There's something different about Marion and Geoff onstage. Perhaps it's that there's no mention of Marion, or Geoff. This is comic actor Rob Brydon's first visit to the fringe, in the character of doggedly cheerful divorcee Keith Barrett. Keith is presenting, "not a show, but a talk" on the subject of marital break-up. "Please," he warns us, "don't expect anything too good."
What a get-out clause! When Brydon/Barrett gets heckled, he has no slick comebacks: "I'm trying to think of one," he says, in that ineffectual Welsh lilt, "but I can't." Easy for Brydon, then, and just as much fun for us - cuddly fecklessness is part of Barrett's appeal. Otherwise, Brydon wears the mantle of Barrett quite loosely around his shoulders in the live arena. This is a more light-hearted affair than the subtle, downbeat TV show; and (especially when playing the crowd) the smarter, more cynical Brydon occasionally peeks from under his alter ego's carapace.
But as Barrett, he can be rude, and still seem sweetly innocent. He can provoke the natives: when discussing the 17% increase in the Scottish suicide rate since 1990 ("maybe it's a sense of shame for the John Leslie farrago") he can trill "there's a noose loose aboot the hoose" with impunity. Highlight of the show is his interminable vote-count when polling our responses to his divorce quiz. He's mind-numbingly jobsworth about it; a show of hands has never been so exasperatingly funny. If they could see him now, his "little smashers", Rhys and Alun, would be proud.
· Until August 17. Box office: 0131-226 2428.