Into the Woods, Open Air Theatre, Regent's Park, London

Into the Woods goes virtually site-specific with this sharp, spirited revival of Sondheim's 1987 musical. Offering a Freudian take on fairy tales as psychological rites-of-passage, the piece is inventively directed by Timothy Sheader and Liam Steel in the sylvan setting of Regent Park's Open Air Theatre.

Thanks to Soutra Gilmour's ingenious design, there is no danger, though, that we will fail to see the metaphorical wood for the actual trees. Beautifully integrated into the bosky backdrop there's a maze-like set of multi-level platforms, walkways and curling staircases. Stealing forth from the eerily lit trees, the excellent cast take command of a structure that skilfully accommodates the several, farcically criss-crossing, narratives, while conjuring a sense of the subconscious forest of the mind.

Mark Hadfield and the splendid Jenna Russell bring a touchingly humorous humanity to the role of the Baker and his Wife who, in order to lift the curse of childlessness, are enjoined to procure Little Red Riding Hood's cape, Cinderella's slipper, Jack's cow, and a swatch of Rapunzel's hair. This quest involves the couple sneaking into Grimm storylines and screwing them up.

There's some expertly droll playing here, especially from Michael Xavier who doubles as a cockily louche Wolf and a snootily self-absorbed Prince Charming. And the production keeps up a steady stream of enchanting visual wit: voiced by Judi Dench, the vengeful puppet Giantess is evoked through an unstable mosaic of objects including huge electric-fan eyes.

The main innovation is to make the narrator-figure a 12-year-old boy whose odd personal relationship to the story is eventually revealed. The device works movingly on some levels – it gives an optimistic twist to the theme of flawed parenting embodied by Hannah Waddingham's balefully possessive Witch, but it creates incoherence elsewhere, and can't distract you from the show's fundamental defect.

The second act subsides into a succession of increasingly explicit sermons on the need to put collective responsibility before individual wishes. Interspersed with unconvincing uplift, it comes across less as a genuine development of the shapelier, foregoing material than as a laboriously protracted postscript.

To 11 September (020 7907 7071)