MANY of us have brothers or sisters. A few people are twins – occasionally identical twins. Even rarer are triplets. But what if you had a clone?

How would you feel if there was another one of you? What if there were several clones of you? Would you want to meet your clone? How would you react if a clone took your place?

In Caryl Churchill’s thought-provoking play A Number, first produced in 2002 after the 1996 cloning of Dolly the sheep, the audience is forced to consider the concept of scientific manipulation of humanity.

Bernard – although his actual name is never mentioned, not even by his father – thinks he’s an only child. But, discovering the results of a science experiment that gave him several clones, he confronts his father... (or is he his real father?) Actors John and Lex Shrapnel are actual father and son, giving the play a convincing sharpness as the two – alone on stage for the one-hour duration – prod and poke in search of the truth.

What makes this production memorable is the unusual and creative set design by Tom Scutt. This is theatre-in-the-round with a disturbing difference.

The audience is split into four sides of a square, each seated behind a two-way mirror, the actors in a glass box with endless mirrored reflections of themselves fading clone-like into the distance. The device is claustrophobic, voyeuristic and brilliantly effective.

A Number runs until February 22.