In case you've missed the story thus far, here's a recap. A year ago, the Guardian gave the writer Will Hodgkinson £5,000 to set up his own record label. He duly signed Thistletown, a Cornish folk quartet of decidedly hippy bent. Over the following months, he booked gigs, helped them record an album, argued with them about ducks and then, money spent and journalistic project completed, said goodbye.

Where does this leave Thistletown? That album, Rosemarie, released last week, has had some positive reviews - but cynicism demands that one suspects those reviewers to be pals of Hodgkinson. From what he has written, the band themselves are fairly cynical about their prospects. This gig could be the last London sees of them.

It shouldn't be, because Thistletown - in a rough, unformed fashion - are fascinating. There is much they need to learn about songwriting and stagecraft. Their lyrics are terrible: self-consciously poetic, mystical nonsense about dancing around trees, dancing beneath stormy skies, dancing (you'll notice a theme here) as nightingales sing. Their six-song set lasts an hour because the band - expanded to an octet, including Michael Tyack of the medieval folk-rock band Circulus - spend interminable minutes faffing about between each one.

But these irritations are forgivable because when the music starts, it is mesmerising. Glow Worm drones with the eerie force of a pagan ritual; with every keening note, Dance With the Sea grows more powerful. Under the Trees is profoundly strange, a kind of Elizabethan square dance set within a classical Indian raga. Underpinning everything is the lithe bass-playing of Al Davies, who could be performing with the post-rock band Tortoise. It's an odd but enticing mix, promising enough to make you hope Thistletown survive.