IN THE REALM of acting, subtlety and bravery don't often come together. The actors most willing to risk themselves usually have the greatest desire to beat the audience into submission. Christian Bale stands out from the pack. It must have been Bale's air of confidentiality that got him the role of the Bat. And in Werner Herzog's startlingly positive—and often surprisingly funny—ordeal story, Rescue Dawn, Bale insists that heroism is a function of a bottomless simplicity; it's not a larger-than-life attitude one carries around everywhere.

Herzog's old grudge against the evil of jungles appears the same here as it did in his interviews in Les Blank's documentary Burden of Dreams. The nerve-tightening monotony of the greenery closes in on the prisoners, up until the final excruciatingly suspenseful moment of the jail break.

Rescue Dawn's curiosity toward the subject of heroism makes this different from the ordinary green-hell film, even though there are some of the usual details: the leeches, the barking guards, the fevers, the meal of snake-meat and insects.

A fine line separates ingenuity and imaginativeness; it's the space between being a man who sees a clear route through obstacles and a man who foresees the obstacles and dreads the consequences of hitting them. Bale plays Navy pilot Dieter Dengler as an ingenious man. His weird optimism—baffling to the human skeletons imprisoned with him in a Laotian prison camp—is the real mystery in Rescue Dawn.

Dengler was a U.S. Navy pilot assigned to the secret air raids against Laos early in the Vietnam War. During the mission briefing aboard the aircraft carrier, his buddy Spook (Toby Huss) sasses the instructional film about how they pilots can survive in the jungle if they crash. In his few scenes, this accomplished comic actor manages to capture something of the bored, compulsive joker doing his time in the military; there's something abrasive in the way he horses around.

After a short flight, Dengler arrives at his target. His wing is ripped by anti-aircraft fire, and crashes in the jungle. The peasants who find him mistreat him; they stake him in the sun and tie a hive of ants to his face.

Finally, he arrives in the small compound where the Communist Pathet Lao guerrillas keep their prisoners, a mixed band of a half-dozen Asian and American soldiers.

The Pathet Lao feed the prisoners small rations and keep them pilloried at night, laid head to feet in wooden braces. Eugene (Jeremy Davies) from Eugene, Ore., makes the biggest impression; he's delusional, half-wrecked by starvation. Davies gives us a unique turn on a familiar figure from 1970s films: the male Cassandra, full of psychedelic horror, like Dennis Hopper in Apocalypse Now.

Steve Zahn's furry-faced Duane is more understated; usually the craziest man in the movie, Zahn gets a chance to be laid-back and endearing. He listens to Dengler's seemingly mad ideas to escape. With a stolen nail, a shard of mirror and endless patience, Dengler and his fellow prisoners finally make a break for it into the jungle.

As the soldiers split up after the escape, Duane accompanies Dengler for the rest of the two-man journey. Duane gets closest to the enigma of the heroic Dengler, when listening to his story of World War II. Dengler grew up in Bavaria, and his home was dive-bombed by the Allies; when the pilot waved at him, Dengler felt as if it were a kind of blessing. "After that, little Dieter needed to fly," Dengler says. Little Dieter Needs to Fly was the title of Herzog's 1997 documentary on Dengler. The enigma of a man becoming a pilot because his house was bombed must have drawn Herzog to this story.

Herzog takes a documentary maker's approach to storytelling, and Rescue Dawn has the unadorned, rough-hewn quality of a soldier's anecdote. But there are flat patches. Note the interrogation scene in which a commissar doesn't even stop to record Dengler's name, rank or serial number (he seems to be there merely to demonstrate that there were decent soldiers on the Communist side of the line).

The celebration at the end is a mob scene with no intimacy to it. By contrast, the scene of the scarecrow prisoners, so deep in the mud and shit they barely notice it anymore, has constant existential humor. Lolling at their bare dining table, the boys are startled to see the camp's guard dog spontaneously taking a walk on his hind legs. Herzog is such a surgical and precise filmmaker that the instances of savagery aren't unbearable. He is not a manipulator who demands that you feel every wound. Herzog's sensitivity, underneath that seemingly unfeeling gaze, is the reason why Grizzly Man worked so well.

Bale fits Herzog's scheme perfectly. This hero is as essentially gentle as he is essentially strange and unknowable. Insisting on the apolitical simplicity of Dengler, Bale sidesteps the rights or wrongs of the Vietnam War. Herzog has made the kind of movie that can't be made anymore without second-guessing and second thoughts. It's a first-rate adventure movie without theatrical machismo.

Rescue Dawn (PG-13; 126 min.), directed and written by Werner Herzog, photographed by Peter Zeitlinger and starring Christian Bale, opens July 27 at selected theaters.

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