I Know Who You Are plot recap, spoiler-light
The story begins in October 1949 as the People's Republic of China is founded. Xiao Dali transitions from a soldier into a dedicated public security officer in the new regime. He crosses paths with Feng Jingbo, a primary school teacher whose unexpected knowledge of ceremonial cannons triggers Xiao's acute suspicions.
Unbeknownst to anyone else, Feng is actually a left-behind Kuomintang intelligence agent holding the code number 5182, having received lingering orders from his superior Yan Diankun before the Nationalist retreat. Driven by stubborn vigilance, Xiao decides to move into Feng's hutong to keep a watchful eye on him. This sparks an intense ideological rivalry that spans more than thirty-five years.
As China undergoes massive historical upheavals, including the Great Leap Forward, the Cultural Revolution, and the dawn of the Reform and Opening Up period, the two men play a continuous game of cat and mouse. They age side-by-side as ordinary neighbors, their lives permanently intertwined by suspicion, proximity, and an unyielding silent struggle.
