Most good stories start with a fundamental list of ingredients: the initial situation, conflict, complication, climax, suspense, denouement, and conclusion. Great writers sometimes shake up the recipe and add some spice.
Initial Situation
Orestes arrives in Argos with the Tutor.
The early stages of The Flies are focused on the setting and mood: what is Argos like? Who are its citizens and how do they live their lives? Because we watch the action through the eyes of Orestes – a foreign visitor– we encounter the town as an outsider.
Conflict
Orestes isn't satisfied with being light and weightless; also, the town of Argos is enslaved by fear and remorse, and Electra is waiting for something…
It seems pretty clear that Orestes wants to commit to something and to take on real responsibility. We also start to suspect that Electra is waiting for her brother to return to Argos, in the hope that he will avenge their father's death.
Complication
Electra rebels, fails, and is exiled. Orestes reveals his true identity; confused, he asks for help from the gods
The plot thickens as the two young siblings have to deal with several external systems of order: that of the gods, that of the King and Queen, and that of "fate." Orestes is confused and unsure of what to do, and Electra flip-flops back and forth between rebellious teen and passive coward.
Climax
Orestes has an epiphany; he chooses and then he acts
It's no coincidence that structurally this falls at the center of The Flies. The most important moment for Orestes comes at the end of Act II, Scene i, when he encounters the anguish of personal freedom and decides to act on it rather than flee from it.
Suspense
On the run
Now that the murders are done, Electra and Orestes are on the run and have taken sanctuary at the feet of Apollo's statue. Because The Flies is a philosophical play and not an action thriller, we're not so much looking for a heart-pounding chase scene as we are interested in what's going to happen to Electra. Orestes's resolve is certain, and we don't really doubt his convictions. But Electra is wavering…
Denouement
The Big Debate between Zeus and Orestes
This is where Sartre explains much of his philosophy. Orestes is given the opportunity to reflect on his actions and explain his choices to Zeus. This is a chance for Sartre to explain his philosophy to the audience. This is where The Flies deals with ideas like freedom and responsibility, consciousness, and being-for-itself.
Conclusion
Orestes's Coronation Speech
Orestes decides where to go from here. Choosing to be "a king without a kingdom," he leaves the freshly liberated citizens of Argos to walk free in the sun.