In the late autumn of 1937, in order to escape the war, Chinese doctor Cheng Xian (Qin Han) fled from Shanghai to his hometown in Nanjing with his pregnant Japanese wife Rieko (Saoyi Nvyai) and their children. He did not expect that Nanjing would almost be destroyed by the Japanese invaders. Ruins. When told that he could take refuge in a safe area protected by European and American powers, Cheng Xian thought that his status as a refugee was different and ignored it. He turned to old friends and continued to practice medicine. He was shocked and angry by the tragedy of his compatriots represented by primary school teacher Liu Tianqin (Liu Ruoying), but he believed that his first task was not to resist the violent enemy but to be a good doctor. On December 13 of the same year, Nanjing fell completely. The Japanese army began to burn, kill and plunder crazily in Nanjing. Chengxian finally realized the cruelty and numbness of the Japanese army and asked his wife to go to the safe area to escape, while he stayed behind to continue saving lives. What he didn't know was that the safe area had long existed in name only, and when he wanted to resist, he found that it was no longer possible.