Rob Brydon: Marion & Geoff, Assembly Rooms, Music Hall, Edinburgh

Divorce: it's a good laugh

I've never been a particular fan of Rob Brydon's acclaimed comedy Marion and Geoff, finding the situation (lonely Welshman talks to camera while sat in front seat of car) all too claustrophobic, even though its creators must be applauded for getting half-hour episodes out of such an unlikely format.

But the appearance of Brydon's unfortunate invention Keith Barrett on stage, as ever sporting his chauffeur's uniform, is a revelation. By nature, Keith is an optimist. An idiot, yes, but an optimist terrified to see the worst in people, in case it should upset his own clearly delineated world. He might have lost his wife and two "little smashers" to an apparently "wonderful" man, but it won't affect his desperately sunny outlook. It's only five minutes into the show before he informs us he's "never been happier", a fatal sign. He also declares "I'm not a showman, I'm not a comedian," and that's equally untrue.

The newly confident Keith leads the crowd through a lecture entitled "Making Divorce Work", proudly showing off a set of statistics which explain how Wales's suicide rate is dropping. There's a brilliant piece of audience participation, too. We're all asked, after seeing photos of the special day, to vote on which 1994 newlyweds are no longer together. It's an intriguing social experiment, which might have proved more scientifically valid had Keith not felt duty bound to count each raised arm individually. He's a compassionate soul though, reminding the recently bereaved that the death of a partner does not constitute a failed marriage.

But it's Brydon's ease with the audience which makes this such an entertaining hour. The presence of a middle-aged couple in the front row who don't seem to know each others names is a gift to the performer, as is the divorcee who reckons it was the best £58 he'd ever spent. His desperate hug for a punter in a similar situation is both hysterically funny and quite heartbreaking. Divorce after all can be a new beginning, "the beginning of something much worse".

It's a great character performance. Keith remains likeable, an Alan Partridge without a hint of pomposity yet equally simple. Only the closing line hints at the true terrors that haunt his solitary moments. But tonight he came alive. Perhaps he just needed some human company to gee him up all along.

Venue 3, 7.30pm (1hr) to 17 August (0131-226 2428)