When told to analyze a play, take Oedipus the King by Sophocles as an example, there are many ways in which you could do so such as explaining their ideas, theories, images and symbols. The images of the plague, blood, and birds convey the darkest images that Sophocles wanted to bring to his listeners.
The image of the plague is brought to attention in the beginning of the play once Oedipus had already been King for multiple years, married to Jocasta, who is both his mother and wife and has 4 children, whom are also his much younger brothers and sisters. The city of Thebes has sent to the castle of Jocasta and Oedipus, and the Priest told Oedipus that the "Plague has settled on our city like a fire, Consuming everything that lies before it- Soon the streets will be gaunt and empty; soon Hell's jaws will gape to swallow us alive. (1.1)"
In the Priest's speech, it shows the power that the plague has over the city of Thebes, the speed that it's consuming the people and animals, the fear that the people have of the sickness and that nothing man made may be able to slow it down or stop it. Sophocles personifies Hell by saying that "Hell's jaws will gape to swallow us alive" which gives Hell a figure, such as Cerberus, the three headed dog that guards the Underworld, giving it something for the people of Thebes to fear at night while they are attempting to sleep. The speech also is very poetic in that you can easily imagine what's going on in it, a dark, epic fire roaring through the city and after it tears it apart, a mouth forming in the middle of the kingdom, completely consuming Thebes like an evening meal.
Further on into the first act, Creon returns from Delphi with news from the God's about how to rid the city of the plague. Creon returned with the news that it's "By finding and punishing a murderer- it's the shedding of unlawful blood that's brought the plague upon us! (1.1)"
This follows on and the listeners learn