The young captain of the guard Narraboth's gaze lovingly follows Salome, who is feasting with the guests of King Herod. Herodias' page, amazed at the unusual moon, warns his friend of danger. From the dungeon the voice of the prophet resounds, announcing the birth of the Son of God: "When He comes the desolate places shall rejoice, the eyes of the blind shall see the day and the ears of the deaf shall be opened."
Followed by the lustful glances of her step-father, Salome leaves the feast. The threatening speeches of Jokanaan awaken her curiosity, and the princess wishes to see the prisoner. She gently asks Narraboth to do this and he, unable to resist her charms, breaks the tetrarch's orders. Jokanaan denounces Herod and Herodias, covered in sweat and tears, and he calls on them to repent. Desiring to be caressed and kissed, Salome tries to approach the prophet, but he spurns the "daughter of Sodom". Amazed at what he has seen, Narraboth killed himself. Cursing, Jokanaan retreats to his cell.
Haunted by nightmarish visions bordering on hysteria, the tetrarch seeks out his step-daughter. He offers Salome wine and exotic fruit as well as a seat at the feast next to him. Yet she coldly rejects his advances. Again the threatening prophecies of Jokanaan are heard. Herodias asks for him to be given to the Jews, but Herod is fearful of issuing such an order as he considers Jokanaan to be a holy man. The Nazarenes speak of the miracles of the Messiah which they have witnessed. In the hopes of distracting himself from his gloomy thoughts, the tetrarch convinces his step-daughter to dance for him and, for the pleasure, he will grant her every wish. Taking Herod on oath, Salome begins her dance of the seven veils.
Herod is delighted and he asks what the reward should be. Salome demands the head of Jokanaan. Sensing impending doom, Herod tries to pay by other means, but the princess insists. The tetrarch is forced to fulfil his promise. Salome is given Jokanaan's head.