental abuse, David Harrower's work, seen briefly at the Edinburgh Festival in Peter Stein's magisterial production, is about two people destroyed by an illicit love. The setting is a bleak factory recreation room where 56-year-old Ray is confronted by 27-year-old Una with whom 15 years previously he had a sexual affair.
But, without exculpating Ray, Harrower explores the human complexities that lie behind the term "paedophilia"; and, not unlike Nabokov in Lolita, he suggests that innocence and experience are relative terms. What Ray did was unforgivable; yet the play also makes clear that the 12-year-old Una was afflicted by an obsession as great as his own, and that closure in such a relationship is not easily achieved.
It is a play that poses endless questions about the dark, uncontrollable power of desire. And, even more than in Edinburgh, I was bowled over by the performances. Jodhi May captures brilliantly the tension in Una between revenge and fulfilment: a part of her seeks the humiliation of her ex-lover - but, in her black stockings and pink skirt, she is clearly engaged in an act of taunting provocation. She also brings extraordinary pathos to the line where, describing her apparent abandonment by Ray, she claims "you left me in love". And Roger Allam, his heavy features acquiring a crumpled, seamed quality, superbly conveys the progressive disintegration of a man forced to confront his past guilt.
But Stein's breathtaking production also brings to a modern play the minute detail which he normally reserves for the classics. Behind the frosted glass of Ferdinand Wogerbauer's set we constantly see the peering faces of passing workers whose voyeuristic fascination mimics our own. The debris-strewn floor reflects the inner chaos of the characters themselves. And Ferdinando Nicci's soundscape is as complex as in any of Stein's Chekhov productions: Una's description of her abandonment in Tynemouth in evoked through mewing gulls and pealing bells and when we finally hear the off-stage cries of a young child the sound freezes the blood.
Harrower's two-hour play puts us through the wringer. But in doing so it forces us to examine our reflex moral responses.
We all know where we stand on adult-child relationships; but when Ray tells Una that "you knew more about love than I did" you realise he may be expressing a disquieting, normally unspoken truth.
· Until May 13. Box office: 0870 950 0920