This drama tells the story of a serial murder case that broke out in Wangye Town in 2008. Aoi Kiryu lost her family, friends and love in the case, and her father became a suspect and was arrested. 16 years later, detective Aoi returned to her hometown to investigate the truth and found that her classmates might be suspects, while her partner Xiangsaka Hui was monitoring and suspecting Aoi. In the process of tracking down, she revealed the truth about her classmates and Hui's past, as well as the connection between the two incidents. Then, a truth that had been hidden for 16 years surfaced.