Danny Archer (Leonardo DiCaprio) is an ex-mercenary from Zimbabwe who now makes a living trading guns to the rebel forces in Sierra Leone in exchange for the diamonds they illegally harvest using slave labor circa 1999. One of those laborers is Solomon Vandy (Djimon Hounsou), and after a chance encounter the gruff, cynical soldier-of-fortune learns the man has hidden a rare and extremely valuable pink diamond somewhere deep within non-government territory.

The former Mende fisherman has buried the gem near the mining site at great personal risk before being captured by government forces. He has not done this, however, for personal gain. Instead, he realizes this diamond could spell freedom for his entire family, and the only thing he cares about is being reunited within their loving embrace. He is the father, after all, and Solomon must do whatever he can to protect them. If that means associating himself with the duplicitous Archer in exchange for his assistance in securing their safety than so be it.

Into this combustible mix comes Maddy Bowen (Jennifer Connelly), a driven American journalist doing a story on African conflict diamonds and the multinational conglomerates who purchase them illegally. At first she sees helping these two as only a means to an end, the information they collectively posses enough to give the woman the story of a lifetime. But as this trio descends deeper into the African abyss, the moral complexities of the situation open Maddy’s eyes and move her to actions she never could have anticipated.

Director Ed Zwick’s (“Legends of the Fall”) “Blood Diamond” is a multi-layered, character-driven thriller pulsing with life. In the end, this movie isn’t so much the story of a lost soul reacquiring his humanity thanks a driven fisherman as it is the tale of a father willing to do whatever it takes to win back the heart and mind of the beloved son repulsively stolen from him. It is a brutal, highly-charged motion picture where the tension energizing the situation is profoundly visceral, the complexity of these three protagonists bringing an emotional resonance you don’t normally find in a film with so many bullets and car chases.

Ironically, it is within those action sequences that Zwick seems to falter this time. Not that they are bad. Just the opposite, the man behind “Glory” and “Courage Under Fire” no stranger to battlefield theatrics. Unfortunately, it is the filmmaker’s corny melodramatic tendencies within those sequences that almost does him in. Like “The Last Samurai,” the director loves to shoot thousands upon thousands of bullets at his heroes only to have every single one of them miss the mark by a wide margin.

He adores seeing them jump and roll and leap out of the way, diving just at the right moment to swerve out of the path of helicopter machine guns and legions of soldiers who just happen to have them boxed in. Meanwhile, Archer can’t miss, and this Rambo mentality is silly and absurd enough to almost undermine what is overall an exciting and electric motion picture.

Somehow it doesn’t. The inherent drama delivered by Charles Leavitt’s (“K-Pax,” of which now I will probably have to partly forgive him for) is palpable, and as acted by the three leads impossible to ignore. A person cannot help but be moved and horrified by the sight of young pre-teen children being transformed systematically into inhuman monsters. Even when Zwick’s liberal-leaning sermonizing almost gets the better of him somehow he always manages to pull things back together, “Blood Diamond” getting under my skin so thoroughly I was almost sad to see it finally come to an end.

Without question, 2006 has turned into the year of Leonardo DiCaprio. He was the galvanizing force driving Martin Scoresese’s “The Departed” and he’s even more impressive here. Don’t be fooled by the trailers. DiCaprio nails the South African accent to perfection, disappearing so completely inside the character I utterly forgot at a certain point it was the former “Titanic” heartthrob up there on the screen. He is magnificent, and the only question now is to as which film Oscar voters are going to ultimately decide to recognize him for as a Best Actor nominee.

What would – and probably will – be a crime is if Hounsou doesn’t join him at the Kodak Theater as a Best Supporting Actor nominee. He is this picture’s center, its unadulterated heart and soul. As good as the other two are “Blood Diamond” would be nothing without his impassioned presence. Because of him every ounce of this story’s emotional power slapped me across the face like a frozen hand in the middle of winter. The man is ferocious, the movie worth the price of admission just to see his face as it takes in the maddening terror of what the rebels have attempted to turn his beloved son into.

Still, it goes without saying this is still far from the best work Zwick has ever accomplished. A couple of scenes between Archer and Bowen reek of didactic platitudes, while the coincidences inherent in Leavitt’s script are a bit too farfetched even for me. Some incredibly fine character actors (most notably “The Queen” star Michael Sheen) are wasted in throwaway parts, while the usually reliable James Newton Howard (“Lady in the Water”) contributes a score far below his normally high standards.

Yet I do admit to liking this movie. It is an acting triumph for the leads, and while Zwick’s penchant for sentimentality gets in the way a time or two his skills as a storyteller bail him out over and over again. Like the gems it revolves around, this film is a bit rough around the edges and at times difficult to see the beauty in. But scrape away the grime and look past some of the sharp corners and “Blood Diamond” doesn’t just shine, it sparkles.

Film Rating: êêê  (out of 4)