Su Lin, a young girl, was neglected by her parents since she was a child and grew up in a poor and difficult environment. However, she always studied hard and looked forward to the future.Su Lin worked hard to practice speaking and won the role of Runaway Princess in the English recitation drama, which made her classmate Ma Na jealous.During a fierce conflict, she accidentally fell into an underground pipe, and her life or death was unknown.

At this time, the case of three female corpses in the city's underground river was also exposed to public view. In an instant, the investigation of the case was closely intertwined with Su Lin's fate.Gu Hao, a retired policeman, and Jiang Ting, a girl from the same school who met unexpectedly, have always been concerned about Su Lin's situation.

When Su Lin finally returned to the ground, she encountered the truth about the case of three female corpses. She did her best to help the police bring the criminals to justice.