oedipus the king. the play starts out with two problem what are they

There is a plague and a "mysterious" murderer. When the play opens, Thebes is suffering a plague which leaves its fields and women barren. Oedipus, the king of Thebes, has sent his brother-in-law, Creon, to the house of Apollo to ask the oracle how to end the plague. Creon returns, bearing good news: once the killer of the previous king, Laius, is found, Thebes will be cured of the plague (Laius was Jocasta's husband before she married Oedipus). Hearing this, Oedipus swears he will find the murderer and banish him.