Jim Jarmusch has always gone his own way, using his films to focus our attention on the detritus of life that we'd otherwise walk past without a thought except to keep our shoes from being caught in it. But in "Ghost Dog" he has made a film that takes a very sideways look at morality, at culture clashes, and at the art form of film itself, and he's come out with what may be his best work to date. It's a film that treats murder in the way a samurai would treat it, and expects us to understand and support it. Which we do, because watching it happen is delicious.

Ghost Dog is the name of a black hit man (Forest Whitaker), who lives by the rules of the samurai. Years before, his life was saved by a member of the mob, and ever since he has tied his own life to that of his savior, Louie (John Tormey), dedicating himself to Louie's service. He sends carrier pigeons to Louie, who returns them with messages about who he should kill. Ghost Dog, who lives a hermit's existence, doesn't get paid by the job, but insists on an annual fee to be paid on the first day of autumn each year. When he has questions about his day, or his job, or his life, he turns to the Book of the Samurai, which he reads aloud as the words are printed on the screen.

Ghost Dog has one friend, a Haitian ice-cream truck vendor who speaks no English, while Ghost Dog speaks no French; yet in another of Jarmusch's unlikely connections they understand each other quite well. The film's plot, such as it is, begins with Ghost Dog's hit on a mob traitor, who unfortunately has with him the daughter of the mob's boss, so the boss orders the removal of Ghost Dog himself. But more important than any plot is the way Jarmusch gives us his people. The daughter, supposedly insane, spends her time watching television cartoons, but so does almost everyone else in the film. The mob hangs out in the back of a Chinese restaurant but can't even meet its rent bill there.

"Ghost Dog's" music is by the RZA, who founded the Wu-Tang Clan, and it is astounding in the way it reflects not just action or event but sets the emotional temperature of every part of the film. The cinematographer is the great Robby Muller, who shot "Paris Texas," "Repo Man," and a number of Wim Wenders's films as well as most of Jarmusch's. Muller's genius is in how he uses light and darkness, whether natural or artificial, and here his work is just breathtaking without being in any way intrusive. The many night street scenes are given to us exactly as our own eyes would record them -- almost an impossibility for motion pictures to duplicate because movie lamp bulbs can't provide the visibility that our eyes can respond to. Movie lights are too intense close up, too dim far away -- something that our brains compensate for in real life.

The film does have a few longeurs in the middle, when Jarmusch seems to have lost his timing and everything slows down, but he soon picks things up again and treats us to a true samurai ending.