Jean-Paul Sartre's dramatization of the myth of Electra. The city of Argos is plagued by flies and remorse after the Argives allow their king, Agamemnon, to be murdered. Ultimately a rather graceless argument for existentialism concluding with Orestes' rejecting Zeus in favor of free will.
Sartre based his interpretation its three major predecessors: Sophocles' Electra, Euripides's Electra and Aeschylus's Oresteia. The play was written in Nazi-occupied Paris in 1943 and, according to Wikipedia, it premiered in New York City on April 16, 1947.