How can a film contain so many clues yet remain utterly clueless? The screen adaptation of "The Da Vinci Code" treats the Dan Brown novel with a reverence it does not deserve and from which it does not benefit. It stars Tom Hanks in his first genuinely dull screen performance. He's not always right for his roles, but never has he receded, tensely, into the woodwork like this. The film was directed by Ron Howard in a style to be named later, and the screenplay by Akiva Goldsman can't get three sentences out without resorting to expositional setups such as "Ah, the Grand Gallery ..." or "Opus Dei. What is that?" "A controversial Catholic sect." And before you know it, the movie has died another death trying to explain it all for you.

It's doubtful anyone who went for the book will hit the nearest Victorian fainting couch over the movie, unless it's for a wee nap to shake off a headache brought on by an excess of speculation regarding the Priory of Sion. It's even more unlikely the film will seduce "Da Vinci Code" skeptics or those who, factoring out the theological implications, found Brown's potboiler to be a lumpy thing, a treasure hunt with characters devoid of character.

The movie version is so intent on taking its mystical and religious business seriously, at an overfull 2 1/2 hours, it forgets to be entertaining. And it sets some sort of record for number of endings in a single picture. I counted 666. Wait a minute. Isn't that number some sort of symbol?

Laboring beneath a haircut that might be called "academic Dutch Boy," Hanks portrays the noted Harvard professor of symbology Robert Langdon, who may be smart but not smart enough to realize Harvard doesn't have a professor of symbology. (For some reason this bugs me more than any of the more outre suppositions involving Jesus and Mary M. sitting in a tree, k-i-s-s-i-n-g.)

Late one evening, Louvre curator Jacques Sauniere (Jean-Pierre Marielle) is murdered by a self-flagellating albino monk (Paul Bettany) in the employ of a devious bishop (Alfred Molina). Before he expires, the curator leaves an absurd number of clues regarding his big secret. Summoned to the Louvre, Langdon quickly comes under the suspicion of the dogged inspector Fache (Jean Reno). But Sophie Neveu (Audrey Tautou), noted police cryptologist and gamine, is on hand to get the plot ball rolling, though it doesn't roll so much as rock, unsteadily. Ian McKellen, playing a Holy Grail enthusiast, is also on hand to remind us that English actors tend to be better than American ones at simultaneously enlivening and showing up a second-rate Hollywood thriller.

It didn't have to turn out this way. I had hopes going in, fueled by all the successful mainstream examples of standard-issue fiction ("Jaws") or outright lousy kitsch ("The Bridges of Madison County") turned into far, far superior pictures. Certainly a looser, fleet-footed adaptation of "The Da Vinci Code" could have been managed, one that knew how to race the slow bits - remember how Ken Russell handled all that Paddy Chayefsky blather in "Altered States"? - while dropping its little corrupt-soul-of-Christianity bombshells and doing its job with panache.

But director Howard isn't much of a panache man, and he doesn't have the soul of a thrillermeister. Nor does he evince much talent for violence (there's a fair bit of it, all ham-handedly managed, including a particularly brutal whacking of a nun). Two editors worked on this picture, and it's some of the most arrhythmic editing you've ever seen, with simple conversations hacked into visual ribbons. Can't two actors get a little uninterrupted screen time to talk things over anymore?

Worst, "The Da Vinci Code" goes in for a flash flood's worth of flashbacks, whether to illustrate the brutality of various Christian wars, or to show Langdon falling down a well as a child, or Sophie and her mysterious grandfather. It's like a flashback fire sale. And early on, when one character turns to another and says, "You're in grave danger," you think, well, everyone's in grave danger - of being burned alive by Hans Zimmer's overheated score. It makes Jerry Goldsmith's music for "The Omen" sound chipper.

The French come off best. Tautou, like Hanks, is required to spend much of "The Da Vinci Code" staring at anagrams or running, but she has better hair than her co-star and comes by her grave intensity honestly. The only real feeling in the picture, however, comes from Reno. There's a nice moment when the monomaniacal police chief realizes another character has abused his trust. A flicker of anger mixes with a flicker of pain in Reno's eyes. In a film full of clues, puzzles and plenty full of something else, it takes one actor registering two emotions to offer a momentary dramatic solution.

"The Da Vinci Code"

Directed by Ron Howard; screenplay by Akiva Goldsman; photographed by Salvatore Totino; edited by Dan Hanley and Mike Hill; music by Hans Zimmer; production design by Allan Cameron; produced by Brian Grazer and John Calley. A Columbia Pictures and Imagine Entertainment release; opens Friday, May 19. Running time: 2:28. MPAA rating: PG-13 (disturbing images, violence, some nudity, thematic material, brief drug references and sexual content).

Robert Langdon - Tom Hanks

Sophie Neveu - Audrey Tautou

Sir Leigh Teabing - Ian McKellen

Capt. Bezu Fache - Jean Reno

Silas - Paul Bettany

Bishop Aringarosa - Alfred Molina