John has never met anyone like Kay. When the moon is in the right phase, she is magnetic and amazingly alive. But when the darkness closes in, she is lost to another world, a world in which John does not belong.

One man's struggle to love, support and live with someone suffering from a psychological condition is beautifully captured with humour and pathos in this extraordinary new play by Mark Haddon, the author of The Curious Incident of The Dog in the Night-Time and A Spot of Bother.