Aalst

The title Aalst refers to a city in Belgium that in 1999 was rocked by a double murder. A couple checked into a hotel with their seven-year-old son and infant daughter, and left as killers.

The Belgian media pored over every detail of the case, including the trial and subsequent life sentencing of the couple.

Director/designer Pol Heyvaert was inspired to produce a piece of theatre, but he and the producing company, Victoria, weathered a storm of criticism (and were threatened with a court injunction) before Aalst made it to the stage.

The mother of the dead children objected to Heyvaert's employment of both verbatim and imagined dialogue. Although names were changed, the play's title leaves little room for ambiguity about its subject matter.

Things are further complicated in the National Theatre of Scotland's new production, billed as a 'new version' by Duncan McLean. Like in a game of Chinese whispers, the contentious text has now been altered. Actors Kate Dickie and David McKay speak in Scottish dialect, and in Scottish accents. Unlike in the party game, retaining the essence of the play depends on subtlety rather than clarity.

The pair play Cathy and Michael Delaney, a couple who appear almost completely disconnected from the rest of society. Talking of their lives before the killings, they describe a relentlessly grim but financially comfortable existence facilitated by benefit fraud, petty theft and borrowing from irresponsible lenders.

That this production provokes laughter from the audience may seem surprising. The presence of humour shouldn't, however, be taken as a sign that Aalst takes its subject matter anything other than very, very seriously. The Delaneys answer questions posed by an unseen third party - the same technique that was effectively employed in The Arches Theatre Company's Tone Clusters. For the most part, what they say follows a perverse kind of logic. As care kids themselves, they didn't want their own offspring to have the same fate. As selfish individuals, they had no reason to believe that they themselves were capable of being loving, caring parents.

After the crime itself is dissected - with neither perpetrator flinching at describing the gruesome details - the voice explains that 'no serious psychiatric disorder' was found in either defendant. The true degree of premeditation involved is impossible to ascertain, and it seems unlikely that the real-life killers, acting on legal advice, will ever provide the answers.

The questioner is absent during the play's final conversation, presumably imagined, in which Kathy and Michael appear to be preparing for a parole hearing. The extent of their alienation is chillingly revealed as they struggle to find words that might resonate with an audience of 'normal' people, and therefore help to reduce their sentences.

The most difficult question posed by Aalst does not relate specifically to this couple, their crimes or their sentences. It asks what, if anything, can be done about people who are officially both sane and intelligent but who simply do not care about others. Can we blame 'society' when a crime is committed by people who cannot grasp that very concept? And how can we expect compassion, empathy or remorse from people who genuinely do not understand the meanings of those words?

Not exactly an entertaining hour's theatre, then, but rather a bold, gripping exploration that offers no easy answers.