For almost thirty years, beginning when he was a young protegé of Robert Altman, director Alan Rudolph has made his career by showing us the difficult, often failing relationships of the characters in his films. "Welcome to L.A.," "Remember My Name," "Choose Me," "The Moderns" and "Mrs. Parker and the Vicious Circle" all show his predilection for worming his camera in and out of the tormented people we see on the screen. He is the most literary of contemporary directors, as interested in the inner lives of his people as in whatever might pass for a plot, or even a believable event, which makes it harder to be a fan of his work than it would be to go through the agonies of his characters.

His new film, "The Secret Lives of Dentists," comes from an early Jane Smiley novella called, appropriately, "The Age of Grief." Adapted by screenwriter Craig Lucas, the film is the story of the seemingly happy marriage of David and Dana Hurst (Campbell Scott and Hope Davis), who share a dental practice and have three little girls at home. But early on, David has two shocking moments: first, he sees Dana apparently in the arms of another man; and then Slater, an obnoxious patient (Denis Leary), insults his dental work in front of a theatre audience.

At home, he works hard at being the nurturing parent (his littlest daughter screams for him, he prepares the meals, he comforts the girls); Dana is somehow able to separate herself from the mechanics of running the household. Their marriage, which started with wild romance and sex (we see flashbacks) has become stilted and formalized; David and Dana are more housemates than lovers. And as his suspicions of Dana's secret affair grow, he somehow imports Slater to be his fantasy doppelgänger, a macho figure who urges David toward mayhem and confrontation. So the triangle of David, Dana and her unknown lover now adds a second, overlapping one: David, Dana and Slater. At the same time, the film shows us those moments that make a family believable; mealtimes, tantrums and the kind of episode that all families go through: everyone comes down with a stomach virus.

But the possibility of Dana's affair eats at everything David does; he cannot talk to her without wanting to scream, but still he cannot bring it up. Nor does she. So it sits like a weight on everyone in the film, while we in the audience wait to see a denouement. And this is where the film fails for me. What can work in a novella, where implications and glancing blows suffice to trigger a reader's response, does not work so well in a film that occupies a theatre screen filled with fully visible characters who present themselves already fleshed out. The film has an ending, but it is not a satisfactory one. Moreover, the very visibility of Slater becomes annoying and repetitious long before the end; to make him so real, and so monotonous, is a sad mistake in the film. Leary has done much better work elsewhere.