Australian comedian Zoe Coombs Marr first brought her oafish alter ego Dave to last year's Fringe. Created in response to poor comedy in general and misogynistic stand-up in particular, Dave is a vulgar concoction who spews offensive jokes at his audience. It's very clear from the off that he's an over-the-top character portrayed by a woman in drag, although Coombs Marr claims she's previously suffered walk-outs from audience members taken in by the act.

In Trigger Warning, Dave starts with his offensive shtick as usual before suddenly claiming that, following a tête-à-tête on Twitter with a group of 'feminazis', he's decided to put that sort of behaviour behind him, claiming he's now a changed man. This about-turn is the first of several surprising twists as Trigger Warning starts to unravel in interesting and unexpected directions. Dave renounces stand-up comedy and tries his hand at mime, claiming to have recently studied at the Gaulier clown school. And at various points he turns into Zoe, a thirtysomething lesbian comedian.

As Dave (or is it Zoe?) further folds in on himself, the show turns into a fascinating deconstruction of ego before the comedian makes explicit reference to Christopher Nolan's mind-bending dreams-within-dreams film Inception. Coombs Marr's postmodern matryoshka doll of a show is spellbinding and intricately crafted. The opening act as Dave is a genuinely funny piece of character comedy and the initial rug-pull feels incongruous before the pieces gradually fall into place.

Not everyone will get the joke and from the outset, elaborate call-backs are set up which, in the context of Dave's bad stand-up act, appear to be throwaway gags. Coombs Marr has done the unexpected with her odious creation and through a committed performance she makes him part of something very special indeed.

Underbelly Cowgate, until 28 Aug (not 15), 6.50pm, £10–£11 (£9–£10).