The mighty tyrant Holofernes, general to the Babylonian emperor Nebuchadnezzar, is engaged in a campaign of terror – leading his armies in an orgy of destruction. His progress is temporarily halted outside the mountain city of Bethulia where a tribe of Israelites have walled themselves in, hoping to survive the onslaught. Holofernes has cut off their water and supplies, and awaits their inevitable capitulation.

The action takes place simultaneously in the walled city and outside in the army camp. The fearful Bethulians, weakened through lack of sustenance, pray for salvation and watch in horror as the Babylonian army sacrifices to pagan gods. Holofernes, brilliant military tactician with a restless and dangerous intellect, offers his men an opportunity to make complaints against their officers. When one soldier accuses his captain of stealing his slave girl, Holofernes condemns both the soldier and officer to death, taking the slave girl for his own pleasure. He muses on one of the greatest sources of his power – his unpredictability. Then he rapes the girl, glorying in his godlike power.

Judith, a beautiful young widow in the besieged city, relates a strange dream to her companion Mirza. Finding herself on a high mountain, she cried out to God and leapt into the abyss. Loving arms caught her and held her, but then let her fall. She confides to Mirza that, although she had been married for six months before her husband’s death, she is still a virgin. Whenever her husband approached her he would sink into strange fits of prayer. Now she lives alone, constantly fasting and praying. Although the people believe her pious and God-fearing, she is miserable and unfulfilled, and cries out at night to an unknown beloved.

The Bethulians are desperate to seek a solution to their impasse. Their High Priest urges patience but Ammon, one of the people, begs them to open the gates and end their slow death by starvation and thirst. His brother Daniel, a prophet, turns on him and harangues the people to stone him to death. They hysterically obey.

A messenger from Nebuchadnezzar comes to Holofernes – henceforth the emperor wishes to be worshiped as supreme god, and all other gods are to be destroyed. As Holofernes oversees the destruction of the idols he is fascinated by the idea of one god, but ridicules the notion that it is his weak emperor.

Judith is visited by Ephraim, a young Israelite who loves her but whom she has rejected. He speaks of the terror in the city, and of the people’s fear of Holofernes and his atrocities, but Judith is fascinated by the tyrant. Again he pleads for her love, but she tells him that there is only one way to win her – he must kill Holofernes. Ephraim fearfully refuses and Judith scornfully sends him away. She has realized that all the Israelite men are gripped by fear, and that she, a woman, must act to save her people.

Achior warns Holofernes that the God of the Israelites is powerful and vengeful – if they have not sinned against Him, He will save them and destroy Holofernes. Holofernes orders that Achior be taken to the walled city and destroyed when the Israelites fall. He makes an oath that if the Israelite God delivers the people into his hands, he will worship that God.

Judith, in despair and driven by the need to act, prays for guidance. She suddenly conceives her plan -through her beauty she will seduce Holofernes, and then kill him. As the desperate Bethulians burn the prophet Daniel and prepare to open the gates and surrender to almost certain death, Judith calms them, prays, and goes forth from the city with Mirza to seek Holofernes.

Outside Holofernes’ tent. Holofernes’ servant tells an officer of an odd occurrence – Holofernes, in his sleep, dreamt he was being attacked and tried to kill himself. Holofernes appears, and meditates on the mystery and attraction of death. Judith, accompanied by Mirza, has reached the enemy camp and is led into his presence. Holofernes desires her. She cunningly tells him many things – that her people have sinned against their God and deserve their punishment – that he should spare them, thereby gaining godlike power. Holofernes mistrusts Judith but enjoys the game. Judith, to her shame, is attracted to him, and they enact a scene of passion and loathing.

Ephraim has broken into the camp, and is led to Holofernes, who assumes he is coming to announce the Israelites’ surrender. When Ephraim clumsily tries to kill him, Holofernes has him thrown into a cage. He brutally orders Judith into his tent.

The terrified Mirza waits alone, sensing impending death. Time passes. Judith, disheveled and shaking, appears. Holofernes has raped her, and is sleeping. She hesitates, almost collapses, then disappears again into the tent, re-emerging with Holofernes’ bloody sword and his severed head. Mirza is in shock. Judith is battered by a series of reactions – disgust, pride, and horror. She proclaims herself heroine and savior of her people – but she admits that her deed was intensely intimate and personal. She slips into madness.

The Israelites, hearing of the tyrant’s death, invade the enemy camp, and indulge in an orgy of blood and revenge. Judith is acclaimed – but Ephraim sarcastically names her Whore of Israel. She kills herself. The Israelites beg their God to save them.