Oh, those wacky French. They will be French, no matter what.

Here's a perfect case in point. The mysterious "On Guard," which sneaks into Visions Cinema today, has all the hallmarks of a murky little art thing, about existential lovers who can't get a good cup of absinthe in the back alleys of Montmartre and so commit suicide by quitting smoking. And what are the hallmarks? It's old (1997), it's unknown, it's unsupported by a big releasing company, and it's not promoted by a marketing campaign.

But guess what: It's about as arty and small as "Cyrano de Bergerac" and twice the fun!

It is, in other words, a big movie: huge sets, giant budget by French standards ($30 million, and remember, they don't have to build any castles!), fabulous costumes and sword fights, a whirling melodrama of a plot, great sword fights, great acting, fabulous sword fights and, of course, really cool sword fights.

So why wasn't it picked up and given more of a ride by some big smart outfit? Why is it so late in getting here? Well, it's because it's so damned French! Hmmm, how can I say this? In the end, it argues persuasively that "La Marseillaise" should be replaced as national anthem by "Thank Heaven for Little Girls." Let's put it another way: This will certainly be Woody Allen's favorite movie.

I'm shocked, shocked that such a thing could be considered possible. But that's what makes the French so French. Anyhow, the movie, called "Le Bossu" ("The Hunchback") in France when it was released in 1997, features the great Daniel Auteuil as a swordsman, acrobat, secret agent and all-around cleverboots named Lagardere. He's part Cyrano (the nose, n'est-ce pas?), part Scaramouche (the laugh, the sense that the world is mad) and part D'Artagnan (the quick sword, but then the other two had quick swords as well).

As the movie opens, in a scuzzy yet beautiful 18th-century Paris, he's begging the fabulous Duke of Nevers (Vincent Perez) for a duel so he can learn the duke's "system," which makes the fellow undefeatable in the repartee of the rapier. The duke humors him, then humiliates him, but likes him. Ultimately they bond, when Lagardere intercepts a letter that a third party meant to destroy and delivers it to the duke. What neither of them knows is that the duke -- insouciant, elegant, casually rich -- is the object of a bitter conspiracy waged by that third party, his nasty low-born cousin Gonzague (Fabrice Luchini). The jealous Gonzague means to inherit the duke's fortune and is willing to kill him if he seems about to marry and produce an heir.

But the de-purloined letter brings the duke word that he is already a father, and he hastens off to tie the knot and legitimize the offspring. Gonzague and his men follow but are slow; they attack after the vows, and after much spectacular bladework, only Lagardere and the baby escape. He vows to return her to her rank in society, and the second half of the movie -- set 16 years later -- is filled with that campaign, which involves Lagardere disguising himself as a hunchback, becoming Gonzague's secretary and engineering a financial coup that will accompany the more usual coup by edged weapon, exactly when Gonzague is about to be invested in a fortune by the king's regent.

This is, not to put too fine a point on it, a swashbuckler, a costume drama. If you love that old story form, you will be in old-fogy heaven, as it is nearly a perfect example of a genre that died out years ago. The director is the great Philippe de Broca, whose great film was "Cartouche" of 1962. And it could be said that just as "Cartouche" was the best film of its year, so is "On Guard" the best film of its year. Unfortunately for its commercial possibilities, that year is still 1962.

On Guard (128 minutes, in French with subtitles at Visions Cinema) is rated PG-13 for violence, including bloody sword piercings in the head.

Marie Gillain and Daniel Auteuil, above, and Vincent Perez in a swashbuckling sleeper from France opening today at Visions Cinema.