In Patrice Leconte's fanciful new film, Gabor (Daniel Auteuil) gets the message early. Just as he thinks he's persuaded Adèle (Vanessa Paradis) not to leap into the Seine, she takes the big plunge anyway. He follows right behind. What's a little cold water between sudden soulmates? This is a couple made for each other, a desperate, foolish, love-mad duo of the sort French films do best.

The elements are in place here too. Leconte, the veteran director of 18 films, has proved himself a master of morbid, obsessive love with Monsieur Hire, his 1989 masterpiece, and the almost-as-good Hairdresser's Husband. He never fails to make a physically luscious movie, and he's outdone himself this time, thanks to Jean-Marie Dreujou's crystalline black-and-white cinematography and an eclectic score of songs by Marianne Faithfull, Brenda Lee, and Benny Goodman. The Leconte films that tend to make it to American art houses, like Ridicule and the two just mentioned, are taut and sardonic, but the director has an extravagantly playful side, too. Here he lets it loose, spinning the camera 360 degrees or zipping from the ceiling to a sugar bowl to capture a fruitfly's POV. Floating on this cloud of whimsy, his actors wisely play it straight. Auteuil is reliably hangdog, and Paradis, with her pixie face and sex-bomb body, is a ripe foil. She's not a good enough actress to convey the reserves of pain the script demands. Then again, you don't have to infer too much; the film opens with a six-minute monologue in which Adèle tells her life story to an unseen room of interlocutors. "Like flypaper picking up the crud left behind," she explains, she always chooses the wrong guy and suffers the consequences.

Until Gabor steps onto that bridge and steers her right. In the woebegone Adèle, he's found the yang to his yin. He's a knife thrower by trade, and she's ready and willing to be his perfect target. Once they dry off, he plays Pygmalion, giving Adèle a fetching new haircut and a Cirque de Soleil-style makeover. Then they take the act on the road, gallivanting from one glamorous Mediterranean city to another, until a fateful gig on a ritzy cruise ship. Gabor travels with so much luggage you wonder whether Zsa Zsa or Eva is a relative. Adèle has her own problems with self-control. She can't help sleeping with any man who crosses her path, or bumps into her on a moving train. Only Gabor is off-limits. He won't go to bed with the girl in his act.

The sexual tension is channeled into the couple's fevered rehearsals. These lovers don't touch, but they're connected telepathically, understanding each other so well that Adèle can direct a misplaced dagger away from her flesh and Gabor can call to her across continents when their act -- and their relationship -- hits a snag. Shrouded in gauze so Gabor can practice "throwing blind," Adèle writhes in ecstatic pleasure as the knives graze her skin before thudding into the wall. You don't need to be a shrink, or even to have seen Leconte's earlier films, to get the point. Trust is everything. Love means never having to say you're bleeding.

These overheated scenes, as Auteuil strokes his blade and Paradis shivers in anticipation, are the film's best. Girl on the Bridge is kind of ridiculous, but so are many of the best screen romances, not to mention the films by Federico Fellini and Max Ophuls to which Leconte pays homage. I'm willing to suspend a boatload of disbelief, to believe in chance and coincidence and a lot of other hooey, if the payoff is there. But this film doesn't deliver on its outlandish promise. It's madcap when it should be magical, crazy when it should turn wild. Leconte's talents are well-honed, Auteuil's knives are gleaming, and Paradis is game. Europe looks beautiful, and the 90 minutes fly by. Around the edges, though, Girl on the Bridge is a little bit dull.