A cross between a mad professor and a Blue Peter presenter, the quantum physicist Dr Patrick Beer is giving a lecture on how to build a time machine. Essentials include a portable black-hole generator, a pair of oven gloves and a tape measure to show how far you have travelled. Oh, and a copy of Frenchman's Creek in case it is a long journey.
You won't need any reading matter during Greg McLaren's quirky one-man show, which has enough science to satisfy the physicists in the audience and enough artfulness to satisfy theatre-lovers. All of us would like to be able to travel back in time and change things, but it turns out that Beer has a particular and poignant reason for wanting to build a time machine.
The show needs a little more layering of heart with mind, guilt with black holes and love with gravity, but it is a wonderfully original 50 minutes - clever, comic and wistful with real potential for development.
· Until August 29. Box office: 0131-556 6550.
