Captain Narraboth and some of his soldiers are watching King Herod, his wife Herodias, and her daughter Salome, who have gathered for a banquet. Narraboth is infatuated with Salome; a colleague tries to divert his attention from her but is unsuccessful. The voice of the prisoner Jochanaan repeatedly intrudes on the scene, heralding the coming of the Messiah.
To Narraboth’s delight, Salome emerges, unable to endure another moment at the banquet table; her stepfather Herod’s wanton glances are as disagreeable to her as the conversations of the guests. Jochanaan’s voice is heard again, arousing Salome’s curiosity. She declines to return to the banquet, demanding instead to speak with the prisoner. The soldiers explain that Herod has forbidden all contact with him, but Salome persuades Narraboth, whose passion for her has not remained secret, to grant her wish.
The prisoner is brought before her. He condemns Herod’s marriage to Herodias as a violation of Jewish law and accuses Herodias, in particular, of leading a disgraceful life. Salome appears to grow more and more fascinated – first by Jochanaan’s voice, then by his body. Unmoved by the prisoner’s resistance and revulsion, she moves in close and importunes him. He exhorts her to seek religious purification. When she insists on kissing him, he curses her.
Herod and Herodias are in disagreement – and not only over how to deal with Jochanaan. Herod, plagued by dark premonitions and symptoms of disease, sees him as a prophet, whereas Herodias finds the prisoner irritating and would prefer to hand him over to the Jews. Herod makes ambiguous overtures to Salome, holding out to her the prospect of her mother’s throne. Into this poisoned atmosphere, the voice of Jochanaan interjects itself once more.
While the Jewish guests at the banquet argue over questions of religion, Jochanaan announces the Messiah’s arrival. Two Nazarenes declare that they too believe the Messiah to be the miracle-working itinerant preacher of whom Jochanaan speaks. As the celebration threatens to spiral out of control, Herod orders his stepdaughter to dance for him. She agrees on the condition that he promise to give her whatever she wishes afterward.
After the dance, Salome calls for Jochanaan’s head on a silver platter. She rejects each of the horrified Herod’s counteroffers, as well as the support of her mother: »I desire Jochanaan’s head for my own pleasure.« Herod gives the order for Jochanaan’s beheading. Salome is given the head and takes what the prisoner had denied her: she kisses Jochanaan’s mouth.
Herod commands that Salome be executed as well.