The Woman in White, Palace Theatre, London

Lloyd Webber's music and Trevor Nunn's assured and fluent production, with its dizzying whirl of video projections, impart an authentic spookiness to the encounter

You're walking down a deserted moonlit road when suddenly Andrew Lloyd Webber springs out before you, dressed all in white and babbling about "my secret, my precious secret". The sight chills you to the marrow and yet stirs you to compassion. He must mean the secret, which has eluded him lately, of writing a mega-smash hit.

How's that for a viable scenario? In fact (with certain adjustments), Wilkie Collins had the idea first in The Woman in White, the sensationalist Victorian novel that Lloyd Webber has now converted into a £4m musical, with the aid of Charlotte Jones, who did the nifty adaptation, and the American lyricist David Zippel. In this new version, the fateful meeting with the eponymous woman is imaginatively shifted from the London suburbs to a nocturnal Cumberland railway station, where the the hero, Walter Hartwright (Martin Crewes), is stranded.

Lloyd Webber's music and Trevor Nunn's assured and fluent production, with its dizzying whirl of video projections, impart an authentic spookiness to the encounter. Telegraph wires sing with a ghostly and increasingly ominous insistence as the Woman (Angela Christian) emerges from the mist. She proclaims possession of the terrible secret that drives Collins's enormously complicated plot, involving lookalikes, switched bodies and an elaborate, seemingly flawless crime masterminded by Michael Crawford's bloated villain, Count Fosco, a professionally charming Italian with a penchant for bonbons, birds and pet mice.

From the novel's intractable mass of intricacies, Jones has fashioned a more streamlined plot, with some telling additions and pointed ironies. It makes sound emotional sense that the plain, resourceful sister Marian, sung with superb ardour by Maria Friedman, should nurse an unrequited passion for the hero, who loves her beautiful half-sibling Laura (Jill Paice). Indeed, the song "All for Laura", in which Marian guiltily wonders whether she has been self-interested in her protectiveness toward her sister, displays genuine dramatic development as it moves from apprehension to the resolve to be truly strong on someone else's behalf. And the top-secret new ending has a satisfying symmetry.

Lloyd Webber's score is at its best when it captures the spirit of the story's weird Gothic overtones. At Laura's wedding to the caddish Sir Percival (an insipid Oliver Darley), there's a creepily atonal setting of "The Holly and the Ivy", while images of the church reel nauseatingly round. The corny Lammastide rustic routine is reprised with anguished discordance during a drugged dream sequence. But we're a long way from the brilliance of Sondheim's Sweeney Todd. Too many of the songs emit the generic pop-opera sound of Lloyd Webber-land. And for all Crawford's efforts to frisk up Fosco, the plonking lyrics don't have enough comic lift, the cod-Italianate "You Can Get Away with Anything" being the closest to something reasonably funny. A bird got loose during one of these numbers and flapped around, looking for a way out. One can only assume that it had had enough.

That said, Lloyd Webber seems more in his element here than in his last two comparative failures. If The Woman in White doesn't quite put his credibility back in the black, I suspect that it will be haunting the West End for some time to come.

Booking to 5 March (0870 895 5579)