Bat for Lashes, Koko, London

No need to dial 999 – she's OK. If Natasha Khan, aka Bat for Lashes, was robbed when she didn't win this year's Mercury Music Prize, larceny hasn't stilled her progress. The two sold-out gigs at Koko prove that the ex-nursery-school teacher's debut, Fur and Gold, is casting a pixie-pop spell over her fanbase, which includes Thom Yorke and Björk.

Bat's spectral mix of textured chamber-pop and avant-folk aims to conjure an atmosphere: on top of masks distributed at the entrance, the stage is a tree-decked, glittery winter wonderland, part-dreamscape, part-psychosexual grotto and part-appeal to the Jungian-at-heart childhood imagination's access to the universal consciousness (well, that sort of thing). It's a good fit for Bat's mantra-like incantations.

Her band has grown for the occasion, too. A string section bows and scrapes behind Khan, whose flowing black robes approximate queen-of-Hallowe'en chic. She proudly displays a new instrument of her own: an imperious, spirit-summoning "wizard stick", used to wallop the stage, Gandalf-style, on "Sarah".

That said, tonight the music doesn't always project, astrally or otherwise. A reticent sound mix and a certain politeness curtail some of the hinted-at emotional magic, leaving you feeling distanced rather than swept up with the visceral flurries of imagination.

The tingles are summoned, albeit in flashes. Khan makes a stripped-back entrance, her crooning backed only by fairy bells (or something like that), before a flick-knife bass and a death's-head piano summon up the totemic rumble of "Trophy", a trance-like tale of pagan portent and dark desire. Later, "I Saw a Light" channels rare, raw passions, Khan crying "Death in your arms" with a throaty roar.

Bat's songs either verge on the point of departure or tease at just-out-of-reach currents: a "bat-lightning heart" wants to fly on the spectral Spector-pop of "What's a Girl to Do"; "Sad Eyes" hints at desires that can't be fulfilled without self-destructing, and a cover of Tom Waits's "Lonely" transforms the original's gruff vulnerability into something hypnotic and intangible.

"Horse and I" is the set's centrepiece, playing like a signature tune as its invokes a dream journey into the unknown, swathed in heart-fluttering harpsichord. Who needs a Mercury when you've got a "mystic golden light" and a magic horse to lead the way? If tonight was a hint at what's to come, rather than the full trip in itself, it's still clear that Khan is going places, spreading just enough fairy dust to light the way.