Epiphyllum Dream.

In a desperate hunt to track down a top-secret metal box during World War II, China's best forensics experts are called to duty. The year is 1945, and an iron box containing the top-secret files detailing the Japanese biological weapons program go missing. Police director Mo Caishi (Gang Wu) assigns top police detective Cheng Cihang (Zhenyu Qiao) to help track down the missing files.