Haruka Nanase is a talented graduate student specializing in genetic anthropology. His life is upended when his mentor, Professor Iwamisaki, asks him to analyze the DNA of 200-year-old human remains discovered at Roopkund Lake in the Himalayas. To Haruka's absolute shock, the genetic results yield a 100% match with Chiharu, his beloved stepsister who disappeared without a trace four years prior. Determined to uncover how such an impossible contradiction can exist, Haruka's investigation triggers a deadly chain of events. Soon after the discovery, his professor is brutally murdered, and the ancient bones are stolen from the laboratory. Alongside a sharp duo of local detectives, Haruka must navigate a labyrinth of corporate cover-ups, scientific taboos, and hidden pasts to solve the murder and find out whether his sister is truly dead or alive.