Scene 1: The courtyard of the Novodyevichy monastery near Moscow, 1598
Russia has been left without a tsar. The people, oppressed and apathetic, have been herded into the courtyard and ordered to beg Boris to consent to become tsar. As he continues to seem reluctant the crowd is ordered to reassemble the next day in the Kremlin.
Boris has agreed to become tsar and the coronation takes place. He is acclaimed first by Prince Shuisky and the boyars (nobles) and then by the people.
Oppressed by forebodings, Boris prays for a blessing on his reign.
Scene 1: A cell in the Chudov monastery in the Kremlin about five years later
The old monk Pimen is finishing his chronicle of Russia. The young monk Grigory, who shares his cell, asks him about his early life as a soldier in the service of Ivan the Terrible. He also asks particularly about the death of the Tsarevich Dimitri which Pimen had witnessed. Pimen tells Grigory that the tsarevich, murdered by the orders of Boris Godunov, would have been about Grigory's age if he had lived. Grigory declares that the punishment of God and man will strike Boris.
Scene 2. An inn on the Lithuanian frontier
Two vagrant monks who have run away from their monastery, Varlaam and Missail, arrive with Grigory, disguised as a peasant, who has joined with them.
Varlaam drunkenly sings a song about the siege of Kazan and its defeat by Ivan the Terrible. Grigory is particularly anxious to get across the border to Lithuania and the hostess explains that although the border is guarded there is another way across.
Police officers come in search of Grigory, who is being sought by the authorities. Since only Grigory claims to be able to read they give him the warrant to read. Coming to the description, he substitutes a description of Varlaam for the description of himself. As the police move towards Varlaam he seizes the warrant and painfully makes out the words - giving the true description of Grigory, who escapes out the window.
The interior of the tsar's apartments in the Moscow Kremlin
Xenia, the tsar's daughter, grieves for her dead betrothed while her brother Feodor and their nurse try to comfort her. Xenia and the nurse leave when Boris arrives. Feodor shows him the map of Russia he has been studying. Bidding him continue, Boris broods about his six year reign of peace which has brought him no joy. Russia is plagued by famine and unrest and men curse the name of Boris. The vision of the murdered Dimitri haunts him night and day.
A boyar announces that Prince Shuisky requests an audience and informs Boris that Shuisky is suspected of plotting against him. Boris warns his son to beware of Shuisky when he is tsar. When Shuisky appears Boris threatens him, but then forgives him. Shuisky tells him that a pretender to the throne has appeared in Lithuania and that he claims to be the Tsarevich Dimitri.
Sending Feodor away, Boris questions Shuisky, who saw the ded child, as to whether it was indeed Dimitri. Shuisky answers that it was and goes on to tell how the body remained uncorrupted and bathed in light. Boris sends him away. He feels as if he is suffocating. As a clockwork strikes, the bloodstained child seems to be in the room with him. He begs God for mercy for his sins.
Scene 1: Marina's dressing room in the castle of Sandomir in Poland
Marina is finishing her toilette, surrounded by a chorus of admiring handmaidens. She tells them she has no need of flattery or of lovers pining at her feet. She longs only for glory and greatness and these she hopes to find in the Pretender Dimitri. She looks forward to the time she will sit on the throne of Russia.
Rangoni, a jesuit, comes to proclaim to her her duty to convert the Russians to Catholicism when she is tsarina. She resents his attitude, but he cows her with threats of hellfire.
Scene 2: The garden of the castle of Sandomir
Dimitri is waiting for Marina but Rangoni comes to prod him into declaring his love for her. Marina, leaving her guests, comes to him and he professes his love; but she makes it clear that his love will only move her when he is tsar.
Thus jolted out of his lovesickness, he turns to thoughts of future glory and they are reconciled, to the joy of the watching Rangoni.
Scene 1: A hall in the Moscow Kremlin
The duma (assembly of the boyars) is in session, to pass judgment on the pretender. They pronounce a solemn condemnation of him and his followers. They wish for the advice of Shuisky who, although a rebel, is wise. He appears and they reproach him with treason because he now says that the tsarevich is alive. He declares that he has been maligned and then describes how he has just seen Boris, shivering with torment, haunted by the spirit of the murdered child, crying "begone child."
Boris enters the hall, uttering these very words. He is about to address the boyars, but Shuisky tells him a pilgrim waits outside to tell him a strange story. It is Pimen, who tells of a blind shepherd cured by the martyred Dimitri.
Deeply affected by the story, Boris feels that his death is upon him. He calls for his son and the penitential garment in which it was customary for a tsar to end his days, as a sign that he had renounced the world. He orders the boyars to leave and gives Feodor advice for his future rule. He begs the mercy of heaven not for himself but for his children. As the boyars return, he presents his son to them and dies.
Scene 2: A clearing in the forest near the town of Kromy
Vagabonds torment Krushchov, a boyar loyal to Boris whom they have caught. A simpleton arrives, followed by boys teasing him.
Varlaam and Missail come from Moscow with stories of Boris' tyranny. They say that the sufferings of Russia are a punishment for his sins. Two jesuits, although supporters of Dimitri, are dragged off to be hanged as heretics. Dimitri appears and is proclaimed tsar by his motley collection of followers. He prepares to march on Moscow.
The simpleton laments for the future of Russia and her hungry people.