1. Oedipus and Jocasta
* Oedipus's Messenger: In Oedipus's palace, a messenger arrives and tells Oedipus that his father has died and that he could ascend the throne of Corinth. The audience knows that this news is ironic, as Oedipus has unknowingly killed his father, Laius.
2. Jocasta and Oedipus
* Jocasta's Messenger: Upon leaving the palace after a heated argument with Oedipus, a messenger enters and informs Jocasta that she is not Polybus's daughter but rather a princess from Thebes, who was given to the childless couple as an infant to save her life. Both she and Oedipus are shocked and horrified to discover that they are mother and son and husband and wife. Jocasta retreats into the palace, and Oedipus sends for the blind prophet Tiresias, hoping he will reveal the identity of Laius's murderer.
In both instances, the dramatic irony created by the messenger is essential in building tension, developing plot points, and unraveling the tragic narrative.