n ancient Mytilene, a young warrior, Phaon, leads a revolt against the rule of the despotic Melanchrus. Wounded in battle, Phaon takes refuge in the Temple of Aphrodite, where he falls in love with the beautiful Sappho; but when one of the temple maidens betrays him, he is forced to flee Mytilene by ship. After his vessel runs into a storm, he is taken by the Sirens to the undersea palace of Poseidon. When he is about to be sacrificed, Sappho saves his life by appealing to Amphitrite, Poseidon's wife. Returning to Mytilene, he masquerades as a king's guard and continues to lead his revolt against Melanchrus; but he is discovered, captured, and sentenced to death. Sappho saves him once again by agreeing to marry the villainous Hyperbius, the king's chief guard. Though Phaon is sent into exile, his men bring him back to Mytilene to carry on the rebellion. Now Phaon learns that Sappho has forsaken all men and pledged herself to Aphrodite; but once he has overthrown Melanchrus and Hyperbius, Phaon persuades her to renounce her vows and become his wife.