Phaedra married Theseus who has a son, Hippolytus, from a previous marriage to Antiope. The young Hippolytus, however, angered Aphrodite by shunning her worship and devoting himself entirely to Artemis, the virgin goddess of the hunt. To punish him, Aphrodite compels Phaedra to begin lusting after the young man. At first, she resisted, and sought magic cures for her passions, or at least a noble death. Hippolytus learns of Phaedra's desire for him through Phaedra's nurse and launches into a fierce denunciation of women -- a locus classicus for misogyny.
Out of shame and guilt Phaedra hung herself, but not until she'd left a letter condemning him of trying to rape her. Hipploytus was trapped into silence because he had promised that whatever Phaedra's nurse told him, he would never repeat. Therefore, when confronted by his father he was defenseless. Out of anger Theseus asked Poseidon to punish Hippolytus, which he did. Hippolytus died as Poseidon's bull emerged from the sea frightened his horses. Unfortunately, after it was too late, Artemis revealed the truth to Theseus concerning his son and Phaedra.
In a typical Euripidean deus ex machina, the goddess Artemis is questioned as to why she stood by and allowed her devoted follower to be destroyed. She reminds the chorus that there is an agreement among the gods that the favorites of one divinity can be destroyed by another divinity at will. It is scant consolation that she promises that someday she'll similarly destroy a mortal favorite of Aphrodite in revenge. And so "As flies are to wanton boys, are we to the gods. They kill us for their sport" (Shakespeare, "King Lear").