What's distinguished the Coen brothers from the beginning of their careers as filmmakers is that they fell madly in love with film itself - as art form, as texture, as magic. They make their movies do things no one else even dreams of. I'm not speaking of mechanical effects or high-tech morphing. Their genius - and it is a kind of genius - is that they create people on screen who though they look and talk like human beings are more likely to be inhabitants of a parallel universe, with the occasional moment of jarring incongruity the only sign we get that something alien has crossed our path.

So we get John Goodman as the next-door neighbor to John Turturro in "Barton Fink," taking us from middle-American bland salesman right through to the apocalypse with a capital A, in one sweet move. And we have Frances McDormand boldly carrying her upstream Minnesota Swedish accent through every scene of "Fargo." To say nothing of Prince (yes, that Prince) lying in the snowy field as a murder victim. And Turturro (again) doing the great Latin bowling champion in a throwaway bit of "The Big Lebowski." And the whole of "Miller's Crossing," a crime film that's just enough off-center that it constantly foils our expectations of what a crime film should be.

But in their newest film, "The Man Who Wasn't There," they've entangled themselves in a genre that ultimately defeats them. The genre is noir, and they ring every bell, cover every base, and meet every requirement of the form in their attempt to do it right. The film is set just after World War II, in the sleepy Northern California town of Santa Rosa. Billy Bob Thornton is Ed Crane, a man defeated. He works the second chair in a barber shop owned by his brother-in-law. His wife Doris (Frances McDormand), who works at Nirdlinger's department store, is uncomfortably close to her boss, Big Dave (James Gandolfini).

So one day when fate walks into the barber shop Ed decides to do something for himself: he'll invest $10,000 in a dry-cleaning franchise. The problem is that he hasn't got the money, and here's where the Coens make a mistake that undercuts the whole film. They've set up Ed as a nebbish, without insight or energy, so his plan to get the money seems to have been made up by a smarter person than he. We in the audience can't quite give Ed the credit he needs for us to believe him capable of the crime. And in fact from that moment on, we lose contact with the character the Coens have tried to create; we don't know whether to see him as smart or as lucky. We know he's not smart, and we've been told his whole life is a string of bad luck, so where did he find the wit and presence to pull off his plan? And smart as he now is, he's still dumb enough to play into the hands of a charlatan salesman. It all just doesn't compute.