What is a critic to do when everything about a film is exciting, involving and emotional, and manages to convey both the depravity and the exaltations of life, except that the actor playing the leading character is wrongly cast, inept, clumsy and heavy-handed when he should be perceptive, observant and aware of his situation? Yes, that's a rhetorical question, but it almost destroys one of the best films of this year, "The Children of Huang Shi."

Before I get to the actor, let me say that the story itself is astounding - based on the true tale of a British journalist, George Hogg, who came to China in 1938, bluffed his way into Nanjing and photographed the Japanese rape and murder of its inhabitants, was caught but then was rescued by a Communist guerrilla group and spirited away to a refuge in a little makeshift orphanage for boys - and then, and this is the most amazing thing: when the Japanese and the Nationalists (who wanted the boys as soldiers) came too close, he then led the children on a 1,000-kilometer march - the 'little long march,' as someone in the film describes it, to safety in the far northwest - at the edge of the Gobi desert, along the old Silk Route.

And it doesn't hurt that his medical companion and lover is Radha Mitchell, whom surely I would follow anywhere, and his military expert and savior is Chow Yun-Fat, whom anyone would want on their side in even the worst kind of conflict.

But now I must turn to our lead, the British actor Jonathan Rhys Meyers, who was, yes, perfectly cast in Woody Allen's "Match Point," but who is woefully wrong here in "The Children of Huang Shi." In a film that contains every kind of misfortune, where it is obvious that only the most desperate kind of cooperation will keep evil at bay, where death itself is not necessarily the worst outcome, Mr. Rhys Meyers poses rather than responds; he seems to be in a film of his own choosing rather than a participant in the most devastating kind of struggle. And director Roger Spottiswoode is not without blame; he photographs Rhys Meyers as though he were a living icon instead of a man who finds courage for the first time in his life.

And yet the story of "The Children of Huang Shi" is so moving, the children of the film are so natural, the work of Mitchell, Chow Yun-Fat and Michelle Yeoh ("Crouching Tiger, Hidden Dragon") as a merchant and supplier of opium to those who need it, is so magnetic, that the film survives its miscasting of the lead. Get past the work of its main character (and you will) and you will see a film that has greatness in it.