For two hours every evening until 28 April atBristol’s Brewery Theatre, something rather peculiar is happening. A journey onto the astral plane, a glimpse into the world beyond, call it what you will – the Ogden Sisters have come to town, and they’ve brought their Spiritual Telephonic Device. More importantly, they’ve brought an immense sense of fun, and though one would be hard-pushed to call the comedy on display here intelligent, the guileless puns, modest magic tricks and bawdy moments of physical comedy are carried off with harmless, homespun charm.

To give a more comprehensive account of the show would spoil things. But it’s worth acknowledging that Trifle Gathering Productions has unabashedly embraced the kitsch, sometime-derided mode of audience interaction, and audiences would do best to do the same. There is little doubt that my personal experience of the Sisters’ soiree was improved by the wearing of a ginger beard, and some vigorous ritualistic bongo-drumming. Similarly, I doubt the gentleman sat next to me will ever again doubt the existence of the ethereal – let’s just say that these siblings don’t respond kindly to sceptics.

The Sisters themselves, Constant, Adeline and Lettie (Sally Cook, Adrian Mercuri and Kyla Goodey, respectively), marshal the audience’s expedition into the ectoplasmic with a droll mock-seriousness. Perhaps the real mysticism of the piece is how each manages to keep a straight face, whilst engaging directly with audience members who are often too busy laughing to respond. In this department, it is Cook who excels, eliciting giggles simply for fixing unsuspecting patrons with her steely gaze whilst never missing a beat, but all deserve praise – not least Goodey, also the piece’s co-writer, who navigates her rowdy and randy trances with aplomb. Things get decidedly patchy towards the middle, as a few stabs at poignancy and emotional sincerity come off as stale and unnecessary, culminating in a weak and obviously shoehorned-in musical number from Mercuri, but the succession of surreal coups de théâtre which quickly follow put all that out of mind.

Intimate, silly and sensually all-encompassing (don’t ask), A Curious Evening of Trance and Rap with the Ogden Sisters has to be experienced to be understood. Don’t expect anything cerebral. Don’t expect to find the playtext in the National Theatre Bookshop. But throw yourself into the charade and you can expect a very fun evening indeed.