The Pajama Men: The Last Stand To Reason, Assembly Rooms, Edinburgh

The Last Stand to Reason eclipses last year's Versus vs Versus by virtue of its pace and comparative accessibility. Dressed in their titular nightwear, the two thirtysomethings serve up a stream of quirky characters aboard the same train, bound for nowhere in particular – from a mass-murderer to as impossibly cute and unspecified "small thing". There is a menagerie of misfits in between, brought to life by some superbly dextrous vocal and physical morphing – including a pair of spinsters talking ten to the dozen, and a couple of lecherous old men who give a running commentary on the women that walk by: "That ass is so round King Arthur probably sits at that ass."

Skits flow thick and fast: Russian roulette is played by two characters as if they were merely smoking cigarettes; elsewhere a schlocky magician shuffles cards for a circumspect punter in implausible fashions. This delightful tomfoolery is assisted by some generous ad-libbing that shows that this team can count warmth as well as efficiency among their qualities. It's a harmony nicely summed up by the exchange "We know each other so well we finish each others' ..." "Sandwiches?"

Such impeccable comic timing and reflexes make this show a joy to watch. The pair have offered the festival punter a recognisable brand for narrative-based comedy away from the usual sketch, stand up and character variety. The Pajamas can divide a room, however, and the pitch to which their comedy works up proves too much for a few people, some of whom leave early. This in itself provides an opportunity for Chavez and Allen to prove that audience interaction is another area they have improved in.

Ultimately, it matters little that the narrative tie is not as strong as the individual characterisations. It's fair to say that to get the most out of the show you have to be open to the charms of the performers. If they catch you in the right mood, however, the Pajamas are a party that won't put you to sleep.

Pajama Men are at Soho Theatre, London, 7 December to 9 January (020-7478 0100)