Comedians Phill Jupitus and Andre Vincent are forever being mistaken for one another. So it is a perfectly logical step (in the Lewis Carroll sense) to stage a play in which they alternate the roles of Tweedledum and Tweedledee for each performance. The upshot is an entertaining confection clearly derived from Waiting for Godot and Rosencrantz and Guildenstern Are Dead. Jupitus and Vincent's Dum and Dee are the seekers in all of us, questioning the point of their endless wait for Alice, wondering if she will ever turn up again.
Novice playwrights they may be, but Jupitus and Vincent's script has a deft circularity to it: Dum and Dee have essentially swapped personalities by the end of the hour. To begin with, Jupitus is underpowered as the prissy Dum, rehearsing his lines for Alice's arrival while Dee kicks back with a cup of tea. There is some droll sparring between the pair as the story goes nowhere fast, including one hilarious routine in which Dee produces a stork, a fork and a cork from his picnic hamper, breaking Dum's vow of silence by ruthlessly exploiting his love of rhyme.
Things turn meaningful when Dum makes a virgin trip to the outside world. He returns with doleful news that shakes their sense of self ("We were created by a paedophile?") and explains their redundancy (no one reads library books any more). There are times when the script devolves into a seminar on the characters' origins; how Dum gleaned this literary history, like the details of his whole trip, is not made clear. But Vincent communicates Dee's spiritual crisis funnily and plaintively ("Why weren't we in the first book? Weren't we good enough?"), and there is a sweet detour into Dum's passion for the girl who last read them, 68 years ago.
It's not comedy Wonderland, but it is an intriguing fix of nonsense existentialism nevertheless.
· Until August 26. Box office: 0131-623 3030.
