Religious fiction ...

The Da Vinci Code, by Dan Brown (Doubleday, 454 pp., $24.95)

WHEN a novel has stuck around the top of the New York Times bestseller list for half a year, there is something interesting going on. Such a book has set off a pretty loud pealing of the electric chimes at the front door of the culture. In the case of Dan Brown's The Da Vinci Code, what's so special exactly? That depends on what makes conspiracy theories so fascinating.

Brown starts out with the bizarre murder of a curator at the Louvre by an albino assassin sent, it would seem, by the Catholic religious order Opus Dei. From there we're off like a bottle rocket, as a Harvard professor of "religious symbology," Robert Langdon, who happens to be visiting Paris, is called in for a consultation with the police. For the curator, before he succumbed to his wounds, had taken off all his clothes, arranged himself and some of the nearby artwork in a most curious fashion, and daubed a cryptic message in his own blood, mentioning Langdon's name.

I don't have to tell you that a book like this needs a love interest for protagonist Langdon, whom Brown supplies in the person of Sophie Neveu, a beautiful police cryptologist. Pretty soon Langdon is himself a suspect in the murder and he and Sophie are on the run from the French law. As we learn, a mysterious group of unknown individuals is trying to keep uncomfortable historical truths a secret, and the albino assassin is mixed up in it.

The conspiracy theory at the heart of Dan Brown's huge bestseller was not invented by him (it has been kicking around for years), but it's a juicy one and he's made the most of it, creating a story with a very effective cliffhanger at the end of almost every one of his 105 chapters. You are pulled along relentlessly--a feat of narrative art that really does deserve to be called art, no matter what Yale literary critic Harold Bloom said recently in mocking the "immensely inadequate" Stephen King (a similarly gifted writer) when the latter won a lifetime literary prize. If you don't believe writing in this vein merits appreciation, try thinking up a plot like the one in The Da Vinci Code yourself.

Since Brown's novel is a novel, it can more forthrightly take advantage of the tension inherent in unlocking ancient doors that perhaps should never be opened. He's witty, succinct, and smart--though the reader will have to be prepared to encounter the phrase "the sacred feminine" more than once, and if that makes you extremely queasy, you had better leave this book alone.

But the best thing about The Da Vinci Code is that the conspiracy is just an awfully neat one. What makes for an outstanding conspiracy? It doesn't have to be real, as this one is surely not, despite Brown's inclusion of a preface boldly headlined "FACT." One requirement is a complex array of lore. Brown has that: He provides many fascinating historical and quasi-historical tidbits--like the symbolic significance of the figure of a rose, the mathematical phenomenon called the Fibonacci sequence, the ancient Hebrew coding sequence called atbash, and much more, with an emphasis on the cryptic meanings of the paintings and drawings of Leonardo da Vinci, all artfully woven into the plot.

Above all, a worthwhile conspiracy needs to explain something that previously you didn't know needed explaining, something also that links to a truth, or at least a pseudo-truth, of deep significance. Again, pseudo-depth will do fine--we're talking about entertainment, after all. The Da Vinci Code has this.

But this book is certainly not for everyone, for the following reason. In this sort of thriller, there has to be something urgently important at stake should the conspiracy be revealed. What's at stake in The Da Vinci Code is nothing less than traditional Christianity itself. The Holy Grail, we are told, is not a holy cup but rather holy blood, the lineage of Jesus of Nazareth: The founder of Christianity had a daughter, Sarah, by Mary Magdalene. If true, this theory would overturn some of the central beliefs of Christians.

As a believing Jew, I certainly can't be accused of special pleading on behalf of Christian dogma. This should give me credibility when I say that this "Holy Blood" theory--of Jesus having descendants--is too nutty to merit serious consideration; any suggestion that such a fact could have been kept secret for two millennia is absurd. Brown does acknowledge that there is some merit--some truth and beauty--in Christianity; but such merit as he sees is very far from the faith of actual Christian believers. Any Christian who is offended by fiction that directly contradicts his faith should certainly avoid this book.

If I were a Christian, though, I think I would find it a little disturbing that some fellow Christians do in fact view this novel as a threat to their faith. Some Catholic magazines have published detailed refutations of The Da Vinci Code; that they believe this is necessary indicates that many Catholics, and many in the general reading public, are taking this book far more seriously than they ought to. This also suggests that the problems in Catholic religious education are every bit as severe as Catholic conservatives have been alleging for some time now. If the professional educators were doing their job, any believing Catholic past elementary-school age would know that Brown's book is--a total falsehood.

What about the book's influence in the broader culture? Here, I am calmed by the reflection that there's something profoundly religious about conspiracies in the first place, even fictitious ones. Think about this next time you are at the beach in chilly weather. Though the sky is cloudy and a cold wind is up, you'll see people sitting on blankets in the sand just staring out to sea. Why? Because when you look at the ocean you get the intuition that just under the surface resides a vast hidden world of exotic, usually unseen creatures. The realization that there's all that life underneath--in some ways a mirror of our own world on dry land but in others dramatically different--is simply thrilling. It's what keeps people's eyes glued to the ocean even when there is ostensibly nothing going on out there.

This, too, is what makes a conspiracy thrilling, the revelation of concealed complexity all around. Likewise, it's what attracts many of us to thinking about spiritual matters--the gut-level perception, powerful if unproven, of an existence beyond the one of our mundane daily lives. The Da Vinci Code may be silly; but in its fashion, it's also thrilling. If its popularity means people are thinking about invisible realities, that's good news.

Mr. Klinghoffer's new book is T he Discovery of God: Abraham and the Birth of Monotheism(Doubleday).