All at sea with Mystic Meg

Boy meets girl. Boy eats girl. In Jeanette Winterson's new novel, however, the villain's appetite fails him and his wife - or what is left of her - runs off with his former mistress, after plastic surgery, for a lesbian happy ending. At one level, this is an issues-novel, but the cannibalism-issue and surgery-issue are only raised in the last pages. And there are only three speaking characters, though a few others appear sketchily by way of recall.

The best feature is the economy with which the triangular relationship - husband, wife, concubine to both - is handled. So even with help from generous designers, the author needs a lot of padding to fill a short book.

Some of it - about 60 pages' worth - is provided by Winterson's familiar obsessions: tarot, lesbian analytics, the burdens of religious upbringing, father-fixation, the beastliness of men. The heroines reminisce tediously about their births and childhoods, like mixed-up novelists in therapy. This is good for maybe 80 pages more. There is a fair amount of straightforward tautology. A small but much-hyped contribution is made by allusions to the "Grand Universal Theory" trailed in the title: one of the lesbians works on antiquarks, but as the author's knowledge of the subject seems to be drawn mainly from The Physics of Immortality, she might as well be an expert on knitting or cookery.

Winterson reads theoretical physics with help from the tarot pack. She is an adept of post-scientific holism. Her efforts bear the same relation to physics as Mystic Meg's to astronomy. If her book were more readable, it would be suitable for serialisation in Good Housekeeping. "`Jove only works on superstrings because it reminds him of spaghetti', said Signora Rosetti": Jeanette Winterson or Jilly Cooper? "The hard-hat, bull-nose building blocks of matter...have to be returned as an infinite web of relationships": Jeanette Winterson or Tony Blair? Not only politicians mix cliches to mask clap-trap.

As always, Winterson shows she can use language deftly; but she is a wordsmith with nothing to say. Some of her strategic devices are clever. There is a genuinely intriguing sub-plot in which one of the characters is pursued by Jews intent on discovering a diamond secreted inside her against Nazi depredations. This helps keep the reader going through the stodgier passages of padding. Shipboard settings of various kinds are used at intervals to create capsule-like frameworks which can heighten drama or suspense. Disappointingly, Winterson's inattention to detail spoils these promising efforts: her ignorance of routine at sea makes ludicrous a crucial storm-tossed sequence on a small boat.

Like the science, the maritime motif becomes a maelstrom for the writer: she is obviously all at sea. The mystery of the diamond is made baffling by confused physiology. The denouement is a drearily extemporised deus ex machina.

There are some admirably amusing dialogues in the flip manner of Delano Ames but they fail to convince because the characters speak in barely distinguishable voices: short sentences, excised main verbs, metaphors tortured into daring compression. All fiction is autobiographical, but it is confusing for the reader if everybody in the book is based on the author. When we hear that one of the heroines is called Alluvia we wonder whether the whole effort is self-satire - a joke on critics disposed to take it seriously.

Jeanette Winterson is her own best critic. In this novel she confides that lesbianism is narcissism - lust for a mirror image. She seems to have lost the ability to stand back from her work, judge it dispassionately and discard the rubbish.

Her career has become a genuine tragedy - failure worked on ability by hubris. She could be a first-rate journalist, a slick stylist who knows a little about a lot. Instead, she has condemned herself to frustration as a novelist, in an art for which her talent seems exhausted.

There must be something, apart from tarot and lesbianism, which she could write about with deep knowledge and understanding. If she sticks to ships and physics, she is doomed to trip up over her own pretensions. Meanwhile, she imitates her characterisation of new physics, "belching at the dinner table of common sense".