Supermarket Supermodel, by Jim Cartwright

A fable in fashion from check-out to catwalk

Jim Cartwright spins thoroughly modern fables. In his best-known play, The Rise and Fall of Little Voice, he sent Jane Horrocks off on Cinderella's tangent from shy mute to showstopper. Now he turns his hand to fiction, but his theme remains the same: Linda Dripping, check-out girl, turns into Crystalline, catwalk queen. A celebrity morality tale, written in fizzing, high-voltage vernacular, it is ultimately inspiring rather than cautionary.

The book divides roughly into three. The first is all gritty Northern realism and cheerful camaraderie among check-out staff at "Safeshop": touches of John Fuller's "Linda, Linda, slender and pretty/ Biscuit girl in a biscuit city". A horoscope predicts change, and that very day (I told you this was a fairy tale) she meets a tall, dark talent-scout and shoots to fame.

Here the gear shifts from Sillitoe to Easton Ellis. Our heroine plumps to call herself Crystalline, and soon she is getting high on yachts and delivering insouciant headbutts ("Blood shot from his nose. He looked in absolute shock [sic]. Then I walked out."). When she arrives in LA, grammar dissolves completely, as is traditional. With Crystalline now in dire need of a fairy godmother, Jackie Collins makes her entrance. Her guest cameo is as camp as panto; a hilarious little interlude.

By now, this Bildungsroman is feeling exhilaratingly out-of-control. The depth of field veers wildly, from macro to micro. Important scenes flash by while others are garlanded with vivid poetics. When Jackie Collins scolds it is "like being hit with a rose".

Cartwright is an intoxicating writer, with a god-given gift for metaphor, but he still reads more like a playwright than a novelist, all ears for language and no eyes. Many sentences hinge awkwardly round a comma. Once or twice, he falls back on long speeches to propel the action, more in the manner of a Greek tragedian than a novelist.

The third part, set after Linda's riches have reverted to rags, is the most original and satisfying section. Cartwright is a mature fabulist, with a real commitment to working out what happens next. You read with wonder and delight as the heroine finally comes into her own and the book does too, reaching a new level of clarity and exuberance as Linda/Crystalline, working under the direction of a dead friend's unfinished self-help manuscript (as you do), starts a modelling agency for homeless people, "Urchins". They undermine the fashion industry from within: "It was like the death of the pose".

It's unbelievable, right? But the fairy-tale teller's job is to make us believe the unbelievable, and here we do – at any rate, until the book ends and the spell breaks. It won't linger in most brains for long, but it might have a life-changing effect on a teen.