She can do magic

Magic is what happens when you pick up this slab of a book one-handed by mistake, sprain your wrist and don't even notice because you're on page 207 of an 800-page book, Jonathan Strange has just entered the narrative, and you know that what you're going to be doing for the next week of your life is reading Susanna Clarke's debut novel.

Jonathan Strange & Mr Norrell is the oddest book to have come this reviewer's way since Mervyn Peake wrote the Gormenghast trilogy. Like Peake's cycle of novels, Clarke's first work of fiction concerns a fantasy world related to but not quite our own, but that obscures its real achievement: it belongs, strictly speaking, to no genre, on the shelf of oddities.

The world of magic the two practitioners of the title belong to is related far more strongly to the old world of faerie than to either the Harry Potter series or Terry Pratchett's Discworld fantasies.

Compared to those fantastic worlds, Susanna Clarke's England is a far darker, more fascinating place, where the deep legends of a vanished age come to life in a country engaged in fighting Napoleon Bonaparte.

Magic, once common in this alternate England, is now all but forgotten: drawing room politics and turtle dinners have taken over from covens and summonings of wizards long dead. The society of magicians in York confines itself to matters of theoretical importance: none of them can do actual magic.

The first real magician in the book is the very eccentric Mr Norrell, who responds to a challenge set by the York group. His easy victory over them propels him into fame in London, where he strikes a dark bargain with a very unpleasant fairy.

Clarke's fairies, like Clarke's magicians, are not the sweet prototypes you meet in Disney fables; they are possessors of great and inhuman power who do not share normal human values.

In order to set his feet securely on the ladder of fame, Norrell raises up the fiancee of a minister in government from her grave""but at a cost that will become slowly apparent to the lady and to her friends.

This opening section is the hurdle at which many readers might fall: Norrell is neither prepossessing nor interesting, despite his unusual profession.

To leave the first two hundred pages of the story in his hands, while attempting to set the scene for the strangeness (and familiarity) of this alternate England, is a brave and perhaps necessary decision, but it's hard going even for the determined reader.

It isn't until Jonathan Strange, the only other practising magician in all of England, enters the narrative that Clarke's saga really gets off the mark.

The rivalry between Strange and Norrell is rendered all the more intense because they begin as master and apprentice, with Norrell is torn between the deep-seated need to pass on his knowledge, and the fear that his pupil might overtake him.

Strange does precisely this when he's drafted into assisting Wellington in his campaign against Napoleon, and is forced to discover magical powers and spells on his own. Aware now of his own power, and aware too that Norrell has withheld knowledge from him, the acolyte turns against his teacher.

In a brilliant device, Clarke manages to remind us of the legend of the Raven King and the persistence of old magic through a clever use of footnotes. These could be a book in themselves: they run to two lines or two pages, include ballads, legends, extracts from imaginary books, and sly comments on social mores.

"Book-murder was a late addition to English law," runs a typical footnote, "The wilful destruction of a book of magic merited the same punishment as the murder of a Christian." It's an intelligent way to make Clarke's world more plausible, without labouring the point.

The myth of the Raven King is one of the oldest myths emanating from England, and Clarke uses it as a strong plot point, through the device of a prophecy that predicts the return of the king and the emergence of two magicians, clearly Strange and Norrell.

Norrell's hatred of the King is passionate, but curious: his house is built with "stones quarried upon the King's instruction", on land that the King "once owned and knew well".

Strange's fascination with the Raven King""who ruled over three domains, one in England, one in Faerie and one which was reputed to be on the far side of Hell, leased from Lucifer himself""is of a different order.

As magic begins to return to England, sometimes through dubious schools of magic and through magical shops that sound strikingly like our modern-day feng shui boutiques, Strange has his own problems to deal with.

The sinister "gentleman with the thistle-down hair", a fairy with a taste for cutting Faustian deals, has power over the people Strange loves the most.

As the action shifts from battlefield to library to the moors, from Venice to London to Faerie, Strange and Norrell will be forced to decide whether they are puppets of the prophecy or whether they can escape the many traps that lie in wait on the path to the old magical worlds of yore.

To tell this strange, fascinating tale, Clarke employs a style that leans on dry, sardonic observation, shifting occasionally into winding, Dickensian descriptions and sentences.

No one told her before she started writing that there were certain rules: you do not blend social satire with dark whimsy and darker fantasy, you do not write a novel about magic that inserts dry comments about contemporary concerns such as class struggle, you do not hope to introduce Byron in a cameo role and make him work perfectly as a minor character. No one told her, so she went ahead and did it.

This is the oddest work you will read this year; it comes, to use one of her phrases, from "behind the sky", from "the other side of the rain". With the scale of Clarke's ambition, this is not an easy read""hard to digest in parts, rich with plots and sub-plots, rambling, sprawling, demanding.

But as one of her footnotes says, the dictionary meaning of "thaumatomane" is "a person possessed of a passion for magic and wonders". Clarke is one, and if you care to go through the looking glass with her, by the time you reach page 784, you will be a thaumatomane, too.

Jonathan Strange & Mr Norrell

Susanna Clarke
Bloomsbury, distributed by Penguin India
Price: £8.99
Pages: 784