Amato Saltone, Shunt Vaults, London

Ahhh! I'm lost in my very own film noir

In an arts world continually required to prove its "accessibility" it's refreshing to go to a play where you can't actually find the theatre. And where, once inside the theatre, you can't find... the theatre.

Of course Shunt don't do "plays", as anyone who saw this company's previous work Dance Bear Dance or Tropicana will know. They do "events" - perhaps best described as efficiently-run Happenings - and they do them very well. Amato Saltone takes place in Shunt's home underneath London Bridge station, the entrance nestling all-too unobtrusively between the ticket machines and gourmet sausage outlets.

Once through the door, you make your way cautiously up the long, dark arched space that extends dimly into the distance, how far it's hard to say. No signs, no helpful ushers. It's a relief simply to make it to the bar, a feeling which expands into contentment with the realisation that you are in what is undoubtedly the coolest theatre bar in the capital, an echo-y chamber scattered with makeshift tables and random chairs, and peopled with the sort of young trendies more often seen in Shoreditch than Shaftesbury Avenue.

While this might seem irrelevant - what about the show? - it's very much to the point. All theatre is about manipulation of the audience and, by the time you wander, with the throng, into the "penthouse" where the show begins, swigging from your second bottle of beer and nattering with your mates, Shunt have you entirely in the palm of their hand.

To describe what follows would not only be unsporting, but also unfeasible, as the audience is repeatedly sub-divided, meaning you don't see what others see. Suffice it to say the audience make up the guests at a private party of a decidedly sexual nature ("the safe word for today is 'quail'," advises one of the uniformed staff members) and, in their reaction to events, make up large parts of the show.

So, yes, I wore my party hat, answered when my brand-new name was called - just before the announced power cut plunged the penthouse into darkness and we witnessed the "act of unspeakable violence" - and, later, passed on a phone message to the shell-shocked Louise Bliss. For you, it will be different.

Shunt's declared inspiration for the show is the pulp fiction of Cornell Woolrich (whose stories were adapted for both Rear Window and The Bride Wore Black) but this is noir filtered through a surrealist sensibility. If you've sat happily bewildered through David Lynch's Lost Highway or Mulholland Drive then you'll be right at home here, enjoying the ebb and flow of anticipation and disappointment, certainty and confounded expectation.

But be warned. This is no more "inclusive" theatre than it is "accessible". If you're not part of the young, hip throng described above, you may find yourself bewildered right into indifference. Partly because, as well as its audience, they and their lifestyle are its targets. For all its grim humour, and tangential references to urban catastrophe, the only truly unsettling aspect of Amato Saltone is the suggestion that the scenesters of today are as soulless as the swingers of their parents' generation.

To 26 March, 020 7452 3000