Philoctetes, a Greek hero, owns the bow of Heracles (a gift to the demi-god from the god Apollo) that the Greeks have been told by an oracle they need to win the Trojan War. It isn't entirely clear from the oracle whether Philoctetes is needed to wield the bow. Philoctetes blames Odysseus and the sons of Atreus (Agamemnon and Menelaus) for his ill-treatment. Like Achilles, he is willing to nurse his grudge although it hurts even the blameless Greeks. Left isolated, Philoctetes has been using the special weapon for the undignified task of killing his own food. Heracles comes in at the end as a deus ex machina to make Philoctetes do the right thing.
See "The Role of the Bow in the Philoctetes of Sophocles," by Philip Whaley Harsh.The American Journal of Philology, Vol. 81, No. 4. (Oct., 1960), pp. 408-414.
"Neoptolemos' Story in the Philoctetes," by Richard Hamilton. The American Journal of Philology, Vol. 96, No. 2. (Summer, 1975), pp. 131-137.