Woyzeck, Barbican, London

Water, water everywhere in this astonishing Icelandic production of Georg Büchner's 1837 fragmentary masterpiece, the latest offering in the "Young Genius" season presented by the Barbican and the Young Vic.

Generally regarded as the first working-class tragedy, and certainly the precursor, by a century, of German Expressionism, the most striking aspect of Woyzeck is its vivid detail as the eponymous young soldier disappears inside his own paranoid fantasies, unable to cope with "one damned thing after another".

The actors from Reykjavic's Vesturport Theatre speak in English, so the story, such as it is, emerges clearly enough, even if the detail is a little blurred. But they are all metaphorically consumed in the amniotic fluid of the play's imaginative power, which derives firstly from a battery of industrial water pipes, and secondly from a stage-wide fish tank, the stream into which Woyzeck and his murdered girlfriend Marie swim ecstatically to oblivion.

In the play, Woyzeck disappears ambiguously into the lake at the end, looking for the knife with which he killed Marie. Here, the drowning is an underwater escape from the grinding pressure of the everyday world. What makes Woyzeck so disturbing - and I was terrified by this version - is the sense that Woyzeck's predicament is so needless and yet so comprehensible. Added poignancy comes, of course, with the knowledge that Büchner died aged just 23, before completing it.

The Woyzeck of Ingvar E Sigurdsson is a huge man with no outlet for his energy but a limitless capacity to be duped. Thus, instead of being the timid army barber of the script, he is a prime specimen for the weird experiments in the water factory, the fiefdom, it turns out, of the Drum Major who cuckolds him. This veritable übermensch flies out over the audience on a huge trapeze that seems as if it might drag the entire set after it and batter us all, let alone Woyzeck, into submission.

Something about this play attracts unexpected musical treatment. Robert Wilson' spellbinding Scandinavian production at the Barbican three years ago had some achingly beautiful, Kurt Weill-ian songs by Tom Waits and Kathleen Brennan. This one has haunting numbers by Nick Cave and Warren Ellis of the Bad Seeds, which reflect both Woyzeck's misery and the Drum Major's ascendancy.

That symbiotic relationship between the downtrodden and the high-flying, turning on the axis of Marie's eroticism, creates a new element in the drama that doesn't exist in Büchner. I still yearn to see the play staged with the devastating simplicity I recall in a Newcastle production by Keith Hack, and have read about in a Stockholm version by Ingmar Bergman. But I can't really belabour Gisli Orn Gardarsson's production for its daring when simplicity would no doubt be the easier option.

To 22 October (0845 120 7518)