As Salome begins, the Young Syrian, the Page of Herodias, the Cappadocian, the Nubian, and a number of soldiers stand on a great terrace in the palace of Herod. It is night, and the moon is shining. Towards the back of the set, there is a large cistern in which Jokanaan, the prophet is imprisoned. The Young Syrian repeatedly speaks to the Page of how beautiful Salome is, but the Page tells the Syrian that he should not look at Salome so much, that something terrible will happen.

The two also discuss the moon. To the Page, the moon seems like a dead woman. For the Syrian, the moon is a dancing princess. The Cappodocian, the Nubian, and the soldiers discuss various beliefs about the nature of God or the gods. The first soldier says that the Hebrews worship a God that cannot be seen, and the Cappadocian sees no sense in such a belief. In his country, there are no gods left. From the cistern, Jokanaan speaks of the coming of Christ, and there is some discussion of the nature of Jokanaan's prophecies, of whether the prophet is a holy man or is only ‘‘saying ridiculous things.’’

Salome enters, saying she can no longer stay in the banqueting hall with Herod and Herodias. To Salome, the moon is a virgin—‘‘She has never defiled herself.’’ Salome hears the voice of Jokanaan and says she must speak with him, that he must be taken out of the cistern. At first, all say that Jokanaan cannot be removed, but finally the Syrian is persuaded by the princess's charms to bring him forth. Jokanaan is released and begins to speak against Herodias, Salome's mother.

Salome is fascinated by the prophet. At first she tells him that his body is beautiful, but he insults her, calling her the Daughter of Babylon, telling her not to speak to him. She speaks further of his appearance, saying that his hair is terrible but that she desires his mouth. She tells him to let her kiss his mouth. He continues to insult her, and she repeatedly responds, ‘‘I will kiss thy mouth.’’ The Syrian begs Salome to stay away from Jokanaan, but she will not listen, and he finally kills himself in despair, falling between them. Jokanaan tells Salome to seek the Son of Man, but when she continues to tell him to let her kiss his mouth, he says she is accursed and goes back into the cistern.

Herod, Herodias, and the rest of the Court enter. Herod slips in the blood of the Syrian. When he is told the Syrian has killed himself, Herod says that he is sorry but that the Syrian looked at Salome too much. Herodias repeatedly says that Herod himself looks at Salome too much. Jokanaan's voice is again heard, prophesying, and Herodias says the prophet constantly insults her and that he must be quiet. Herod says that Jokanaan is a holy man and that he has seen God. Jokanaan says that the Saviour of the World has come. When Herod assumes that the prophet refers to Caesar, two Nazarenes respond that Jokanaan refers to the Messiah, who has come and is working miracles. When told that the so-called Messiah is healing the lepers and the blind and raising the dead, Herod says that the man must be found and told that he cannot raise the dead, that the king will not permit it.

Jokanaan continues to speak against Herodias, and the queen complains to Herod, but Herod says that his marrying Herodias, who was his brother's wife, is the cause of Jokanaan's terrible words. The prophet says a terrible day will come that the moon will turn to blood. At this point Herod asks Salome to dance for him, but she refuses. He tells her that if she dances for him, he will give her anything she asks, even if it is half of his kingdom. Herodias tells Salome not to dance, but the princess says she will dance for Herod. Herod then points out that the moon has become as red as blood, as Jokanaan predicted.

Herodias implores her daughter not to dance, but Salome dances for Herod. After she has finished, Herod asks her what she wants as her reward. Salome answers that she wants the head of Jokanaan.

Herodias approves of Salome's request, but Herod is terrified. He begs Salome to ask for something else. He offers her his great emerald and fifty of his peacocks, but she repeats her request: the head of Jokanaan. Herod tells Salome that Jokanaan is a man of God and that great misfortune will come if he dies, but Salome persists. Herod finally takes the ring of death off of his finger and gives it to a soldier, who hands it to the executioner. The executioner goes down into the cistern.

Salome listens as Jokanaan is killed and wonders why the prophet does not cry out. The executioner brings forth the head of Jokanaan on a silver shield. Salome seizes the head and speaks to it, saying that now she will kiss Jokanaan's mouth; she will ‘‘bite it like a ripe fruit.’’ Herod says that Salome has committed a great crime and demands that the torches be put out. He begins to climb the stairs as Salome continues to speak, saying that now she has kissed the mouth of Jokanaan. Herod turns toward Salome, crying, ‘‘Kill that woman!’’ The soldiers crush Salome.