Outside King Herod’s palace, captain Narraboth admires the beautiful princess Salome, who is inside at a banquet with her stepfather, Herod, and his court. A page warns Narraboth that something terrible might happen if he continues to stare at the princess, but Narraboth won’t listen. The voice of Jochanaan is heard from the cistern, where he is kept prisoner, proclaiming the coming of the Messiah.  Two soldiers comment on the prophet’s kindness and Herod’s fear of him.

Salome exits the palace, disgusted by Herod’s advances toward her and bored by his guests. Jochanaan’s voice is heard again, cursing the sinful life of Salome’s mother, Herodias. Salome asks about the prophet. The soldiers refuse to allow her to speak with him, but Narraboth, unable to resist her, orders that Jochanaan be brought forth from the cistern.

At first terrified by the sight of the holy man, Salome quickly becomes fascinated by his appearance, begging him to let her touch his hair, his skin, and his lips. Jochanaan forcefully rejects her. Narraboth, who can’t bear Salome’s desire for another man, stabs himself. Salome does not notice and continues to beg for Jochanaan’s kiss. The prophet shames her and retreats into the cistern, cursing Salome.

Herod appears from the palace, looking for the princess and commenting on the strange look of the moon. When he slips in Narraboth’s blood, he panics and has hallucinations. Herodias angrily dismisses his fantasies and asks him to go back inside with her, but Herod’s attentions are now focused on Salome. He offers her food and wine, but she rejects his advances.

From the cistern, Jochanaan resumes his tirades against Herodias, who demands that Herod turn the prophet over to the Jews. Herod refuses, maintaining that Jochanaan is a holy man and has seen God. His words spark an argument among the Jews concerning the true nature of God, and two Nazarenes talk about the miracles of Jesus. As Jochanaan continues to accuse her, Herodias demands that he be silenced.

Herod asks Salome to dance for him. She refuses, but when he promises to give her anything she wants, she agrees. Ignoring her mother’s pleas not to, Salome dances seductively, removing her clothes. The delighted king wants to know what reward she would like, and she innocently asks for the head of Jochanaan on a silver platter. Horrified, the king refuses, while Herodias laughs approvingly at Salome’s choice. Herod offers other rewards, but Salome insists and reminds Herod of his oath. The king finally gives in. As the executioner descends into the cistern, the princess anxiously and impatiently awaits her prize. When the prophet’s head is brought to her, she passionately addresses Jochanaan as if he were still alive and finally kisses his lips. The terrified Herod orders the soldiers to kill her.