The story is based on real documented evidence of the atrocities committed by the Japanese army during the Nanjing Massacre. A group of civilians hiding in the Lucky Photo Studio to escape the violence are forced to assist a Japanese military photographer in developing film to survive each day. By chance, they develop photographic evidence that exposes the Japanese army's massacre in the city. Initially focused only on surviving the horrors, they ultimately decide to preserve these damning negatives as proof of the atrocities unfolding in Nanjing.