Scene 1: Paris, April 1789, the start of the French Revolution. The Chevalier de Force bursts into his father’s library, anxious about his sister Blanche, whose carriage, returning from a church service in Paris, is surrounded by an angry mob. The Marquis reassures his son, but is reminded of the street riot in which he and his late wife were caught. That same night, his wife died giving premature birth to Blanche, an introspective and over-timid child. The Chevalier is concerned about the effect of this latest fright on her fearful and morbid imagination. Blanche has come to no harm, but when she appears exhausted and nervous, she retires to her room. Moments later she reappears, terrified by a shadow, and announces to her father that she feels unable to cope with the daily ordeal of living in the world and has decided to enter the Carmelite convent at Compiègne.
Scene 2: Several weeks later, Blanche has come to the Compiègne to request entry into the convent. Mme. de Croissy, the elderly Prioress, questions her vocation and warns her against seeing the convent as a refuge from the world. She underlines the first purpose of the Order: prayer. Blanche tells the Prioress that should she be accepted, she would like to be known as Sister Blanche of the Agony of Christ.
Scene 3: Blanche has entered the convent as a novice and is working in the turn room with another young nun, Constance de Saint-Denis. Constance’s lighthearted chatter irritates Blanche who scolds her for her good humor at a time when the Prioress is seriously ill. Constance suggests that she and Blanche offer their lives for that of the Prioress, but Blanche violently rejects the idea. Constance tells Blanche that she believes they will both die young, and on the same day.
Scene 4: In the infirmary, the Prioress lies on her deathbed, attended by Mother Marie. She feels isolated and fearful, and unprepared for her coming death despite a lifetime of mediation and prayer. She admits to a particular interest in Blanche, and fears for her well-being. She entrusts Blanche to the care and protection of Mother Marie. Blanche enters the sickroom, and the Prioress tenderly bids her farewell with a final recommendation not to despise herself, but to entrust her honor to God’s keeping. Then as her death agony begins, the Prioress grows delirious and cried out against God, foreseeing the convent chapel empty and desecrated. Mother Marie attempts to keep the other nuns away, but Blanche returns to the room in time to witness the Prioress die in pain and despair.
Scene 1: It is night. The Prioress lies in state in the chapel while Constance and Blanche stand watch. Their watch ends and Constance goes in search of their replacements, leaving Blanche alone with the corpse. She takes fright, but as she attempts to leave is met by Mother Marie, who rebukes her but urges her not to dwell on the incident. Mother Marie escorts Blanche to her cell.
Interlude 1: Blanche and Constance bring flowers for the tomb of the Prioress. Constance hopes that Mother Marie will be chosen as the new Prioress. She outlines to Blanche her theory that the old Prioress’ terrifying death was wrongly assigned by God, and that someone else worthy will therefore benefit from her agony with an unexpectedly peaceful and comfortable end.
Scene 2: The nuns have assembled in the chapter room to meet with the new Prioress, Mme. Lidoine. In straightforward language, she gives her inaugural address to the community, warning that the days of peace and security are over and that unforeseen trials await the nuns. She stresses that whatever threatens, the nuns should not aspire beyond their humble duty of prayer.
Interlude 2: As the national crisis of the revolution heightens, the Chevalier de Force prepares to leave the country and calls secretly at the convent to bid farewell to Blanche. The new Prioress asks Mother Marie to be present at their meeting.
Scene 3: The Chevalier urges Blanche to leave the convent for her own safety and return home to their father. He accuses her of staying in the convent out of fear, or her fear of fear. Blanche maintains that she is now dependent on God’s will and asks him to respect her as a daughter of Carmel who is going into battle in her own way. However, as soon as he leaves, her defiance collapses and she is consoled by Mother Marie.
Scene 4: The Chaplain of the convent has been forbidden to perform his duties and has conducted his last mass. In the sacristy of the convent, he takes leave of the nuns, assuring Blanche that he will remain nearby. Constance is amazed that France will not defend its priests. Seizing on a remark by the Prioress, Mother Marie declares that to preserve the future of the convent and to restore peace to France, the nuns of Carmel need only surrender their lives. The Prioress says firmly that it is not for them to choose martyrdom. The Chaplain, who has been caught in the street between the crowd and a patrol of soldiers, returns to take refuge at the convent. As he makes a second attempt to the convent, the crowd beats against the outer door. Two commissioners announce that the Legislative Assembly has ordered the closure and sale of all religious houses. The nuns must give up their traditional attire and evacuate the convent. Mother Marie suggests again the Carmelites have a role to play- that of martyrs. As the commissioners leave, Mother Jeane announces the Prioress’ departure for Paris. To comfort Blanche, who is terrorized and bewildered, she hands her a statue of the child Jesus. A shout from the crowd outside startles Blanche and she drops the statue, which breaks on the stone floor.
Scene 1: The chapel of the convent has been ransacked and desecrated, and the nuns, now attired in civilian clothes, are gathered about Mother Marie who has command the absence of the Prioress. She proposes that for the preservation of their Order, the nuns take the vow of martyrdom. The wish to do so must be unanimous, but when a ballot is taken there is one dissenting vote. Blanche is suspected, but Constance admits responsibility and asks to reverse her decision. The motion is carried two by two, beginning with Blanche and Constance, the nuns kneel to take the vow of martyrdom. In the confusion, Blanche flees.
Interlude 1: The Prioress has returned and the nuns have left the convent. They are addressed by an officer who welcomes them as new citizens of the republic, but warns them that they will remain under surveillance. He forbids any contact with the priests or the practice of their Profession. The Prioress sends a nun to warn the Chaplain, who had agreed to conduct morning mass for them. Mother Marie feels that this caution militates against the vow they have taken.
Scene 2: Blanche has returned to her father’s house in Paris. The house has been ransacked, and Blanche now lives as a servant of the new occupants. Mother Marie arrives to summon Blanche back to Compiègne for her own safety. Blanche is paralyzed by fear that has assailed her since childhood and resists. She feels unworthy of her father, who has been guillotined, and asks only to be left alone. Mother Marie gives her the address of a safe house, confident that Blanche will meet her there.
Scene 3: The Carmelites have been arrested and brought to Paris, where they are imprisoned in the Conciergerie. Granted permission to wash their only set of civilian clothes, the nuns have no choice but to don their habits once more. The Prioress comforts them, and also assumes the martyr’s vow. Constance is anxious about Blanche, but feels she will return to them. The jailer announces that the Revolutionary Tribunal has condemned them all to death.
Interlude 2: In a Paris street, Mother Marie secretly meets the Chaplain, who tells her of the fate of the nuns. Mother Marie is distraught at the idea of her sisters dying without her and feels dishonored, but the Chaplain tells her that she should submit to her deliverance as God’s will.
Scene 4: July 17, 1794. The nuns are brought to the Place de la Revolution. One by one, the Prioress leading, they go to the scaffold, singing the Salve Regina. Constance is the last to mount the scaffold and she does so she sees Blanche approaching. Blanche calmly and fearlessly accepts her fate and follows her sisters to the guillotine.