Sophocles' Philoctetes was produced in 409, five years after Birds, two years after Lysistrata.
In the interim democracy was overthrown and reestablished; there was a precarious peace within Athens, while war with Sparta continued. The outpost at Decelea kept the city under constant threat of attack.
The situation in the play is this: Philoctetes (title character but not the protagonist) was left behind on a desert island when the Greeks sailed to Troy many years before. He had an infected wound (from snakebite) and his shipmates were horrified by the stench of his wound and his cries of pain; they also associate such infection with (religious) pollution. Now the Greeks have discovered that Troy can only fall if the bow of Heracles comes to attack--and the bow is securely in the hands of Philoctetes.
'Sound contrived? Well, it is perhaps a paradigm for mending old quarrels. It is a rather heavy-handed lesson in loyalty and integrity-- while learning to live with old enemies--much like the theme of Ajax, more than 30 years before.
That is the overriding question: How does this late treatment of the theme differ from the earlier treatment?
The character of Odysseus serves as a sort of yardstick. How is his character different from the role in Ajax?
The young-man-coming-of-age is represented by Neoptolemus, the son of Achilles--who supposedly is also prophesied to seal the doom of Troy.
How does Odysseus first convince Neoptolemus to go against his better nature and trick Philoctetes?
What is it then that leads Neoptolemus to change his mind and take the side of Philoctetes?
How, in the end, is Philoctetes convinced to go along to Troy? By trust in his newfound friend, the noble Neoptolemus?