Shoreditch Madonna, Soho Theatre, London

Michael, Nick and Hodge are artist-entrepreneurs who run a derelict art space in Shoreditch. They are organising a weekend forum where the guest of honour will be Devlin, a once-lionised but now broken and dishevelled artist. Devlin is dogged by tragedy. His daughter drowned and he's been in prison for having sex with a fifteen-year-old.

And now Charlie, a junkie who was a childhood friend of his daughter and a protégé, has hanged himself. Intercut scenes in a Streatham bedsit show us the latter's girlfriend, Christina, in a trance of grief. Further confusion is provided by the reappearance of Martha, aformer lover of Devlin's.

The piece is given a slick, stylish premiere by Sean Mathias and the two leads do all they can. Francesca Annis is witty and wounded as Martha and Leigh Lawson provides the right degree of calculation in Devlin's tramp-like spent genius routine.

And yet I found it hard to believe. Partly, it's a matter of the ham-fisted plotting. To assist the switchto a more hopeful mood, Devlin has a twelve-year-old son sprung on him at the end and, out of the blue, Martha enjoys a night of bliss with the hitherto least noticed of the artist-entrepreneurs. The link between Shoreditch and Streatham feels forged: in a very contrived arrangement, another of the artists features in a therapeutic video for Christina, with whom he falls in love.

Partly, the spurious atmosphere arises from the weirdly inauthentic dialogue. Here's Devlin telling Christina about his daughter's death: "I was on the beach reading the Marquis de Sade. I was so concentrated on hiding my erection that I didn't notice what was going on. People carried her to me. And I knew something epic had happened. The sky had changed colour. Literally. A blue I had never seen before. She'd be your age now..." Yes, yes, we know he's self-absorbed, but this is surely above and beyond the call of duty. I'm afraid Shoreditch Madonna calls to mind another of Devlin's phrases: "boredom on a plinth".

Until 6 August (0870 429 6883)