When Peiping fell in 1937, Shen Jingting, the owner of Jingting Tower, clung to his ancestral business. Eight-year-old Shen Yusheng and nine-year-old Zhou Shi'an were separated at Yongding Gate. During the war, she became an intelligence agent in the base area, lurking in the enemy camp with a knife as an edge. Seventy years have passed, and a 29-military copper button finally revealed the watchfulness and regret that spanned life and death.
