During the Japanese occupation of Nanking, mass murder, rape, and looting occur. Postman Ah Chang stumbles upon a photography studio where, along with the owner and other civilians in hiding, he is forced to develop photographs taken by Japanese military photographer Hideo Itō. Among the negatives are both doctored propaganda materials and authentic photographs documenting war crimes. They decide to hide the evidence and smuggle it out of the city. Their actions lead to a series of dramatic sacrifices, and the photographs ultimately reach international attention, becoming indisputable evidence in post-war war crimes trials.