London:

She’s done it again. Defying the nay-sayers, JK Rowling has brought her series to a resoundingly satisfying conclusion with the words: ‘All was well.’

The plotline of The Deathly Hallows (aka the Deadly Shallows) faithfully follows the old engineering adage ‘if it ain’t broke, don’t fix it.’

Like the Isambard Kingdom Brunel of contemporary fiction, Rowling delivers another massive (608 pp) suspension of disbelief with practiced efficiency — on time and on budget.

There is, as before, no shortage of incident or conflict. Breaking with convention, Voldemort shows up on page one. Snape has become headmaster. Harry’s quest for the missing Horcruxes (magical talismen in which Voldemort has secreted parts of his soul) drives a novel that often reads more like an overblown film treatment to a shattering and unputdownable climax in — where else? — Hogwarts school.

If there are tears to be shed, you will have shed them by the end of this compulsive juvenile phenomenon. You will also have renewed acquaintance with a deeper, more troubled Harry, a boy who is near the end of adolescence.

Like any teenager, he is beginning to realise that his future lies behind him. Rowling must know that, too. The Deathly Hallows is not only well plotted, it is also an intricately woven tying up of loose ends with valedictory clarifications of obscure allusions. So what to make of it, now that it’s done?

From the point of view of the English canon, it’s hardly great literature. But if Rowling is neither CS Lewis nor Tolkien, nor Philip Pullman, hers has been, nonetheless, an extraordinary performance. At the end of a decade of accumulating Pottermania, you have to acknowledge, first, the ambition to undertake such a marathon, then the dedication to execute it, and finally the ability to bring it off.

To write one successful children’s book requires uncommon gifts, to write two suggests a touch of magic, but to complete no fewer than seven bestsellers and apparently retain your sanity, and your all-round niceness, is a marvellous achievement. The completion of this world-shaking heptalogy is something close to a triumph.

So what does it all amount to? It’s not difficult to find things in these books to sneer at. Cardboard characters? Tick. Torpid paragraphs? You bet. Flat-footed dialogue? On every page. A more-than-slightly autistic attention to minutiae? No doubt.

Perhaps it’s the autism that animates it. The fair-minded critic has to concede that Rowling’s devilry lies in her attention to detail. The magic of Potter is that he inhabits a fully realised parallel world. Moreover, Rowling does that unbeatable thing: she makes it work.

How exactly she does it remains the mystery, but it’s to do with a primitive grasp of basic

storytelling.

(McCrum is literary editor of the London-based Observer newspaper)