The body of a professor is discovered at a university lecture hall suspended from the ceiling of the stage, with a series of mysterious numbers written on the curtains nearby. Professor Eiko, a law professor at the university well versed in criminology, is asked to assist police in the investigation, and he uncovers clues that point to him as a suspect. Why is he being set up? As he and his assistant work to decipher the code left on the curtains, another professor at the university is murdered. And yet another mysterious code is left at the scene of the crime.