I applied for a special job - keeping vigil in a century-old courtyard. From ten o'clock to six o'clock in the morning every night, I lived in the courtyard and could not leave. In the first month, she heard someone talking and saw shadows moving, and she was scared to death. Later it was discovered that those were the people who had lived there for hundreds of years, repeating their previous lives. She started chatting with them and listened to them talk about the Republic of China, the Anti-Japanese War, the founding of the country, and reform and opening up. A year later, she became the person who knew the city's history best.