Nick Payne is the author of thrillingly, mind-expanding plays that tackle such daunting subjects as parallel universes (in the all-conquering Constellations) and neuroscience (Incognito). He makes fools of anyone who holds the lazy assumption that science is an emotionally barren territory.

This latest is set in the near future when it is possible to cure brain disease by removing affected cells and replacing them with a synthetic alternative. Functions, whether speech or tying shoelaces, are saved. But memory is lost.

Zoe Wanamaker is Lorna, an Alzheimer's sufferer. Barbara Flynn is Carrie, her wife, who has to grapple with the dilemma of allowing Nina Sosanya's infuriatingly clinical doctor to rid Lorna of the disease that will save her life and kill all memory of their relationship. Payne uses a not so innovative structure to tell his story. I won't reveal it but the issues he explores are pretty obvious. Charlie Kaufman's brilliant movie Eternal Sunshine of the Spotless Mind covered similar territory much more effectively.