Leaving the chapel, Vasya meets Kasyan at the gate. When an escaped chestnut mare from the market comes galloping through the streets, Vasya catches her. Chelubey and his men arrive, revealing that Chelubey has bought the horse. Vasya rashly wagers Solovey that she can ride the frightened horse before the third hour rings.

In the market square before a crowd, Vasya, who can speak the language of horses, calms the mare. She removes the halter and drives the horse in circles until the mare seeks her companionship. Vasya successfully mounts and rides her. The crowd erupts in cheers, calling her Vasilii the Brave. Chelubey concedes defeat, but his eyes promise revenge. Vasya names the mare Zima.

Kasyan warns Vasya that she has made a dangerous enemy. Back at the paddock, Vasya tells Kasyan about the bandit attack and her suspicions about Chelubey. Kasyan believes her and advises finding proof before approaching Dmitrii, promising to send men to investigate the burned villages.

That evening, Vasya attends the cathedral service and is struck by its beauty. At Dmitrii’s feast, Sasha confronts her about the day’s recklessness. Vasya angrily retorts that she cannot live in the terem any more than he can live as a simple monk. Seeing his pain, she resolves to leave Moscow the next day.

When Vasya tries to tell Dmitrii about Chelubey, Kasyan loudly interrupts, challenging her to a horse race the following day. He later explains that he was preventing her indiscretion. He cryptically mentions having been in the palace long ago, searching for something lost.

As the feast continues, Vasya becomes aware of chyerti watching from the shadows. She sees Morozko standing in the doorway, visible only to her and the spirits. He explains that Maslenitsa marks the waning of his power and invites her to ride. 

They gallop along the frozen river. Vasya expresses her frustration about being born a girl and asks where she belongs. Morozko admits that he has no answer. He kisses her, then abruptly pulls away. He warns her of a shadow over Moscow that he cannot clearly see. Hurt and confused, Vasya rides away. Later that night, a red light streaks across the sky. Kasyan sees it and smiles.

On the morning of the race, Vasya resolves to tell Dmitrii about Chelubey that night and leave Moscow. Sasha reveals that his investigation has made him suspect Chelubey is an impostor with a powerful helper.

Kasyan arrives for the race on a magnificent golden mare named Zolotaya. As they ride to the starting line, Kasyan wagers his horse against Vasya’s hand in marriage, revealing that he knows she is a girl. The race begins on the frozen river. Just before the finish, Kasyan rips off Vasya’s hood, exposing her long hair to the stunned crowd.

Solovey wins, but Kasyan seizes Vasya and holds a knife to her throat, and Sasha draws his sword but is surrounded. Kasyan tells Dmitrii he has exposed a great lie, blaming Sasha for the deception. When Dmitrii demands proof, Kasyan tears open Vasya’s clothes, leaving her half-naked before the crowd. The mob calls for her to be burned as a witch. Father Andrei intervenes to prevent a riot. Dmitrii orders Vasya confined in Olga’s tower and Sasha imprisoned in his monastery.

Olga realizes that Vasya’s actions implicate her family. When Dmitrii’s guards bring Vasya into the terem, Olga orders her bathed and locked in her room. Meanwhile, rumors of witchcraft spread through Moscow, and Kasyan visits Konstantin, promising the priest revenge on Vasya in exchange for his obedience.

That night, the ghost that has been haunting Marya appears. Vasya offers her blood, allowing the spirit to speak. The ghost warns that Kasyan plans to take a new wife and Moscow that very night, with the Tatars’ help. Morozko appears, revealing that Kasyan is the immortal sorcerer Kaschei. Kasyan’s magic had prevented Morozko from seeing the plot earlier.

Olga interrupts, announcing that Kasyan has come to see Vasya. He admits that he sent the men who attacked her in Chudovo, and Konstantin is ready to denounce her as a witch. He offers to save her family if she marries him. She agrees, but when he tries to put a gold necklace with a red stone around her neck, Vasya’s sapphire talisman glows. He strikes her in a rage, demanding she destroy the talisman before their wedding the next day.

Vasya tells Olga she has accepted the match. As she tries to warn Olga that Kasyan and Chelubey plan to depose Dmitrii that night, Olga is seized by labor pains.

Vasya assists as Olga labors in the bathhouse. As Olga weakens, Vasya’s sapphire flares, and Morozko appears as the death-god. The bathhouse fades, and Vasya finds herself with Olga in a spectral wood. Morozko declares that either Olga or her unborn daughter must die. Olga chooses to sacrifice herself for her daughter. Vasya refuses and uses all her strength to pull Olga back to the physical world.

Back in the bathhouse, Konstantin is intoning last rites. The baby is born blue and unmoving. Vasya sees Morozko gently take the baby’s spirit away. Devastated, Olga tells Vasya she has killed her daughter. Konstantin seizes Vasya, denouncing her as a witch who killed her father and now her sister’s child.

In the antechamber, Konstantin confronts Vasya, mentioning Kasyan’s promise of vengeance and demanding she submit to him. Vasya knees him in the groin and escapes into the night.

In the dooryard, Morozko appears on his white mare. Vasya bitterly accuses him of knowing Olga’s child would die. Morozko admits he would have spared her the pain, but he says Olga was right to condemn her for making the choice.

Grieving and feeling betrayed, Vasya demands the truth about her sapphire necklace. Morozko reveals the truth about her father’s death: He guided her father to Medved the Bear’s clearing, where Pyotr willingly sacrificed himself. Morozko reveals that as belief in the old gods wanes, he is losing his strength. He created the jewel for her to bind her magical strength to his own, sustaining himself. He claims saving her life twice makes it fair.

Feeling used as a tool, Vasya rejects him and their bond. Morozko warns that the sorcerer will find her without his protection. Vasya refuses, saying she will not die as his creature. She lets the sapphire fall; Morozko catches it, and it melts into water in his palm. Vasya turns and walks away across the snow.