WILLIAM Golding's iconic Lord Of The Flies reminded us that childhood and innocence don't necessarily go together.

Dennis Kelly's play DNA visits the same territory with a chilling tale of a group of comfortably set up, far from dysfunctional teenagers, seemingly with the world before them, who mindlessly indulge in cruel peer bullying.

The result is that they hound schoolmate Adam to what must surely be his inevitable death falling down what appears to be a well. Group leader Phil incredibly quickly devises an intricate plan involving tortuous lying and cleverly manipulated DNA evidence which removes them from suspicion, and results in the conviction of an innocent man. Even so, the gang's cohesive strength gradually disintegrates, one of them ending permanently traumatised.

Staged with an impressive projection and video design, Kelly's narrative is elaborately devised and darkly disturbing, with sharp dialogue. It's morally challenging and displays a commanding understanding of group mentality and power politics. It also provides actors with some really meaty roles in which to sink their teeth.

James Alexandrou as icy-nerved Phil has pathological self control which draws his confreres to him as with an irresistible magnet. The menace he creates owes no small degree to his chilling quality of silent stillness. Leah Brotherhead provides light relief and bids to steal the show as an incessant chatterbox, muzzy-headed but basically good hearted.

The play has now been included as a core set text on the GCSE English syllabus, being studied by 400,000 students each year, so clearly it is regarded as having considerable merit. But as a piece of theatre I had major problems. During its uninterrupted playing time the story gripped me, though the final shock twist hardly came as a surprise. But immediately afterwards I realised I didn't believe a word of it.

And my acceptance of the narrative's farfetchedness, which surely would have been dismantled by competent police procedures, was not helped by the actors, fine though they were, being too old for their roles. But while it lasted...