There is an artificial lake in a research institute of a certain country, and a missing person incident has occurred. One night, technician Ding Xia's girlfriend Li Yun mysteriously disappeared by the lake. The next day, an old lady walking her dog discovered a broken hand... The policeQuickly intervene in the investigation with Captain Wang, the Chinese security guard. Wang's niece Yu Xiaoyi also participated in it. Although Ding Xia has an alibi, he seems to have been harboring a demon in his heart: his sister Ding DongTwo years ago, she committed suicide by jumping into an artificial lake, and Ding Xia often sees her repeatedly appearing in nightmares. During the investigation process, a dusty truth about history was revealed: during World War II, the Japanese army carried out brutal operations in this area, leaving no one behindConduct biochemical experiments on the human body, and cultivate and develop biochemical genetic weapons through radioactive elements. One of the varieties did not detonate during the bombing experiment and fell near the artificial lake. Can Ding Xia uncover her inner demons？ Can Yu Xiaoyi find the culprit of the murder? Everything will come to an end on an uncertain night.