In the Nanjing Massacre of 1937, in order to save his life, postman A Chang pretended to be a photo developer in a photo studio and developed photos for the Japanese army. He also took in a group of Chinese soldiers and civilians, turning the studio into a temporary shelter. However, in the face of the Japanese army's cruel atrocities, A Chang risked his life to safely transfer the refugees and exposed the evidence of the massacre to the public.