BEING cooped up in the middle of a building site has brought out the dark side in the Lyric Hammersmith's company of writers, if the third show in its Secret Theatre season is anything to go by.

Having eased us gently into this lucky dip style project with a couple of classics, the scribes have now been allowed to unleash their feverish imaginations on an unsuspecting audience.

As with my previous review, of what was a powerfully unsettling production of A Streetcar Named Desire, I'm going to give you a chance to look away now if you don't want to know the score.

If you weren't already aware, Secret Theatre is both a neat way to keep the Lyric's creative heart beating while its body undergoes major surgery, and a challenge to the increasing commodification of the arts.

An impressive company of actors, writers and other creatives have been beavering away, amid the drilling and hammering, on a series of new and classic plays. Your part is to buy your tickets blind and turn up with an open mind. If you want to play the game, you might not want to read on.

Still with me? Well, Chamber Piece is a new play by Caroline Bird, writer of the well-received modern day adaptation of The Trojan Women, which premiered at Notting Hill's Gate Theatre last year.

Set in the near future, when the death penalty has been reinstated in the UK, an audience looks on as a convicted criminal awaits his fate.

The lethal drugs are administered and appear to have done their job, but all hell breaks loose when the wardens carrying out the dirty deed realise the offender's heart is still beating.

The dark side of the assembled cast, from the fiercely ambitious governor to the weedy medic whose ethics have a lower case 'e', emerges as the building is put in lock down.

Bird's script is scabrously witty, plumbing the depths of gloriously bad taste as she delights in the character assassination of each of her creations in turn.

It's the theatrical equivalent of picking a scab; you know you shouldn't, but you somehow can't help yourself.

The set-up is ingenious and there's no holding back when it comes to the gallows humour, but, even in what's essentially a very adult pantomime, I felt the characters could have done with more fleshing out.

Sergo Vares, who shone as the menacing Stanley Kowalski in A Streetcar Named Desire, is excellent again as a wishy washy spiritual advisor on the verge of a breakdown.

But he's cast aside too quickly, like a discarded lover, once his comic potential's been mined. He's not the only one, either, and I couldn't help wishing Bird would commit a bit more to her characters.

Entertaining as it is, that's ultimately the play's downfall. Entering the end game, having had her fun, the playwright begins scrambling around for a message. She suffers from the same problem as her characters in struggling to finish the job.

* Show 3 is at the Lyric Hammersmith until November 5. For tickets, priced £15, visit www.lyric.co.uk or call the box office on 020 8741 6850.