Redemption at Hogwarts.

Harry Potter and the Half-Blood Prince, by J. K. Rowling (Scholastic, 652 pp., $29.99)

REVIEWING a Harry Potter book is the ultimate superfluous act. No critic can hope to lay a glove on J. K. Rowling's series, which long ago passed into the realm of universal approbation reserved for mothers, flags, and balanced budgets. The only remaining Harry-skeptics--Christian fundamentalists on one hand and literary scholars like Harold Bloom and A. S. Byatt on the other--have been banished beyond the pale of civilized discourse, and everyone else has given in: We all love Harry, and Voldemort take anyone who doesn't.

It's not that the anti-Potter types don't have a certain point. Judged purely on her literary style, the world's bestselling authoress isn't in nearly the same league as the canonical greats of children's literature--the C.S. Lewises and Kenneth Grahames and Frances Hodgson Burnetts. Not that Rowling is untalented, precisely, but her craft gives the impression of having been stunted by success, as if her development as a writer stalled (or her editors began taking long vacations) when the royalties started rolling in.

Sadly, the latest Potter book, Harry Potter and the Half-Blood Prince, suffers from all the usual faults of the series. The protagonist's interior life hasn't moved beyond the realm of cliche: Harry's stomach lurches, his heart sinks, his mind races, and you can tell when he loses his temper because he tends to BELLOW IN CAPITAL LETTERS! (Though less frequently, thank God, than in The Order of the Phoenix, the last Potter installment, which sometimes felt as if it were written on a laptop with a broken Caps Lock key.) Nor has Rowling managed to shed her addiction to adverbs: Nothing can be said, but it must be said grimly, or coldly, or quickly, or slowly, or scornfully, or hastily, or worst of all, succinctly--all of this in the space of just four pages. And of her tedious magical shootouts--all flying spells and ducking wizards and shouts of "come on!" and "look out!"--the less said the better.

Yet for all these weaknesses, the Potter saga succeeds as few fictions do, and proves, in the process, that there's more to writing than felicitous prose or perfect psychological realism. As with James Fenimore Cooper, or H. P. Lovecraft, or any of the host of novelists whose stories linger long after their stylistic blunderings are forgotten, it's in that mysterious more that Harry Potter's success resides: not in the telling, but in the tale.

That the tale succeeds so well, across so many books, can be credited in large part to Rowling's genius for plotting. Though the Potter books are a casserole of genres--a dash of Tom Brown's Schooldays, a helping of Narnia and the Arthurian legends, a serving of Sweet Valley High (the little wizards have grown up fast)--it's the spirit of Agatha Christie, or perhaps even John le Carre, that broods heaviest over Hogwarts. Each volume follows the structure of a suspense novel: Something nefarious is afoot, and Harry & Co. attempt to ferret it out, usually succeeding just in time for summer vacation. And only in the most carefully crafted whodunits and thrillers do you see the kind of intricate narrative webs, thick with plot and counterplot, dropped hints and hidden clues, that Rowling seems to spin with ease.

The success of her spinning is evident in The Half-Blood Prince, which until its shocking conclusion is a surprisingly uneventful book, packed more with information than with action. Voldemort, Harry's nemesis, has returned from the half-dead, gathered his allies, and launched what might be best described as a terrorist campaign against the magical establishment. The contemporary echoes are obvious, as are the political swipes. In previous books, as Voldemort's power grew, Rowling delivered a cutting portrait of a craven bureaucracy unwilling to face up to the threat. But now that her war has begun in earnest she offers thinly veiled jabs at Guantanamo and the Patriot Act, depicting innocent wizards being locked up by a hysterical Ministry of Magic--a poorly timed message, one suspects, in the author's native Britain.

Amid this gathering storm, calm prevails at Hogwarts, and much of the novel is taken up by the efforts of Albus Dumbledore, the school's aging headmaster and Harry's mentor, to unpack the riddles of Voldemort's past and prepare Harry for the confrontation that awaits, inevitably, in the seventh book. This unpacking takes us deep into the Dark Lord's childhood, and the various revelations demonstrate how cleverly and carefully Rowling has constructed her sub-creation. Her wizarding world isn't quite a secondary landscape on the scale of Tolkien's Middle-Earth: Rather, it's a cracked-mirror view of our own world, with more raffish charm than donnish depth. But it's still a marvelously complex place, thick with tangled family trees, buried secrets, parallel pasts, and double agents. It's a place where plotlines that seemed to have been dropped books ago bear unexpected fruit, where tossed-off comments must be scrutinized carefully -and where everything is seen through Harry's teenage eyes, which suggests that readers should always be wary of leaping to conclusions.

But even the most dexterous plot needs characters, and here, too, Rowling excels--not in plumbing the depths of the self, but in dancing nimbly on the surface of personalities, relying on archetype and caricature in ways that call to mind the best of Dickens. Like a Copperfield, Pip, or Twist, Harry is an appealing everyman surrounded by an astonishingly vivid supporting cast; and just as the Heeps, Micawbers, Fagins, and Havishams are often more memorable than Dickens's protagonists, so too is it the old familiars like Dumbledore and Rubeus Hagrid, Draco Malfoy and Severus Snape who keep readers returning, book after book, to the Potter series.

This genius for character and caricature, though, isn't the only quality that Rowling shares with Dickens. There's also her talent for moralizing without polarizing, a rare gift and a necessity for an author with so wide a following. (The conclusion of The Half-Blood Prince, I suspect, will provoke more tears worldwide than the passing of Little Nell.) Dickens played to a wide audience by mixing a liberal zeal for social reform with a conservative ardor for domestic virtue. Rowling, similarly, ditches the traditional fantasy novel's hints of racism and chauvinism in favor of a liberal-minded multiculturalism--the villains lust after the kind of racial purity that an author like Tolkien granted only to his most heroic characters--while keeping the genre's conservative, good-and-evil core intact. Dark is Dark and Light is Light, and though the twain may meet in some conflicted characters--the fascinating figure of Snape, for instance, Voldemort's-lackey-turned-Dumbledore's-man (or is he?)--there's never a sense that they can coexist for long, or that any George Lucas-style "balance" is possible between them.

It's true that Rowling hasn't written a Narnia-style religious allegory. (Though I wonder if even an Aslan cameo--or a seventh book titled Harry Potter and the Passion of the Christ-would mollify her more zealous Christian critics.) But again, as with Dickens, it doesn't take much special pleading to find a strong religious subtext to her story. The Potter books are heavily medieval, for one thing, stuffed with elements and humors and alchemy and Latinate spells, and stuffed as well with Christ-symbols--phoenixes and stags and unicorns, all associated with the forces of light, and arrayed against the serpent-sign of Voldemort and his Death Eater acolytes (whose name suggests a grisly parody of the Eucharist).

Then there's the central role that death plays in the novels, and the contrast drawn between Harry's companions' willingness to lay down their lives--by the end of The Half-Blood Prince, the hero has lost parents, godparents, classmates, and dear friends to the struggle--and Voldemort's all-too-familiar fear of his own mortality. The Dark Lord's name means "flight-from-death" for a reason, and Rowling is unstinting in developing this theme: More than anything, what distinguishes good from evil in the Potter books is whether a character accepts the admonition, Whoever would save his life must lose it.

Which leads to the inevitable question, whose answer awaits us in the seventh book: not whether good will triumph over evil, but at what cost? The Potter saga began with a sacrificial death: Harry's parents giving their lives to save him, and with him the whole world. If Rowling remains true to her theme, it will take another such sacrifice to complete her achievement, and bring this great, dark fairy tale full circle, and to an end.

Mr. Douthat, the author of Privilege: Harvard and the Education of the Ruling Class, is a reporter-researcher at The Atlantic Monthly.