Gate Theatre, London

Last Wednesday was Liza Doolittle Day, as set down in My Fair Lady: "Next week on the 20th of May/ I declare Liza Doolittle Day ..." (from "Just You Wait, Henry Higgins"). With the mind turning on such things, it was interesting last week to come across another heroine who first saw the light of day in the same year as Shaw's flower-girl, 1912. Frank Wedekind's in outline resembles Pygmalion: both have as their central figure a young woman who is raised out of her narrow, miserable existence by the intervention of a male patron, and who, having found independence, turns the tables on him.

The resemblance is close enough to give you some clues to the the state of mind of males in the early years of the century; but what is more striking is the difference between the two plays. Where Shaw is crafted, asexual and polemical, essentially an argument about class translated into dramatic terms, Wedekind is messy, passionate and thoroughly theatrical: it's an argument, but one that it's impossible to imagine being stated in any other terms. Like Wedekind's masterpiece Spring Awakening, it is a disorienting mix of naturalism and bizarre expressionist gestures; it is also, again like Spring Awakening, remarkably frank about sex, probably explaining why it has never been performed in this country before. But as Georgina Van Welie's staging makes clear, those things that made it outrageous in its day now make it surprisingly modern.

Throughout the play, Wedekind delights in shooting down expectations. He begins with a stereotypical romantic tableau - a young woman, (Lydzia Englert), sitting at home with her mother as the sun goes down, awaiting a visit from her lover. But then he turns the situation upside down, as it emerges that 's interest in her young man is purely rational and sexual - she has seduced him as a way of losing her innocence. Having set her up as a Faust figure, thirsting for knowledge, Wedekind introduces his Mephistopheles, Veit Kunz (played by Christopher Bowen as a smirking, charismatic devil with more than a touch of Michael Barrymore about him). He climbs in through 's window and offers her musical stardom and the chance to enjoy two years living as a man, if she then consents to become his chattel.

In the event, however, she asserts her independence by welshing on the deal, throwing him over for another lover, and then deserts both of them to become a mother on her own terms. In the final scene we see her transformed into a Madonna - though one with a knowing, wicked smile - and perhaps ready to settle down with her equivalent of Eliza Doolittle's Freddie, a meek young artist who adores her.

The production, hovering in some zone between reality and caricature, is not without its flaws and its longueurs, but Eleanor Brown's sharp adaptation and the double-act between Bowen and Englert compensates for that. Englert in particular, some oddities of delivery aside, displays an acute intelligence, maturing in the course of the play from adolescent awkwardness to mature self-possession; it helps that she is stunningly good-looking. Never easily pinned down but always intriguing, emerges as a treat we have done without for far too long.

plays until 6 June

Booking: 0171 229 0706