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.