Lighthouse-keeping by Jeanette Winterson

Winterson's brilliant beam

Jeanette Winterson publishes a monthly column on her website. In April's edition she confides her nervousness about the publication of Lighthousekeeping . "People take it personally when they don't enjoy one of my books, (or any of them), and somewhere they feel that my failure to please them makes me a BAD PERSON. So, if you end up not liking Lighthousekeeping, please remember that I have my good points too." She lists her good points as only producing one small bag of rubbish each week and planting 68 trees in the last year.

If critics don't enjoy books, authors always think that we're BAD PEOPLE. We probably are, and I haven't planted a tree in my life. But I'm not expecting an irate Winterson to hammer at my door some time soon. There's no need. Because Lighthousekeeping is an entrancing, gleaming crystal of a book, which left me bereft when it was over.

It's structured like an old-fashioned sock knitted in an endless loop on a circular needle. The whole point of Winterson's storytelling is that it doesn't begin or end. "There was an ending - there always is - but the story went on past the ending - it always does." In as much as it lashes itself down at all, the novel is most closely tied to Silver, a girl orphaned at ten and sent as an apprentice to Pew, the blind keeper of the Cape Wrath lighthouse. But tying yourself down is an overrated business, as the novel will tell you. Silver and her mother live in the "sea-flung, rock-bitten" town of Salts, in a house cut into a hill. "At night my mother tucked me into a hammock slung cross-wise against the slope. In the gentle sway of the night, I dreamed of a place where I wouldn't be fighting gravity with my own body weight. My mother and I had to rope us together like a pair of climbers, just to achieve our own front door." When Silver is 10, her mother falls off the cliff face, but undoes the buckle of their connecting harness to save her daughter's life.

Silver is the still centre, but the narrative glides on oiled prose across two hundred years, with frequent visits to the bleak story of Babel Dark, the crushed, cruel and disappointed former Minister of Salts, who has "refused life". Darkness is everywhere in the novel, pierced fleetingly by the humanising power of Pew's stories. "The darkness had to be brushed away or parted before we could sit down. Darkness squatted on the chairs and hung like a curtain across the stairway."

The pulsing beam of the Lighthouse sweeps across the novel, gilding its inventions with a silvery light. There are comic spotlights too when Charles Darwin visits Salts to examine Babel Dark's fossils and Robert Louis Stevenson drops by to research The Strange Case of Dr Jekyll and Mr Hyde. Lighthousekeeping shows Winterson close to her best, spinning fairy stories with the lightest touch, treating us to a virtuoso display of imaginative fiction.

She admits that she still enjoys reading the Bible for its rhythmic language, and at times she seems hypnotised by her own capacity to invent rhythmic but irritatingly predictable aphorisms. "Why was money worth everything when you had none of it, and nothing when you had too much?" But that's a small complaint about a fine book. And it makes no difference whether she's a good or a bad person. I don't particularly care and neither should she. Pew spends this novel teaching Silver how to say the "three most difficult words in the world ... 'I love you.' " Not that difficult, not when it's Lighthousekeeping you're talking to.