Minghai City policewoman Ji Lingge meets Fa Sai, a delinquent who is a suspect in a murder with no witnesses, and discovers his astonishing talent for "digging holes during interrogations." Soon, another unsolved campus case comes to light. Ji Lingge turns to Fa Sai for help. Though Fa Sai encounters a suspect with the same skill as his own, he still manages to solve the case with ease. But the cases keep coming, and Fa Sai and Ji Lingge begin investigating together: a mysterious fall from a building, a murder in a locked room with a twist... Who is the killer?
