Down a tree-lined alley in central Beijing, behind grey courtyard walls wrapped with barbed wire, lives a frail old man - a symbol of democracy that the authorities fear they cannot control.
Zhao Ziyang , the former Communist Party general secretary, has lived under house arrest in this spacious home for 15 years.
On May 19, 1989, he made an ill-fated trip to Tiananmen Square where thousands of students were on a hunger strike. Mr Zhao begged the students to end their protest. At his side that day was Wen Jiabao , the current premier.
With tears in his eyes, Mr Zhao said he had come too late. 'Fellow students, this is the last time I can meet with you,' he said. He has not been seen in public since.
The next day, martial law was declared. After June 4, a government report said: 'Comrade Zhao Ziyang committed the serious mistake of supporting the turmoil and splitting the party. He had the unshirkable responsibility for ... the turmoil.'
On June 24, Mr Zhao was purged of his posts and was replaced by Jiang Zemin , who was then mayor of Shanghai.
Rumour has it that Mr Zhao, 84, is suffering heart and lung problems. Party officials fear his death could become a rallying point for reformists and others disgruntled about issues ranging from corruption to the widening gap between the rich and poor.