A standoff between a policeman and a spy becomes a tender portrait of ordinary lives. In the early days of the People's Republic, police chief Xiao Dali (Lei Jiayin) follows his instinct to the spy "5182"—Feng Jingbo (Hu Ge), lying low at No. 15 Tutangdao Lane. To uncover the truth, Xiao moves into the same courtyard, and hunter and quarry become everyday neighbours. What grows between them shapes the fate of two families across two generations. After half a lifetime of storms, these lifelong adversaries are no longer simply enemies.
