It is probably a bit glib to wonder whether it is now compulsory to cast a father and son in Caryl Churchill’s dystopian cloning drama. Timothy West and his son Samuel were widely acclaimed when they assumed the roles at Sheffield in 2006 and again in London four years later.
Now it is the turn of George and Niall Costigan.
It is easy to see why keeping it in the family, so to speak, brings an alluring something to this intense, brooding play.
What other relationships can glower and fizzle so? With whom else is a conversation so often riding on a knife edge where the tiniest of slights – real or perceived – can elicit sudden bouts of bad blood-letting?
Father and son are so much the product of each other’s expectations and failings that any director will surely want to bottle that and serve up the intoxicating draught live on stage.
The Costigans do a very decent job – especially father George looking back through the bottom of a vodka glass at a life marred by tragedy and an extraordinary experiment in human manipulation.
Niall has the tougher task to finesse the differences between the three sons, two of whom are the clones of an ill-starred first born.
He is more convincing as the nice, thoughtful copies rather than the evil original but there is clarity to the performance which steers the viewer through the occasionally confusing structure and dialogue and the hour crackles away enjoyably.
At the beginning of the century when the world was worrying about the fallout from Dolly the Sheep, GM crops and the long term impact unfettered tampering with DNA, A Number was hailed as an important and timely play.
It is certainly a weighty piece of work examining core questions of who we are and how we come to be that person – a theme most brilliantly examined in the final scene as father and son number three struggle to get to the nub of the issue.
But perhaps the subject matter falls a victim of being too recent in the memory to surprise us with its prescience whilst not sufficiently contemporaneous to be cutting edge.
Today questions of identity are as much tied up in our worries over big data and internet surveillance as they are about the runaway ethics of biology.
To 24 May.