The two stayed in their hiding place until the wee hours of the next day, when they got into a pre-arranged car and drove out of the just-opened city gate, Helen wearing sunglasses and a man's suit, posing as the diseased son of an American missionary.

A boat ride followed, at the end of which Snow found herself in the territory of the Communists.

But it took another bumpy day on a truck before she arrived in Yan'an late on May 2, 1937.

Early the next day, Helen, fazed and fatigued, awoke to the news that Mao Zedong and Zhu De, who would become the chairman and vice-chairman of the People's Republic of China in 1949, wanted to see her.

"Helen evoked that experience in her book Inside Red China," said An, an English major who as a young man yearned for English books. "I encountered her book, together with Edgar's Red Star Over China, in the small library at the Yan'an History Museum, where I worked in the early '70s." He read both voraciously.

So when Helen visited in 1978, An felt the heroine had finally stepped out of the pages. "At my mentioning of the hotel, Helen turned to my boss and said, 'This young gentleman has got to sit in my car'," said An, who had no idea at the time that the trajectory of his life, like those of many who crossed paths with Helen, was about to change.

"She was the star who pulled us into her orbit," An said.

In 1931, when Helen, then 24, had arrived in China and worked in the US consulate in Shanghai, she became the belle of the foreign concessions.

Yet she was not going to spend the following years twirling on the dance floor, as many of her fellow expatriates did.

Edgar, who had arrived in China three years earlier, took her to the world outside the walls of her residential enclave, a world wracked by war, and famine.

The two married on Nov 25, 1932, and moved to Beijing, where they became involved in student movements that were about to sweep across the country, in reaction to Japan's growing territorial ambitions in China.