Brad Pitt wasn't necessarily Annaud's first choice to play Heinrich Harrer, the real-life Austrian mountaineer who set off to climb a Himalayan peak and ended up escaping from a British prisoner-of-war camp and meeting the young Dalai Lama-and being spiritually transformed to boot. But Pitt "charmed me and seduced me," says Annaud. "I think Brad badly wanted to have this experience."

Some experience. Pitt and Thewlis, who plays Harrer's climbing partner, Peter Aufschnaiter, spent two weeks in Austria and Italy for intensive mountain-climbing practice before filming. Unable to shoot in India, as he'd hoped, Annaud and his team moved 200 handpicked Tibetans-100 monks and 100 laypeople-and dozens of yaks to a small town at the foot of the Andes in Argentina, where the film crew recreated a Himalayan village.

"Working with the monks every day was extraordinary," says Thewlis. "If you found yourself with a grudge against someone, you looked twice at your motives-without even realizing it." But not even Buddhist serenity was enough to fend off the fan hysteria inspired by Pitt. Annaud recalls "with terror" their first night in the tiny, remote village of Uspallata, when "zillions of little girls" who had persuaded their parents to drive them miles in search of Pitt descended on the town. "It was embarrassing for him." Says Annaud. "He wanted to play this very conflicted, internal role and here were all these little girls wanting his body." The producers were forced to spend $60,000 to build a 12-foot-high barbed-wire fence around the barracks where Pitt slept.

Wong, who plays a Tibetan courtier in the film, remembers a girl who approached him in the village's only restaurant, saying she had come 200 miles to meet Pitt. Wong later saw her sneaking onto an even more remote location in the guise of delivering ice cream. "It was like on I Love Lucy when Lucy went to Hollywood and wanted to see William Holden," the actor marvels. Despite such intruders, Annaud, Thewlis, and Wong say that making the movie had a powerful emotional effect on them—and on Pit as well. "After a day of shooting, the monks would ask us to do some prayers for the set or for the Dalai Lama's birthday, and we would all stand with them and sing," says Annaud. "Brad was very often in tears."