Jocasta tells Oedipus and Creon that it's shameful to have public arguments when the city is suffering. When she learns that Oedipus wants to have Creon banished or killed, Jocasta begs Oedipus to believe Creon. The chorus echoes her plea. Oedipus thinks that this means the Chorus also wants to see him overthrown. The chorus swears they don't.
Oedipus remains in a high state of agitation. He is defensive and still inclined to see a conspiracy. Some critics have argued that Oedipus is so quick to see conspiracies because he actually senses his own guilt, but is trying to hide from it.
Moved by the chorus's expression of loyalty, Oedipus allows Creon to go free, though he says that he still doesn't believe that Creon is innocent. Creon exits, declaring that Oedipus is both wrong and stubborn.
Jocasta asks how Oedipus's argument with Creon started. Oedipus tells her that Creon sent Tiresias to accuse Oedipus of Laius's death. Jocasta responds that Oedipus shouldn't worry about the seer's accusation because the revelations of prophets are meaningless.
Jocasta tells a story from her past: When Laius and Jocasta were still married, an oracle told Laius that he would be killed by his own son. In response, when Jocasta and Laius's son was three-days-old, his ankles were pinned together and one of Laius's servants left him to die on a mountain. Laius was not killed by his son, but instead by strangers, at a place where three roads meet. So, Jocasta concludes, seers don't know what they're talking about.
Jocasta once believed in oracles enough to sacrifice her infant son. But now that she's sure the prophecy didn't come true, she no longer believes in prophecies. But in explaining why she doesn't believe in prophecies, she provides the details that make Oedipus suspect the prophecy might be true. Like Oedipus, she dooms herself.
Jocasta's story troubles Oedipus, so he asks Jocasta for more details about the murder of Laius. He grows even more concerned when she tells him that the murder took place just before Oedipus arrived in Thebes, and describes what Laius looked like and how many men accompanied him. Now truly worried, Oedipus asks Jocasta to send for the lone survivor of the murder of Laius and his men to come to Thebes and tell them what he saw that day.
While Oedipus was quick to accuse Creon, he is just as quick to abandon his conspiracy theory once new evidence arises. Now he's back in detective mode.
Jocasta asks to know what's troubling Oedipus. Oedipus tells her his life story. His father Polybus and his mother Merope were king and queen of Corinth. One day, at a banquet, he heard gossip that the king and queen were not really his parents. To learn the truth he went to the oracle at Delphi, where he received a prophecy that he would sleep with his mother and kill his father.
Oedipus reveals the second major prophecy of the Oedipus story. The first prophecy, given to Laius and Jocasta, mentions only that the son would kill the father. The prophecy given to Oedipus brings up the other shameful atrocity: incest.
Terrified, Oedipus never returned to Corinth in order to ensure that the prophecy would not come true. As he wandered, he one day reached the place where Jocasta says King Laius was killed. There he had an incident with a group of men who pushed him off the road and tried to kill him. He defended himself, and ended up killing them. Oedipus now fears one of the men he killed was Laius, and the curses that he himself showered upon the old king's murderer will now come down upon his own head.
When he realizes that he may have killed Laius, Oedipus worries that the punishment of exile that he promised for Laius's killer will fall on his own head. That would be bad enough—by his own decree, he would be banished. But because he still thinks he thwarted the prophecy by leaving Corinth, however, he doesn't realize that the gods will punish him as well.
The chorus tells Oedipus to remain hopeful until he questions the witness he has sent for. Oedipus takes heart—after all, the witness, a shepherd, had said that a group of thieves killed Laius, not just one man. Jocasta also tells him not to worry, because the murder of Laius does not fit the prophecy anyway. Apollo said that her son would kill her husband, and her son was left to die in the mountains. They exit.
Oedipus gets some reprieve from his fears and doubts. If he investigates no further, he can walk away believing that he isn't the murderer of Laius. Yet in believing that the prophecies have not come to pass he too is now dangerously close to denying the power of the gods.
The chorus, alone on stage, chants about the gods who rule the world from Olympus, striking down those who gain power by disregarding the gods' laws and protecting those men who faithfully serve the state. But then the Chorus goes on to say that if a sinner is not punished or if the prophecies and oracles of the gods turn out to be untrue, then there is no reason to worship or have faith in the Gods.