Natasia Demetriou and Ellie White are Mother and Baby

If the Free Fringe has a spirit, Natasia Demetriou and Ellie White may be its living embodiments. Over the course of Mother and Baby, they are exuberant, eloquent, experimental, sardonic, surreal, self-deprecating and sadistic – sometimes simultaneously. Above all though, they are funny. They represent the vast but relatively untapped potential of the Free Fringe so well that it's almost a shame they will likely be charging admission the next time they return to Edinburgh.

As a performance of sketch comedy, Mother and Baby is a defiantly ramshackle affair, frantic and unpolished, a fact that never once detracts from the double act's virtues or lessens a single laugh. If anything, the fact that Demetriou and White seem to be holding the show together with nerves and giggles (not forgetting the efforts of Camille, their twerking tech) only adds to its charm.

The competitive nature of Demetriou and White's partnership acts as a loose but surprisingly fruitful theme: the childishly bitter rivalry between the pair provides them with every excuse for constant escalation, whether in pace, volume, density of jokes or the over-the-top intensity of their performances.

Behind the air of chaos however, it steadily becomes clear just how much thought and fine-tuning has gone into their material: the sketches, though few in number, are tightly packed with fast-paced non sequiturs and hilariously strange phrasing, combined with a manic, daredevil approach to improvisation and excellent chemistry with the crowd.

If Demetriou and White are this good when they're shambolic, then their future should be watched with keen interest.