The Night Shift, Traverse Theatre, Edinburgh,

In Lara's case, it's a recurring nightmare - a mysterious flight of stairs and something terrifying behind a door - that takes her on sleepwalking expeditions and leaves her in a cold sweat. It also scares the life out of her boyfriend. She suffers from a sleep disorder, parasomnia, and - wouldn't you know - it all goes back to a traumatic childhood experience. This incident, re-run several times as bad dreams invariably are, links Lara and her past to a parallel tale.

With one swish of a gigantic white curtain we cut to another couple, played by the same two hard-working actors, Catherine Dyson and Jason Thorpe. Here Dyson plays an inexperienced counsellor trying to untie some of the knots in the mind of a man in a secure unit. Assuming the nocturnal name of Luna, it is she, rather than her alcoholic client, who is searching for the key to peace of mind. She feels her way in the darkness - we, the audience, just hope that light will eventually dawn. There's some concentrated acting from Dyson and Thorpe under Murphy's noirish direction, a quirkiness in the writing and enough intrigue to keep you awake.

To 28 August (0131-228 1404); then at BAC, London SW11, to 25 September (020-7223 2223)