For weeks, Chen Guangcheng pretended to be sick.

Living under the watchful eye of the world’s biggest security apparatus, his every movement closely monitored, the self-trained lawyer was hoping his jailers would let down their guard. On Sunday, they did.

Under a moonless sky, Chen scaled a high wall and fled the darkened village where he had been confined to his home for the past year and a half, according to a version of events provided by friends. From there, he traveled nearly 400 miles to Beijing and, perhaps, to freedom.

His escape was made all the more remarkable by a simple fact: The 40-year-old Chinese dissident has been blind since childhood.

As of Saturday morning in China, Chen’s exact whereabouts were unknown, but friends insisted he was “safe” — and suggested that the only truly safe place for him in China was under the protection of U.S. diplomats.

ChinaAid, a Texas-based Christian human right group, said Chen was under the protection of U.S. officials and talks were underway between U.S. and Chinese officials about his fate. The U.S. Embassy, however, maintained its silence, declining to either confirm or deny that Chen was there, with a diplomat citing the sensitivity of the situation.

“His story,” said friend and fellow activist Hu Jia, “is the Chinese version of ‘The Shawshank Redemption.’ ”

And just as in the movie, Chen had clearly thought far ahead when plotting how to elude his captors. Soon after his disappearance became publicly known Friday, his face was beamed around the world in a video released by a U.S.-based rights group. In it, he directly addresses his country’s prime minister, Wen Jiabao.

Wearing his trademark dark glasses and speaking calmly into the camera, he details layers of security imposed around his tumbledown home and says that reports of abuse he suffered while under effective house arrest “are all true. And the reality is more serious than the descriptions online.” Chen says he still fears for his family. “My mother, my wife and my children are still in their clutches,” he says.

This was not Chen’s first attempt to break free, nor was it the first time he has caused international embarrassment for the Chinese government.

His flight is a severe blow to China’s vast and lavishly funded internal security system. China, according to budget figures released last month, will spend $111 billion on internal security this year — $5 billion more than the military will get. But Chen’s escape has exposed the cracks in a system that can often seem invincible. It has also highlighted the role of one of the Communist Party’s biggest irritants — a network of well-organized and committed activists ready to take grave personal risks to combat what they see as intolerable injustices.

By escaping, and by perhaps placing himself under the protection of U.S. diplomats in China, Chen has managed to place the spotlight on human rights just as Chinese authorities are reckoning with the fallout from the country’s messiest leadership struggle in decades. The action also comes on the eve of a visit by U.S. Secretary of State Hillary Rodham Clinton, who has repeatedly called for Chen’s release.

Chen, a prominent legal activist who infuriated party officials by rallying opposition to forced sterilizations and other aspects of China’s family-planning regime, was jailed from 2006 to 2010 and then vanished into a harrowing legal twilight zone, held prisoner at his home in Shandong province by a small army of local police and hired thugs.

Chinese dissidents and friends of Chen’s in Beijing said the blind lawyer first tried to escape last year by digging a tunnel with his family members. But guards quickly discovered it, foiling the plan when the tunnel was only a few yards long.

After Chen’s escape, a friend named He Peirong, also known as Pearl, drove him to Beijing. U.S. officials declined to comment Friday on reports that Chen was hiding at the U.S. Embassy. Dissidents who declined to be named for the record said He did not take Chen directly to the U.S. diplomatic mission because it would have been too dangerous. Instead, the dissidents said, she returned to her home in Nanjing after dropping Chen off in the distant capital.

ChinaAid reported that He was arrested Friday at her home in Nanjing.

Chen’s success in eluding the legions of police and plain-clothes security agents that blanket much of China adds another layer of mystery to a case that has long caused bafflement. Chen’s treatment violated China’s laws and continued despite causing severe damage to China’s image and the leadership’s oft-declared goal of establishing rule-by-law.

“How does a blind guy like this get away? It seems almost impossible,” said John Kamm, the founder and head of Dui Hua Foundation, a group that has for years lobbied Chinese authorities to free jailed dissidents or improve their prison conditions. “The hunt will now be on for those who may have helped him.”

Despite strong evidence that Chen’s treatment in Shandong broke Chinese law, officials in Beijing routinely brushed aside a chorus of criticism at home and abroad, and stood by local party officials responsible for Chen’s extra-legal detention. Kamm said that whenever he raised Chen’s case in Beijing, officials suggested that Shandong officials alone were responsible and that the central government could not do anything to help.

Before his escape, Chen was technically free but under 24-hour surveillance and barred from making phone calls or receiving visitors. Attempts to visit him by friends and supporters led to often-violent confrontations with a phalanx of unidentified men stationed around his house in a rural district of Shandong’s Linyi City.

Chen nonetheless occasionally managed to make contact with the outside world — and suffered severe beatings as a result. That happened last July when a rainstorm knocked out a telephone jamming device installed by authorities and he was able to call friends for the first time in months.

Richburg reported from Beijing.