So perhaps "American Gangster," Ridley Scott's much-anticipated mobster epic, doesn't have a single original idea in its head, with its unshakable shades of "Scarface" and "Serpico" and "Superfly." And maybe it's a half-hour too long -- this time of year, what film with awards ambitions isn't?

But it's exceptionally crafted and superbly acted, with the on-screen combo of Denzel Washington and Russell Crowe unsurprisingly proving impossible to resist, even though it takes about two hours for their paths to cross.

That's one of the more compelling elements of the film, written by veteran Steven Zaillian ("Schindler's List") and based on a New York magazine article by Mark Jacobson. Washington, as real-life heroin kingpin Frank Lucas, and Crowe, as detective Richie Roberts, are on a collision course with one another that's bursting with the gritty period atmosphere of 1970s Harlem.

(Cinematographer Harris Savides, who has provided dreamlike imagery in the Gus Van Sant films "Gerry," "Elephant" and "Last Days," here creates the faded, intimate look of a movie that truly could have been made 35 years ago, adding to its authenticity.)

Washington simply radiates as Frank, returning comfortably to the charismatic bad-guy territory that earned him an Academy Award in "Training Day." And Crowe, who earlier this year was the one playing the stylish villain you love to root for in the remake of "3:10 to Yuma," is just as powerful as the bulldog on the right side of the law. (Crowe's third teaming with Scott, following his Oscar-winning turn in "Gladiator" and the romantic comedy "A Good Year," further demonstrates the extremes of his versatility.)

That their characters' personalities are such complete opposites may be a bit too obvious, as is the fact that they clearly share a rigid moral code. Both men inhabit their roles so fully, though, they make such shortcomings easy to overlook.

After toiling loyally for years as the driver to distinguished gang lord Ellsworth "Bumpy" Johnson, Frank steps in and takes over the neighborhood after the old man's death. A North Carolina native, he is nattily attired and exceedingly polite, even as he shoots a rival in the head on the sidewalk in broad daylight, but he's also given to flashes of rage in the face of impropriety. That personalized sense of right and wrong, coupled with his Southern-boy charm, serve him well as he builds his own unique empire.

Tired of relying on Mafia middle men to help him import the drugs he will eventually sell on the street, he just flies to Thailand and finds a way to bring back the heroin on his own. He then cuts it twice as strong for half the price, names it Blue Magic and earns both a rabid following and the envy of his competition. That includes the corrupt New York cops who are accustomed to taking their slice of the pie, led by a swaggering, perfectly cast Josh Brolin. (Not everyone could wear that mustache and get away with it.)

That he's made himself a millionaire through the destruction of his own people, urban blacks, doesn't seem to faze Frank. He becomes a fixture on the nightlife circuit with his effortless smile. He buys a mansion for his mother (the formidable Ruby Dee), employs his brothers and marries a former Miss Puerto Rico (the luscious Lymari Nadal). But Scott doesn't let him off the hook -- he's unflinching in showing us the squalor, the decay, the death that result from Frank's business acumen.

At the same time, Richie can't seem to do anything right. He finds sacks full of money stashed in the trunk of a car -- clearly another cop's ill-gotten gains -- and turns them in, knowing that doing so will make him a pariah among his peers. He focuses intensely on his job as a narcotics detective and ends up driving away his ex-wife and young son.

But he works relentlessly, hungrily, and this is a trait that will serve him well even before he realizes he's looking for Frank. All he knows at first is that his partner has died of an overdose, and he's curious about the source of the drugs. And he begins asking around about this mysterious community leader in Harlem, this Robin Hood in a fur coat. (Richie's eventual pairing with Frank at the film's conclusion happens so quickly, it almost feels tacked on, and it seems especially jarring given the elaborate buildup that preceded it.)

Reveling in wretched excess is, of course, one of the main points of a film like "American Gangster" -- the clothes, the homes, the naked women cutting up mounds of powder surrounded by stacks of cash -- but so is the down-and-dirty thrill of the hunt. Scott steadily propels both men's stories toward one another until the tantalizing moment when they finally meet. Then all falls silent and still. It's a breathtaking scene but it's also one of the few you're likely to remember in a film that can otherwise be so derivative.

Running time: 157 minutes.

Three stars out of four.