A Number review: Paapa Essiedu is a cloned son in this haunting chamber piece

Caryl Churchill’s 2002 play reads like a proto-Black Mirror. Written in the wake of Dolly the sheep, it is about a son (Paapa Essiedu) who discovers that he has been cloned from the firstborn of his father (Lennie James) and that he may be one of up to 20 clones, thanks to a feckless doctor. The dystopia is clear, but savvy revivals of this modern classic tend to focus less on its sci-fi trappings and instead use it as a metaphor for parental responsibility, creating a strange, haunting chamber piece about how little we will ever truly know our flesh and blood.

Churchill’s text remains a gift, 20 years on: it is elliptical and eerie, full of half-finished sentences and snatches of savagery alongside banality. Director Lyndsey Turner makes an effort to ground it, pulling away from its sharper absurdist edges. As a result, this production at the Old Vic feels more legible, but it also skates over some of the quiet linguistic recurrences that play out like musical motifs – though Essiedu, who has always been an excellent verse speaker, finds a pleasing elastic cadence in the dialogue.

As Salter, James starts out by speaking in absolutes: “I am your father,” he tells Bernard 1, but this certainty dissolves the more his cascading lies catch up with him. Is he really a father if he’d abandon his son and start again with a carbon copy? And is there not something tempting about the idea of starting over with your children if you could? It is a play constructed out of contradictions: much like people, numbers are both variables and fixed entities. Salter can tell a truth and a lie within the same sentence, the clones both are his sons and aren’t. It comes through in the design too: Es Devlin’s set is both naturalistic and uncanny; setting the action in a lifelike living room that is bathed in an ominous crimson hue.

James plays Salter with an intriguing placidity: he is affable and loving towards his sons (Bernard 1 in particular) but he has an absent-minded cruelty, too. You can never quite tell how much Salter really knows about the clones – whether he is always holding back more than he admits, or if he has buried his head in the ground out of guilt. This kind of psychological complexity is compelling, but it’s hard to find the ground in James’s occasionally imprecise performance, in a role which needs to anchor the play. In a showier role, Essiedu, a hugely dexterous actor, must play both Cain and Abel: as Bernard 2, he is genial and boyish, stuffing his hands inside his sleeves and shuffling about his father’s flat, and as Bernard 1, he is coiled like a snake, frighteningly brittle. It is testament to both Essiedu’s skill and Turner’s deft hand that this does not play out as an extended acting exercise but rather as a series of delicately drawn character studies.

Turner’s production as a whole, however, can be a little too clean for a play so concerned with moral messiness: indeed, she wraps up an enigmatic final scene a mite tidily. A Number should haunt the mind long after it ends, but instead feels like it gets snuffed out.

‘A Number’ runs at the Old Vic until 19 March