The citizens believe that Oedipus has brought a plague upon the city because he is an impure and cursed individual, and they demand that he be punished for his crimes. Creon, Oedipus's brother-in-law, also accuses him of trying to usurp the throne of Thebes, further adding to the view of accusations against Oedipus.
As the play unfolds, it becomes clear that Oedipus is indeed guilty of the crimes he is accused of, although he committed them unknowingly. He killed his father, Laius, in a fit of rage and unknowingly married his mother, Jocasta. Oedipus's tragic downfall is a result of his fate, which he struggles against but ultimately cannot escape.